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327 getting hot very quickly

8K views 22 replies 10 participants last post by  Everett#2390 
#1 ·
I have searched the forum for related posts and found alot on head gaskets, cracked heads, vapor out the tailpipe etc, but still feel like I am not finding info particular to my situation, which is:

I have a mild 327 in my 68 Camaro. I bought it from a friend of a friend, so I dont know much about it. It has 283 power pak heads, performer intake with Summit 600 carb and headers with an m21 and looked to have been recently rebuilt. Its been in the car about 2 years now, and I drive it a few times a week to work (about 10 miles) and take the kids to get ice cream and such. Its a fun cruiser, and the few times I have gotten "on it" have rarely been over 3500rpm. I have a BeCool aluminum radiator with an aluminum shroud and dual electric fans with a toggle switch. No a/c, no power steering, just an alternator.
Up untill a couple weeks ago, no running hot issues at all- even through the hellish phoenix summers. It would run around 180ish and when it creeped up I would flip the fans on and it would stay around 185ish.
Now, when I start it up, after idling for 3-5min, the temp gauge quickly rises to 180deg. Took it for a "spirited" trip around the block, and the temp is up to 200deg. Pull into the driveway, shut it down and the temp creeps up to about 230deg and its puking out the overflow hose. The hoses are rock hard and very hot to touch. I am running a water/antifreeze combo.
Observations:
I did notice that the drivers side tailpipe has alot of black vapor (one of my forum searches for that) dripping out of it when I start it up- the pass side not so much. It didnt always do that.
It runs great- lots of power (for what it is), no mis- firing, sounds great.

I did replace the thermostat with a 180deg one, and added some purple ice, after the initial hot run a few weeks ago, but nothing changed.
So, now I am worried- cracked head, block, blown head gasket...
I checked the head bolts last night but they were all right at 65lb ft, so...
Could it possibly be the water pump? I hate to start chasing my tail and start replacing things that may be ok.
So, thats why I am here. This group has never disapointed me with their knowledge.

Sorry for the long post- wanted to make sure you had all the info you needed.

Thanks in advance for the replies- its finally cruising weather in Phoenix and I need my baby to be ready...

Dean in AZ
 
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#2 ·
Is the temp. 'Stable' at 180-deg. at idle and low speed cruising?
If you remove the cap - prior to start up and idle to temp.! - can you see circulation from the tubes to the into the suction side of the radiator tank?
Is there a Spring in the lower hose? (you can try squeezing the lower hose, when cold!, and see if it gives resistance) and does it show signs of collapsing (with cap back on and system at idle temp.) when you raise the trottle to higher RPM range?

And - how are the Fan(s) controlled?
Manual or auto switch?
Are they 'Pull' or 'Push' ?
What type of electrical feed - direct or relay system?
Have you read voltage at fan(s)?
With other accessories requiring 'cooling' I take it there is nothing in front of the radiator itself?

Those will give a start to looking for this type of issue ...
 
#3 ·
Prior to two weeks ago, the temp was stable at 180 yes. If I sat in traffic it would start to go up, but then I would turn the fans on and it would hover around 185ish. Now, however, as soon as I start driving it, the temp keeps going up past 185 to 200 and so on. In the past, the only time I really needed the fans was at 3-4pm in the summer when its 112 degrees outside.
I will check the circulation this evening. the lower hose does not have a separate spring like they used to no. I will check for collapsing this evening as well.
Fans are manual switch, pull through, direct feed- no relay. Nothing in front of radiator.


When I used to take it to work, I would usually be half way home by the time it got to 180, now its almost instantaneous.
 
#4 ·
Odd. Not sure what to tell you.

You didn't bump the timing by accident did you? Have you checked the timing?

Usually when a water pump fails, it will leak. Have you noticed any water dripping from the water pump area?

Have you noticed a loss of coolant?

What does the oil on the dipstick look like? Normal or does it look "milky"?
 
#5 ·
Nope- I didnt mess with timing. I will check it tonight JIC, but it would have had to have done it on its own- loose dizzy bracket or something. Like I said it runs great- no missing, good power, etc.
The only loss of coolant that I can tell has been from the puking after a drive.
I will check the oil tonight as well.

Do water pumps make any death noises before they go? heard a rattling last few trips out before the problems started- thought it was my clutch, but no rattling now- could be a coincidence
 
#7 ·
And sorry, this may sound stupid, but you DID verify that the cooling fans are both turning when you have them on - right? Hate to overlook the obvious like maybe a blown fuse or relay.
 
#8 ·
Good suggestions by all - start with the simple stuff. Check the rubber line going from the carb to the vacuum advance on the dizzy to make sure that did not come off, cracked, etc - that extra timing at idle helps with cooling.
 
#10 ·
Sounds like head gasket to me. A quick trip to a shop with an analyzer can check for combustion gases in the coolant. Or do a leakdown test.
 
