Oil pressure drops when RPM's increase [Archive] - Team Camaro Tech

: Oil pressure drops when RPM's increase


whytry
May 18th, 07, 10:22 AM
On my Camaro, I thought I had a big problem when the oil pressure all of the sudden dropped to 10-20 psi at cruise speeds, and below 15 psi when hot and cruising.... Changed to mech gauge, and replaced filter (FRAM) and oil pressure came back to reasonable ranges 25-30 psi hot idle and cruising. Drove it around a little more and all seemed ok. Well drove it around a little today and noticed the oil pressure dropping when at WOT from about 3000 to 6000 and let off when I saw the oil pressure at around 15..... Let car come back to idle and stayed around 15-20. Would rev and it would come up to around 25 but not much higher..... If I recall I have the HV55 pump and stock milodon pan, where should I start?

markr
May 18th, 07, 11:47 AM
Wow...I would have guessed you had a high volume oil pump.
That's a classic symptom.

Is the Milodon oil pan a 5 qt ?
And is it shaped similar to stock ? (no kick outs etc.)
Is it a baffled pan ?

BlackoutSteve
May 18th, 07, 01:31 PM
Yep, HV pump and stock pan..
You need to increase your pan volume.

Try over-filling by 1 quart and see if it makes a difference. If so, that's your problem..

whytry
May 18th, 07, 02:09 PM
The pan is the stock replacement from Milodon, no kickouts, etc. It is the exact same shape as stock.

Overfilling it by a quart, ok will try that out this weekend hopefully......

onovakind67
May 18th, 07, 04:04 PM
Overfilling the pan will just increase the windage and the oil will be frothy. This will definitely decrease your oil pressure.

whytry
May 18th, 07, 05:56 PM
update - I drove it around for about 15 miles and once it was about 10 miles oil pressure was around 15 psi. would drop to 10ish while on the throttle, but let off gas and was back to 15 psi again... would not increase much more than that... could the oil be a little thin from the heat? mobil 1 10w-30 synthetic...... ideas?

Z15CAM
May 18th, 07, 06:34 PM
Brad: I don't know about other performance enthusiasts but I always considered 10w30 oils, Synthetic or Not, as Pony Piss. In my opinion, 10w30 will not handle the surface to surface pressures of Hi-Perf Engines. I prefer to use 15w40 and will use 20w50 if I can not find 15w40. Stay away from 10W40 as there are too many polymers in it. I highly Recommend Rotella Diesel Oil 15w40 as it is ZINC Based and will save your Flat Tapped Cam. Valvoline also makes a Race Blend Oil, advertised as "Off Road Use" which is also ZINC based. I also recommend ZINC Based Oils for Blocks that were originally designed for Flat Tappet then Retro Fitted to Roller Cams because of the poor lifter bore alignments found in Flat Tapped Engines.

It is not unusual particularly with 10w30 Oil for the Oil Pressure to drop considerably after the engine has warmed up and driven for awhile; however, the Oil Pressure should increase some what proportionately as the revs increase NOT Decrease, even with 10w30.

It is possible that you have larger bearing clearances then what is considered standard and as the engine heats up and is revved, the 10w30 simply can not fill the gap; hence the expression, "Pony Piss". Other then this, it is what Mark and Steve suggests that the Hi-Volume Pump has simply pumped the oil pan dry and you need more reserve by adding another quart or possibly the oil pump pressure relief valve may be stuck. Here's another thing, it is possible that the clearance between the Oil Pump Pickup and bottom of the oil pan is too small.

If you are not experiencing engine knocks, indicating a bad bearing, I would try using higher viscosity oil such as 15w40 and see what happens.

fatblock
May 18th, 07, 06:37 PM
Brad..your clearances may require a 20-50 weight.I would try that first.The 4 qt oil pan will not be depleted at idle speed,increasing the capacity will result in aerated oil and further drops in pressure.If the 20-50 does not help..the oil pump pressure relief valve may be stuck in its bore.

ace's68
May 18th, 07, 08:31 PM
My friend had a problem at WOT with his oil pump pumping faster than the oil could drain back which caused a drop in psi at WOT.

onovakind67
May 18th, 07, 09:08 PM
My friend had a problem at WOT with his oil pump pumping faster than the oil could drain back which caused a drop in psi at WOT.

What does it do at half throttle?

BlackoutSteve
May 18th, 07, 09:18 PM
Overfilling the pan will just increase the windage and the oil will be frothy. This will definitely decrease your oil pressure.

Overfilling by just one quart will not actually overfill the pan if the engine has poor oil return. This is an easy way to quickly find out if pan volume is less than enough.

