I have a 94 Camaro with the 3.4 ltr. When I first start it up, the oil pressure is about 35-40 at idle. As soon as it gets up to normal operating temperature (about 195) the oil pressure drops down to about 4-5 pounds at idle!! At driving speeds it gets up to around 20. At lights, I have to put it in neutral and keep the RPMs above 1500, or else the oil pressure drops and the engine cuts off.
Oil Pressure DROPS at Operating Temp!!
94 Junkyard Dog
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I have a 94 Camaro with the 3.4 ltr. When I first start it up, the oil pressure is about 35-40 at idle. As soon as it gets up to normal operating temperature (about 195) the oil pressure drops down to about 4-5 pounds at idle!! At driving speeds it gets up to around 20. At lights, I have to put it in neutral and keep the RPMs above 1500, or else the oil pressure drops and the engine cuts off.
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Is it possible you could have spun a cam bearing??
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or bad sending unit?
What weight oil do you have? I built an engine once with .004 clearance on both rods and mains that did the same thing. I knew the clearances were too wide but I was young, to many bills to pay, and used what I had. It ran over 60,000 miles like that.
If you have a light oil in the car now you can put 4 quarts of 15-40 or 20-50 and one quart of Lucas Oil Stabilizer and it should bring the pressure up about 10-15 pounds.
That should be fine in the summer but that combination gets mighty thick in the winter. You can try it and see what happens.
I just guessed your oil capacity is 5 quarts. If it is not let the Lucas be about 20 percent of the mixture.
If you have a light oil in the car now you can put 4 quarts of 15-40 or 20-50 and one quart of Lucas Oil Stabilizer and it should bring the pressure up about 10-15 pounds.
That should be fine in the summer but that combination gets mighty thick in the winter. You can try it and see what happens.
I just guessed your oil capacity is 5 quarts. If it is not let the Lucas be about 20 percent of the mixture.
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Actually, I am using an AC Delco oil filter. I don't know about the spun bearing thing. I do know that the dealership/junkyard where I bought the car about a month ago had the car unregistered since 2001, so it's possible it's been sitting all that time. That's why I was trying to change the oil a few times to flush out whatever might be sitting in there. I will change the oil again tomorrow with the hopes that the filter I have on it now is faulty. I don't know what else to do. I really don't have the time or money to drop the pan and replace the oil pump.
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A friend suggested that I drain the oil and fill it up with a gallon of carb cleaner and leave it sit overnight to dissolve any possible sludge clogging the oil pump screen. I did that and flushed it with some 10W30, then drained that and put in 15W40 oil. I also added BG MOA oil additive to help thicken it up a bit, but didn't see any results after all of that.
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I did put a mechanical gauge on it and unfortunately, the readings are correct. Looks like I have no choice but to open it up (and my wallet). Thanks.
Try 20-50W non synthetic and a WIX or Napa gold oil filter.
I'll bet you see some results then.
My oil pressure starts out cold at 60 to 80 from idle to about 3k rpm. After its warm, it comes right down to 25 at idle. That is with the combo I mentioned above.
With 10-30, it was too low of oil pressure.
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I'll give it a shot today. I hope it works. Is there a way to tell if it's spun a bearing without dropping the pan? Wouldn't that cause much more noticable problems than just low oil pressure?
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I know of lots of engines with 5psi at idle. As long as it increases (10PSI per 1000 RPM), it's fine.
To me, it's a wash. If you have a spun bearing, you're gonna need to rebuild it. If you drive it the way it is until you KNOW you have a spun bearing, you're gonna have to rebuild it too. So why not wait until something goes wrong? Put some thicker oil in there and be done with it.
To me, it's a wash. If you have a spun bearing, you're gonna need to rebuild it. If you drive it the way it is until you KNOW you have a spun bearing, you're gonna have to rebuild it too. So why not wait until something goes wrong? Put some thicker oil in there and be done with it.
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I agree and I am still driving it daily. However, it gets a little annoying when I am at a light or in traffic and I have to keep putting it in neutral and maintain at least 1500 RPMs. Otherwise, the pressure drops too low and the car's computer tries to protect itself by cutting off the fuel pump! So, is the general opinion here leaning toward spun bearing and not the oil pump going bad? Thanks.
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Do NOT do that!
With a really sludgy engine, I've been known to put in a quart of kerosene (along with the normal amount of oil) and let her idle a while, it brakes up the sludge real good, then change the oil a few times to get the kero out of the crankcase...
but that's not your problem.
I'd agree with switching to a heavier wt non synthetic oil, along with a wix or napa filter.
If it were a spun bearing, I would think you might hear a knock, but I haven't read of any mention of a knock.
It could also be a struck or foreign debris in the pressure relief valve on the oil pump, just enough to give 5 PSIG at idle. Either way, not an easy fix for an afternoon of time.
I don't think I'd run the engine with any flush, it might loosen up a whole bunch of crud and plug the oil screen. Kerosene, yes, used it to clean the crankcase.
It could also be a struck or foreign debris in the pressure relief valve on the oil pump, just enough to give 5 PSIG at idle. Either way, not an easy fix for an afternoon of time.
I don't think I'd run the engine with any flush, it might loosen up a whole bunch of crud and plug the oil screen. Kerosene, yes, used it to clean the crankcase.
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Thanks for all the advice and help. I also emailed Pat Goss, from Goss's Garage (a syndicated radio show all about cars). He said it was a given the oil pump would have to be replaced, but he thought there may be some other internal problems as well. Specifically, he said the little carb cleaner trick probably etched my bearings and did way more harm than good. Looks like it's time to rebuild.
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