#12 ·
Ok- got home late last night from work, so I didnt check the timing, but the vacuum hose was on on and it was tight. Dizzy clamp was tight, so dont think timing has been affected.
Lower hose does not appear to have a spring in it and when I put the car together I remember there not being a spring and searching this site for clarification on that.
Started the car and got up to 180- couldnt tell if the coolant was moving or not, but at 190 the coolant level was high enough to start leaking out the overflow hose. No bubbles.
Checked the dipstick- nice clean oil- not milky.
Water pump not leaking and no wobble.

Last evening was actually pretty nice here- probably high 80’s low 90’s- so not hot at all

Here is the blow by blow after checking the above items:

Idling fans off
5min
Cap off 190deg
Pushing water out overflow hose

Idling fans off
7min
Cap on 200deg
Lower hose hot
Upper hose cool

Idling fans off
10min
Cap on 230deg
Lower hose hotter
Upper hose warm
Turn fans on- instantly temp goes down to 190

Quick spirited trip around block- fans off
As the rpm goes up so does the temp to 230.

Same quick spirited trip- fans on
RPMs go up but temp stays at 190.
Shut down- temp hovers 210-215- engine off, fans off.
No puking.

On the two trips around the block, noticed oil pressure drops off to around 20psi.
Had initial break in issues two years ago and buggered something up- main bearing possibly, and the op has been low since. Running strait 50wt oil presently. I had mentioned the ringing noise before, thinking it was the water pump- could a bearing have finally let go, and the added friction be driving the temps up? The car still runs great and the power etc, but just thinking outside the box here.

So, what do you think? Head gasket, bearing failure…
 
#17 ·
your upper hose should be HOT and the lower cooler, yours is the opposite and that is telling me your rad is not doing its job or you dont have a shroud on the rad? if not you need one. one more mistake I have seeing is people installing serpentine belt style water pumps on the old style pulleys and those pumps spin the other way
 
#14 ·
1st - it's normal for the engine to rise once the engine (and fan(s)) are shut down there's a lot of 'soaked heat' in there still that has to dissipate over time. It's the reason some newer cars actually run the electric fan(s) for a length of time after you shut the vehicle down.

So your problem seems to be from lack of heat transfer from the radiator to surrounding air to allow proper cooling performance.
This could be due to;
* need for air circulation from the fan(s) system
* problem with radiator sizing or heat transfer

Is there a reason you don't have the fan system on an automatic temperature controlled circuit?

Also, and I know this is a weird question, are you sure the thermostat is actually the rating stated and it is installed correctly?
Did you notice if it had a Circulation Hole in the unit to allow a small by-pass of coolant to help with warm-up and prevent any air-lock issues? If not, you can drill a small hole.
I have been drilling 1~2 1/8" or so holes in every thermostat I've installed for something over 40+ years now ...
Will look like this - Auto part Wheel

You don't have to go overboard like the Ford guys do :noway: - Auto part Circle Wheel Metal


I would also encourage you to allow the vehicle to get to operating temp and then raise the throttle while observing the Lower hose - you can usually see signs of it starting to collapse at mid-range throttle speeds.

Last quick stop would be to stop by a local radiator shop and have them run a quick test of the system for combustion gasses.
You can also rent the kit from AutoZoned and other parts stores and do it at home yourself ;)
Scotty here can show you how -

Oh, and I wouldn't be worried about oil pressure or bearings at this point.
If a bearing was really bad you'd hear it and there wouldn't be enough 'friction' to heat the oil - or you'd REALLY hear it ...
A drop in pressure is normal as engine temp. increases.
 
#15 ·
John,
Thanks for the reply. I will check the hose again tonight and get the test kit from AutoZone.
Pretty sure I installed the thermostat correctly, but unsure about the hole. I will check.
No relay on the fans was for simplicity of wiring, nothing more.

I'll let you know what I find. probably be early next week before posting

Thanks again.
Dean
 
#16 ·
You can check your plugs for signs of burned coolant or oil . Rent or borrow a radiator preasure tester and install cold, start engine and check guage on tester. You'll know if it's a head problem. You said you couldn't see the coolant circulating, try lowering the level and checking. That sound may have been the fan in the water pump coming off the shaft. Also may check the thermostat again for orientation or contamination. Check the oil for metal. Shaft bearings will knock, squeel, or stop the engine. the lowered oil pressure is probably from the heat and viscosity break down. I wouldn't drive it to work. Hope you get it
 
#19 ·
I had the same problem. The result of mine, twice, was an eventual spun bearing. I finally set that engine aside and am in the process of installing a crate engine. I am going to try a different machine shop next time and give it another go in a year or so. I'm curious to hear what you determine the problem to be....
 
#20 ·
I rented the radiator test kit from Autozone- looked a little different then the one Scotty demo'd but same principle. The instructions were a little different too, but I followed them and the liquid stayed blue.
I am going to take the car in next week and have it anylized at the shop.
I did get the temp back up and did some throttle manipulation, but I couldnt get the lower hose to collapse at all.
No serpentine system- single belt to the alternator. Aluminum shroud with dual fans.
Will check the thermostat this weekend and drill holes if needed. Also will check plugs for coolant/ oil.
Otherwise, I will have to see what the shop says next week.

I will let you know what they find.

Thanks again for all the input- this is a head scratcher for sure...
 
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