As for oil weights, I don't think a 30 weight is a cause for concern. Most times a 50 weight will appear to provide better oil pressure simply because of the gauge's location between the oil pump and main gallery (BBC), or on the same oil feed gallery from pump to main (SBC). The gauge sees the pressure created by the pump trying to force a thicker oil through the engine, yet less pressure arrives at the far end.
A lighter oil shows as less pressure on the gauge because it is of less restriction and flows easier to the far end with less effort.
But at the same time it's true for the lighter oil to bleed off faster requiring more oil to be moved through the engine, or a slight drop in pressure.
So I am not for or against 30 vs 50 weight oil, just something to keep in mind that the factory oil pressure port's location is not optimum.
A better place for your gauge's sender is the front of the main gallery. This will provide a more relevant reading of mains pressure in a worst-case-scenario. In other words, I don't care how high my oil pressure is, I care about how low it is.

Maybe you're overheating your oil. You say your pressure drops after WOT. Got a pan gauge or IR gun?

whytry
May 18th, 07, 10:28 PM
THanks for the input guys! I will take a look at putting something better than 10W30 in there then. I am running a Hyd Roller Retro fit cam, if that helps with running a ZINC based oil or not.....

At part throttle, it stays constant @ 15 psi, when I am building boost and at WOT it seems to drop.... When the motor is cold it increases with RPM's until about 65 psi then holds steady.... But once its warmed up can't get it to go above 25 psi. I have 2 oil pressure tests, one is a 10 psi warning light connected to the line right where the oil filter is, and the other running to the gauge is on the drivers side front portion of the motor...

I don't have a IR temp gauge, that might be one of my next tool purchases... But I do know the pan is pretty hot to the touch after driving it today...

Forgive my ignorance, but can I access the oil pump pressure relief valve without pulling the pan? I have been told it is a big pain to try to pull the pan without pulling the motor...

onovakind67
May 19th, 07, 12:47 AM
Overfilling by just one quart will not actually overfill the pan if the engine has poor oil return. This is an easy way to quickly find out if pan volume is less than enough.



When is overfilling not overfilling? Could less than enough actually be more than plenty?

It's normal for your oilpan to be warm to the touch, normal oil temperatures are somewhat higher than the engine coolant temperature. You certainly won't be able to hold your hand on it.

BlackoutSteve
May 19th, 07, 12:56 AM
Maybe, but if a heap of oil is up the top of the engine and taking it's sweet time to return to the pan, the pan is not actually over-filled during that time right?

Anyway, I've seen this test work several times to indicate pans that are too small or otherwise. It does work. :)

kustomwerker
May 19th, 07, 05:56 AM
the fact that you`re trying to run a boosted sbc with 15 lbs of oil pressure scares me!!!but its not my motor...lmao...(sorry)anyway, did you put a fram filter back on the motor???if so, pull it back off, and get a good filter...fram is notorius for doing this exact same thing in our 70 nova ...(blown 383) but before we notice a pressure drop, the filter usually splits...happened twice before we vowed to badmouth fram filters every chance we got...lol...synthetic oil takes the heat better than conventional oils, but i`d want to go with a zinc based oil like the earlier posts said...(keep in mind that rotella is phasing out zinc also!!!)the bypass valve is also a great place to look, but i`d start with the filter first...fact is if you put a blower on an older motor, you can make alot of carbon in the oil, due to ring seapage...you cant see the blowby because it wont show at the breather until under boost...not that this is your problem, but just something to think about... SCRAP THE FRAM...

77wolf10.85
May 19th, 07, 06:11 AM
.. When the motor is cold it increases with RPM's until about 65 psi then holds steady.... But once its warmed up can't get it to go above 25 psi. I have 2 oil pressure tests, ..

viscosity and or volume issue. NOT a stuck bypass.

I haven't noticed in this thread any mention of checking the contents of your oil filter, that's always the first thing I look at. Just pull it and dump it across your closed fingers, what's it look like? Clean, put it back on. Sparklies in it, uh oh. STOP and reassess. If I'm on the right thread this is a new engine, talk to your builder.

If it was clean and you put it back on, do this after talking to your builder. He always has first input....

Run the pee out of it COLD and tell us if the pressure stays up at WOT

Now people are going to say I'm telling you to abuse a cold engine, and to them I say go in-frame overhaul some 1000KW gen set engines and watch your brand new overhaul get started at max RPM with no chance of idle speed ever for it's entire life.....

77wolf10.85
May 19th, 07, 06:26 AM
viscosity and or volume issue. NOT a stuck bypass.

I haven't noticed in this thread any mention of checking the contents of your oil filter, that's always the first thing I look at. Just pull it and dump it across your closed fingers, what's it look like? Clean, put it back on. Sparklies in it, uh oh. STOP and reassess. If I'm on the right thread this is a new engine, talk to your builder.

If it was clean and you put it back on, do this after talking to your builder. He always has first input....

Run the pee out of it COLD and tell us if the pressure stays up at WOT

Now people are going to say I'm telling you to abuse a cold engine, and to them I say go in-frame overhaul some 1000KW gen set engines and watch your brand new overhaul get started at max RPM with no chance of idle speed ever for it's entire life.....


Got my threads mixed up. What werker said, get a WIX racing filter first. Was oil in the filter pretty when you changed it? If the filter change to WIX racing doesn't fix it I still would do the cold WOT check. But I want to clarify COLD.... I don't mean immediately after startup, I mean before your oil temp begins to increase and approach normal temps. I'm not that mean to my machines even though I see them tolerate it.

Z15CAM
May 19th, 07, 09:33 AM
Brad: You're running a Blower? You also mention you're running a Retro Mechanical Roller Cam. Just a thought but some Roller Lifter designs, unless modified, will actually Block Oil Flow in the Lifter Galleries at Full Lift. I do not think this would be an issue below .650" but something to consider. I don't know what effect the above situation would have on Oil Pressure.

Another thing to consider, perhaps your Oil Gauge is Defective.

There are some good diagnoses posted here, keep us informed - Good Luck.

Fred Ficarra
May 19th, 07, 11:01 AM
Brad! Please hurry. Us lurkers are getting anxious for some answers.:yes:
One thing; When you do that oil cleanliness test, no matter how clean it is, DON'T return the Fram to service. Sure, save the Mobil 1 if you must. Just pour it into a Wix. I parted company with Fram nearly 30 years ago, right after they were sold. (forget to who) All their stuff I was using got cheaper. And since, from what I've read, it only seems to have gotten worse. But they're trying. At least it looks that way. They came out with a new line of products that are touted as ultra high performance. Might be as good as everybody elses standard products. Haven't heard. And good luck! Just hurry.:yes:

whytry
May 21st, 07, 09:12 AM
Sorry for the delays' 11 month old son is sick, so I did not get any "real" chances to get this worked on over the weekend. I am hoping to get some of these tests done today maybe. One of the ones I was able to do was pull the fram filter apart, and there is some "glittery" look to the oil from the filter, but when I poured it over my hands I was unable to feel anything when rubbing my fingers together as if it had chucks of metal in there, but there was a goldish shimmer to it.... I did replace it with another FRAM filter because I had one in the garage, and it was almost midnight on Saturday and I wanted see if anything changed in the morning... I am getting the WIX today on my lunch hour...... Updates to follow, hopefully tonight...

whytry
May 21st, 07, 09:14 AM
I have replaced the oil pressure sending unit already and even ran an electrical gauge and as soon as I change the gauge and try it it does the same thing, cold around 50 psi, warmed up around 15 psi.... I know Jody had me test to see if pressure dropped when reved up, and it does not it does climb but not much....

77wolf10.85
May 21st, 07, 09:18 AM
Hope your boy gets better. That's most important.

tfultz
May 21st, 07, 09:35 AM
the first thing I would try is taking the oil filter off and removing the oil filter by pass assembly that the filter screws on to (only two bolts) . Clean the pressure relife spring and work the bypass valve open and closed as you spray it with carb or brake cleaner. Check to see if the valve assembly is seating squarley and that it is not damaged, if in dought R&R it.
The 2nd thing I would do is replace the pump with a HV-55 unit and use a steel pined pump drive shaft as well.

Just my II cents.

68Holdon
May 21st, 07, 10:14 AM
Worn Cam Bearings????

whytry
May 21st, 07, 08:53 PM
Hope your boy gets better. That's most important. Thanks!! Me too....



the first thing I would try is taking the oil filter off and removing the oil filter by pass assembly that the filter screws on to (only two bolts) . Clean the pressure relife spring and work the bypass valve open and closed as you spray it with carb or brake cleaner. Check to see if the valve assembly is seating squarley and that it is not damaged, if in dought R&R it.
The 2nd thing I would do is replace the pump with a HV-55 unit and use a steel pined pump drive shaft as well.

Just my II cents.


OK, I changed to the KN filter HP2002, took the Fram filter off, when I unscrewed it there was no oil than ran down the sides, which I thought was wierd...... I pulled the filter off, drained it through a paint strainer, and there was nothing in the paint strainer... Pulled off the oil filter bypass, I did not have a spring or anything. I took off the 2 bolts and pulled it out of the car. I had an allen plug in the opening.... That was all I could find, I could not find a spring anywhere or check valve or anything...... Unless the spring, etc is somewhere else I did not look.

After I put it back together, I let the car warm up checked the pressure and it was good around 60 psi, let the car warm up more and was able to see the pressure begin to lower to 50, 40, 30..... It held at around 30 for about 5 minutes, so I went and drove around for about 10 minutes, it was around 20 psi now, so I started doing some tests. Cruising around and then give it 3/4 throttle, pressure increases then to about 30 psi then begins to fall so I get out of it. Come to a stop, pressure is now at 20 psi. Begin cruising around go through 1,2,3, and into 4th, seems to be hovering around 20-25 psi. Downshift to 3rd, pressure goes to 25 then begins to drop to 10-15 psi so I let off, it comes back to 17-20 psi. Oil level is good from looking at the lokar cable, but can't tell when on it how much oil is in pan.... If the pickup fell off would I still get oil pressure at all or would it severly be hampered? Next is to drain the oil tomorrow replace with 20-50w, should I use Royal Purple?

77wolf10.85
May 22nd, 07, 03:10 AM
I run 20-50 roy purp, but for purposes of your troubleshooting I would stick to mineral oil for expense reasons. The sparklies you said came out of your filter bugs me. How many miles on this engine?

Your filter bypass has been plugged. I consider this good medicine. Seems to scare some folks. It is not the problem. In this case it prevented those sparklies from going back into your lube system.

Not familiar with KN oil filters, are they worth installing?

Don't forget to add one extra quart to test the volume theory. And have you considered my "cold" WOT test?

whytry
May 22nd, 07, 07:57 AM
I run 20-50 roy purp, but for purposes of your troubleshooting I would stick to mineral oil for expense reasons. The sparklies you said came out of your filter bugs me. How many miles on this engine?

Your filter bypass has been plugged. I consider this good medicine. Seems to scare some folks. It is not the problem. In this case it prevented those sparklies from going back into your lube system.

Not familiar with KN oil filters, are they worth installing?

Don't forget to add one extra quart to test the volume theory. And have you considered my "cold" WOT test?

Oops, I knew I forgot something, I did your "cold" test and pressure was good around 35-40 @ idle and close to 65 at WOT.... I timed it this time, after about 7 minutes of sitting in the driveway @ idle and about 10 minutes of driving is when the oil pressure drops to 15-20...

I ran a paint strainer through the oil in the filter and there was nothing in the filter afterwards, but the 1st time I changed the filter is when I saw sparkles. The motor is 3.5 years old but only has maybe 1800 miles on it. It was in paint for 10 months, was at my parents house while we moved for 4 months too. So not as much driving as I would like see. I was hoping to change that this summer until this happened.....

So just change to oil to a mineral 20w50 and retest right?

77wolf10.85
May 22nd, 07, 08:46 AM
Yes, just put some 20-50 mineral in it and see if it doesn't stay up better hot. I have also used straight 30 and straight 40, know guys who use strt 50. Not the point.

If you had 65# oil pressure WOT cold oil, you have a viscosity issue. Thin oil is getting out of your running clearances faster than the pump can maintain flow volume.

I have a bad feeling from you finding the sparklies first time you pulled your filter. Was it thick sparkly made your stomach turn to look at, or just a little?

whytry
May 22nd, 07, 09:40 AM
It seemed to me like just a little, but enough that while I was draining the filter I noticed it. That's when I cut the filter open and drained it all the way to see if I was seeing things or not.

It was not thick enough for me to pour it over my closed fingers and to feel anything more than oil.... Just went and picked up some 20w50 castrol and will put that in later today... Will post up results... thx

Fred Ficarra
May 22nd, 07, 12:17 PM
He's using Mobil1, right men? The stuff is known for lower pressures when warm. But he should have protection. Hmm.

67funcar
May 22nd, 07, 12:40 PM
It will be interesting to hear if the heavier oil changes your problem. I'm guessing it will not. Any good oil of 5W30 or heavier should provide good oil pressure in a motor that has proper bearing clearances.

Your problem sounds to me like oil pump starvation because it worsens when you increase RPM. Either your high volume pump is putting most of the oil to the top of the motor (and leaving too little oil in the sump) or you may have a situation where your oil is foaming due to too much oil in the engine. At higher RPMs the crank can thrash the oil and cause frothing and pump cavitation. This can happen when the wrong dipstick is used and the oil pan is filled too full. Pump starvation could also be caused by the pick-up being too close to the bottom of the pan or a problem with the pump itself. I don't think your pick-up has fallen off because you would have problems with cold oil too and before you rev the motor.

If all else fails, consider the possibility of oil foaming. Do you know how much oil is in the engine now?

whytry
May 22nd, 07, 01:36 PM
I did not think of the pan being to close to the pickup, I do have a small dent in the bottom of the pan in the center near the back......

From what I recall a BBC, needs 4-4.5 qts in pan and 1 in filter right? I have a little more than 5 in there now, actually closer to 5.5 now that I think of it. I have the Milodon stock replacement pan and the Lokar dipstick, I called Lokar and they told me with a stock pan their dipstick is accurate......

77wolf10.85
May 22nd, 07, 01:42 PM
If your pickup was too close to the pan you would NOT have had 65# WOT "cold" oil

whytry
May 23rd, 07, 07:42 AM
Thanks Tim, OK drained the Mobil 1 10w30 last night, pretty clean, I could not see the same sparklies I did when I changed the filter, also the try to drain as much as possible I jacked up the passenger side higher than the drivers side the get the pan as empty as possible. Refilled with Castrol 20w50, and waited about 20 minutes (are dinner). Went back outside started her up and oil pressure was about 70! I figured cold, plus higher viscosity..... Let her warm up a bit, and oil pressure was still around 35, headed out for a drive, put about 10 minutes of driving, and the oil pressure was at 30. I was pretty happy with that. Got on the highway, part throttle held at 35 through, 3rd and 4th, went into 5th and was holding tight around 35. Ok, exited about 2 miles up the road and turned around and did it again, shifted into 3rd and hit WOT, oil pressure rose to 40 then started to drop to 30, shifted into 4th, still @ WOT, pressure increased to 35ish and then came back down to 20-25 before getting out of it (was doing close to 90) and shifted into 5th and oil pressure came back to 30-35....... So is it a good bet I am sucking my pan almost dry at WOT? I put 5.5 qts in it exactly.....

67funcar
May 23rd, 07, 08:01 AM
I think it is certainly possible that you are sucking almost dry with the HV pump. Does the oil pressure gauge ever jump or quiver (as if the pump were sucking dry momentarily) or is it steady?

You might try adding a quart to see if the extra oil keeps the pump pick-up submerged. If that makes it worse, it may be foaming.

The higher viscosity oil (20-50) gave you a little more oil pressure (as it should) but your problem is still there.

whytry
May 23rd, 07, 08:28 AM
That is what I was thinking too, I was hoping to be on the right path. The oil pressure does not jump ro quiver, it is a pretty steady drop, it holds steady until about 4000 rpm then starts decreasing, but once I shift it comes back and does it all over again.... But it was nice at cruise speeds to see it come back up..... Where before it would just stay low....

Vegas69
May 23rd, 07, 09:05 AM
Look at his post at the top of the page. He said their was goldish flakes in the oil filter. Sounds like bearing material to me. A sign of a bad main bearing is low oil pressure hot and definitely copper in the oil. Hope I am wrong for your sake.

Vegas69
May 23rd, 07, 09:08 AM
Sorry for the delays' 11 month old son is sick, so I did not get any "real" chances to get this worked on over the weekend. I am hoping to get some of these tests done today maybe. One of the ones I was able to do was pull the fram filter apart, and there is some "glittery" look to the oil from the filter, but when I poured it over my hands I was unable to feel anything when rubbing my fingers together as if it had chucks of metal in there, but there was a goldish shimmer to it.... I did replace it with another FRAM filter because I had one in the garage, and it was almost midnight on Saturday and I wanted see if anything changed in the morning... I am getting the WIX today on my lunch hour...... Updates to follow, hopefully tonight... This is the post

77wolf10.85
May 23rd, 07, 01:52 PM
Brad
Now you know because of the higher pressure until WOT that you had a viscosity/clearance issue. The WOT falloff is next, and you need to do like everyone is telling you and stick an extra quart in it and haul a$$, see what she does.

But man I still feel bad over the sparklies you found first time you pulled your filter.

You say this engine has 1800 miles on it . Can I infer that this same engine did not previously exhibit any of these symptoms? And that you are now on your 3rd filter since starting the thread?

copied and pasted your first post

On my Camaro, I thought I had a big problem when the oil pressure all of the sudden dropped to 10-20 psi at cruise speeds, and below 15 psi when hot and cruising.... Changed to mech gauge, and replaced filter (FRAM) and oil pressure came back to reasonable ranges 25-30 psi hot idle and cruising. Drove it around a little more and all seemed ok. Well drove it around a little today and noticed the oil pressure dropping when at WOT from about 3000 to 6000 and let off when I saw the oil pressure at around 15..... Let car come back to idle and stayed around 15-20. Would rev and it would come up to around 25 but not much higher..... If I recall I have the HV55 pump and stock milodon pan, where should I start?

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I am inclined to think it is not a low oil level problem. Because when you did the "cold WOT" test your pressure stayed up at WOT 2 things were eliminated, volume and cavitation whether from low pickup strainer or oil all on top. But you still need to do the overfull thing.

whytry
May 23rd, 07, 03:04 PM
Will do the extra qt tonight when I get home. The motor has approx 1800 miles on it, but I would have to say it would probably be more if I added in the fact of tuning, etc.... Just so I am sure I explained this right, I could not trap any peices of the sparklies in the paint strainers, either in the pan or the filter when drained through them. What I did see was a different color or tint (more goldish sparkly color) in some parts of the oil as it was drained from the 1st filter.... After cutting the filter open I did not see anythingon the paper element... I had to check my records of the last oil change before I had this issue, and because of a small oil leak and the fact that it sat for a long time at paint without being started I did add one of those oil stop leak treatments to this last oil treatment, but I forgot to notate which one I used. Just more of an FYI...

whytry
May 23rd, 07, 08:50 PM
Added the extra qt, still had same problem.... Oil pressure would drop to 10psi after going through 2,3,4 @ WOT..... let of and would come back to 25 psi... Now I'm just guessing here, but I have a feeling I will be missing the upcoming show........

Vegas69
May 23rd, 07, 11:22 PM
Did the pick up fall off?

77wolf10.85
May 24th, 07, 03:37 AM
Brad
Can I infer that this same engine did not previously exhibit any of these symptoms?
copied and pasted your first post

On my Camaro, I thought I had a big problem when the oil pressure all of the sudden dropped to 10-20 psi at cruise speeds, and below 15 psi when hot and cruising.... Changed to mech gauge, and replaced filter (FRAM) and oil pressure came back to reasonable ranges 25-30 psi hot idle and cruising. Drove it around a little more and all seemed ok. Well drove it around a little today and noticed the oil pressure dropping when at WOT from about 3000 to 6000 and let off when I saw the oil pressure at around 15..... Let car come back to idle and stayed around 15-20. Would rev and it would come up to around 25 but not much higher..... If I recall I have the HV55 pump and stock milodon pan, where should I start?

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I am inclined to think it is not a low oil level problem. Because when you did the "cold WOT" test your pressure stayed up at WOT 2 things were eliminated, volume and cavitation whether from low pickup strainer or oil all on top. But you still need to do the overfull thing.

This engine is 3 1/2 yrs old, everything I've read about the Melling oil pumps cracking began with a GM requested alteration 2 yrs ago.

Is there any way the procharger can be involved in this?

How was the oil pressure before the car went to paint for those 10 months? Do you trust the people who had it that long?

whytry
May 24th, 07, 08:37 AM
I don't know, I did notice that there way some oil on the top of the driverside valve cover where the breather is, almost like it was spitting out the breather...

The downside to the paint, was there was no Procharger then, it was last driven with the procharger in mock up stages so I could not tell you... I wanted to make any modifications to the engine bay prior to paint just incase there was something that needed to be cut here or filed down there, etc. Once it was in place and ready to go it went to paint. The guy who painted it, I really would be amazed if he did something to it becuase he still comes over all the time to hang out.... We are planning on driving to the car show together. So I would think he did not do anything out of the ordinary... I do know the motor had decent oil pressure before I went to forced induction.... By decent I mean it would still run low pressure around 15-20 @ idle, but when it was not forced induction I was not that worried about it because it never triggered my 10 psi warning light....

77wolf10.85
May 24th, 07, 02:21 PM
Did the oil pressure at WOT stay up before prochargers?

Prochargers are belt driven and sealed cartridges aren't they? I've never seen one up close and personal.

If there was no WOT oil pressure falloff before forced induction, and the lube system is not altered to supply turbo cartridges, and the turbo belt is not too tight and stressing the front main, then... Try turning your boost down to decrease BMEP forces pushing the crank downward, if you have an adjustable wastegate. And then do another WOT test.


Lots of people don't believe bad mains can cause oil pressure to fall under load but it can.
The force of the pistons pushing the crank into the lower main creates an exagerated crescent moon clearance at the top bearing half, and sploosh out the oil goes and pressure drops because volume requirements just increased.
Contrasted to light loads where hydrodynamics keeps more oil film under the crank, you still have a crescent shaped clearance but not as exagerated and the oil pump is capable of supplying an adequate volume to create pressure.
Journals never run centered in their bearing bore, it is always offset giving more clearance at one point than the rest, and this very eccentric is how oil is introduced to the bearing and shaft. Oil pressure only supplies the oil; hydrodynamics of the rotating shaft inside an eccentric space moves the oil.http://us.i1.yimg.com/us.yimg.com/i/edu/dictionary/theccent.jpg (http://education.yahoo.com/reference/dictionary/image;_ylt=AuD8UwKNYj6KdygQEISgwWyugMMF?id=E002330 0&path=a4eccent.jpg)
Each journal is contantly moving the eccentric with rotation, and as forces alter. Crankshafts earn their keep, whole lot of bending goin on.


Best pic I could find on short notice, ignore some of the circles. This pic came up from Yahoo Dictionary, eccentric

whytry
May 25th, 07, 09:50 AM
Tim, it was higher but I never noticed it before because after I installed the Procharger bypass valve, is when I noticed the oil pressure dropping below 10 psi, warning light came one... Otherwise I think it held pressure but if I recall it would never constantly build pressure @ WOT, it would creep up and then either hold steady or fall slightly.... Almost all of the miles on the motor are from the old setup w/o Procharger, this was added probably within the last 300 miles at most....

One thing I noticed is it looks like the pressure drops a little more now that the extra qt is added..... Still at cruising speeds its great but at WOT it still drops. To start eliminating some remaining questions I got a new pan, if the pump is sucking the pan dry, the new Milodon Low profile sump pan 7qt + filter will help.... I can also check to see if the pickup fell off at this point in time too. I am hoping to be able to pull the pan this weekend and replace it with the new oil pump and pickup as well. If all goes well I will have more information and answers later this weekend. Any tips on changing the pan without pulling the motor? Or anything else I can check while doing this?

zdld17
May 25th, 07, 09:56 AM
Have I missed someone mentioning a windge tray? I know the metal flakes tell something also but I would think that a motor like this needs one, perhaps the one that is built into the pan, removable type. .

77wolf10.85
May 25th, 07, 11:21 AM
Pulling pan in car, I recommend a separate post. I've never tried on a big block in a 68 Camaro. Would pulling the engine be easier? Idunno, sorry. I know you just did paint. DammitDammitDammit

I would pull main caps as my primary objective, and all the rod caps too just because I was there. Rolling new bearings in is a drag until you get the hang of it, then it's a breeze. With the engine out and upside down you could plastigage your mains. Also check crank thrust, you had golden or yellow tint in oil once. It's either the stop leak treatment you used or a bearing(s) down to copper. I know you couldn't feel the metal in your hand. You usually can't until it is in terminal stages.Thrust flange is fist place to strike copper if they are plated at all the plating is extremely thin. I can't remember if big block thrust flange has a lead tin overlay.
If you get the pan off in the car, look up towards the cam bushings. Sometimes when a bearing goes a small flake will lodge at the side of the journal. It'll be murder to see the cam bushings areas, and you'll have to roll the engine a bunch of times, lots of lights and mirrors here. I don't think it's a cam bushing or it would be an all the time low pressure problem.

Where was it leaking oil that you used stop leak gasket/seal in a can for?

Don is asking about windage tray, and I'm curious about that too.

When you get your old pan on the ground, I'd like you to check the level of fluid at different capacities. Set the pan on the ground and lay a level on the gasket rail and level the pan. Then pour a gallon of water in it and compare the water level to the forward trough area of the pan. Measure how much additional water you have to add to make the level rise to the trough section.
I just took a small block pan and put a gallon in it, then I had an old 427 oil pump I held the mating face flush with the rear half moon while I added more water, got tired of that game and threw the whole damn pump in the pan.
4 2/3 qts the water was just peeking out from under the windage tray.
5 quarts had about 1/8 to 1/4 " laying up in the front of the pan, and I figger that much is going to be dispersed through the system with oil flowing. Of course that's sitting still, no g's or cornering. Beats me if it proves anything.

67funcar
May 25th, 07, 01:40 PM
I might be barking up the wrong tree but it still makes me think about possible oil foaming, especially when you say that adding a quart may have made it worse.
Before you go to all the work of dropping the pan, inspecting bearings, etc. I would be tempted to drain 2 quarts of oil and see if that changes anything. The reason I say this is my friend and I just went through all this with his new 383. He insisted he did not have too much oil in his stock pan and many others had offered suggestions about bearings, etc. etc. His symptoms were the same as yours. He drained some oil and problem went away. As it turned out he had the wrong dipstick.

I know this may not apply to your situation but it is easy to try this before all the hard work starts.

Let us know.

77wolf10.85
May 25th, 07, 02:04 PM
I know this may not apply to your situation but it is easy to try this before all the hard work starts.

Let us know.

It is one more thing to try before you embark.
Even though you've drained oil and refilled with exactly 5 quarts, and now added a 6th...

whytry
May 25th, 07, 04:11 PM
From your post earlier Tim, I have the stock replacement pan on the motor with no windage tray currently, with the Milodon dipstick... The small oil leak I have is from the back of the motor, from what I can tell, valve covers are dry, back of the intake is dry, I have a couple drops of oil on the bottom of the bellhousing, and additional drops on the starter, and bottom of the pan. I had to pull the pan once before when my buddy dropped a bolt and it fell down the dist hole and luckily into the pan. I havd to lowered the pan enough to get my hands in there and grab the bolt. I then cleaned everything off and tightened it back up, at that time the motor only had about 500 miles on it... If I get the pan off I will fill it with water as you said above and let you know what I come up with...

Agreed, one more thing to try before I tear the old pan off... Will do this tonight. Like you guys said its one more thing to try.....

I am hoping not to have to pull the motor, for 2 main reasons, no picker, and new paint.... Hopefully I can get this stuff fixed before to long. I have a friend on here that will let me borrow a picker if needed but I have been searching and it looks like if I get the motor high enough I should be able to do it......

Wish me luck!!

77wolf10.85
May 25th, 07, 04:20 PM
Brad, if you were within a hundred miles of me I'd figger a way to drop in there and we'd yank it with my Autocrane. Be out in an hour. You'd throw rocks at cherry pickers from then on. But if I tried to drive to California I think I'd get in trouble.:D

kustomwerker
May 25th, 07, 07:31 PM
if your pan doesnt have a baffle in it, under boost, the oil will fling off the crank throw in the back of the motor(7 and 8) and the pump will pull bubbles, causing the low oil pressure...dump the belt off the blower, and see if the pressure variance is as great as with the blower on...also, does the oil pressure drop when you lay on the woah peddle really hard???if so, i`d think changing the pan will cure your woes...if oil is getting stuck in the heads, a LIGHTER oil will return to the pan faster than 20-50...pop the valve covers, and look for casting flash in the return ports...you can relieve the flash, and increase oil return...

whytry
May 26th, 07, 10:35 AM
Mike, I wish I would have checked this earlier... I tried pulling the pan already and now I am stuck and can't get it off from where its at... It's close but the back of it hits the Mcleod Bellhousing..... But when I hit the pedal, pressure is pretty good but at about 4000 rpm it starts to drop......

kustomwerker
May 26th, 07, 06:30 PM
i get it, but boost comes on prolly at 3800 or so,right???thats when the car starts pullin like stink???also when the pressure drops off???looks like you`re jerkin the trans...that sux cuz there is like a half million bolts holdin that sukr together...try pullin the dist cap to get a little more height on the moter to get the pan off...maybe if you`re careful, you could loosten the bellhousing bolts only, and get a half inch just to bypass the pan...but if you go with a 7 qt pan, you`ll be pullin the motor anyway...sounds like you`re well on your way to figgerin it out anyway, so keep us in the loop...interested in the end results...

whytry
May 29th, 07, 07:59 AM
OK so I should get to fire it up today with the new 7 qt kicked out milodon pan... I had to get new header gaskets.... Got those and will be installing them tonight... Then I should be able to give everybody some feedback on if it solved the problems..

Everett#2390
May 29th, 07, 08:51 AM
Did you happen by chance pull a rod & main bearing cap to see what the bearing shells look like?

mdprovee
Jun 4th, 07, 10:14 AM
Any news Brad, did you get it fixed?

whytry
Jun 4th, 07, 02:22 PM
Sorry guys, helped a friend do some moving and then Pleasanton (went as a spectator). I did get the pan on, all gaskets in and started her up, held good pressure cold start @75 psi, let it sit and get warmed up, pressure went to about 50, began driving around and seemed to increase pressure while driving at cruising speeds, shifting.... Hit WOT in 2nd gear, pressure climbed to 75 psi, and then held steady and then came down to about 45 psi when I shifted into 3rd, (this was normally 10 psi) pressure began to climb up to 75 psi again and then did it again.... Same thing into 4th and then let off in 4th on the freeway....

It looks like it has pressure, finally...

But no I did not pull a main cap or bearing, I got to the point of being so frustrated that once I was able to get the pan in place I left it there and put the gasket on...... Also by this time I forgot too pull one... Now that I have this process down pretty good, based on what I said above what would you guys do next?

Steve69SS396
Jun 4th, 07, 03:37 PM
Brad - Glad to hear it's fixed. Now take it to Sacramento and see what it will do. :beers:

Steve

77wolf10.85
Jun 4th, 07, 03:42 PM
Now that you're good at doing the pan leave the damthing on there. Sounds fixed to me. Glad I was wrong on your bearings.

mdprovee
Jun 6th, 07, 07:22 AM
Glad it was a relative small problem, and you got it fixed.

Very nice car by the way.

whytry
Jun 6th, 07, 07:35 AM
Thanks everybody!!! Glad it was a small problem as well. Now I can actually have some fun driving it.......

kustomwerker
Jun 6th, 07, 06:12 PM
i`m still curious, did the pan have a baffle???just for my own knowledge...we run a procharged 383 with the same pan you got...works great...glad its fixed...

whytry
Jun 7th, 07, 09:27 AM
The old pan did not, it was basically a stock replacement for the motor...