high oil pressure

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Mon 13 Aug 2001 16:50
high oil pressure - yves cervero
A month ago I noticed that the oil gage pressure on my 89 Chevrolet Camaro RS 2.8 was running very high (round 80 -instead of 40/50) I immediately stopped the engine, checked the oil only to see that smoke came out of the dipstick column for over a minute. I added 1.5 litre of oil but this did not solve the problem.
The oil pressure is still high when I drive it around (very rarely these days) and there is still smoke coming out of the same area, although less than before, perhaps because the oil level is adequate.
I'll add that the car is not overheating and that there's no oil leak although the car does consume its fair amount of oil.
I recently took it to a local garage who told me that the pistons were worn out, that there was too much back pressure and that basically the engine was on its way out. I find it hard to believe that given the type of engine and it's only done 55 000 miles. They added that it would cost £2000 to fix it...
I am at a loss to know what to do really as it is very hard to get advice for american cars from local garages. I suspect it's far less serious that I've been told, maybe something to do with the breathers in the system. What do you think the problem is likely to be and is it safe for me to use for the time being for short distances ?
Thanks a lot for helping.
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Mon 13 Aug 2001 17:09
Re: high oil pressure - Michael
I would check the oil pump pressure relief valve to ensure it is not stuck in the closed position (it opens and closes to maintain the pressure at the normal 40/50) If it sticks the pressure will rise and could force oil past seals.

Did the garage check the pistons with a compression tester or was it a comment based on oil from the dipstick column? Check the compression if they didn't.
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Mon 13 Aug 2001 17:23
Re: high oil pressure - mike harvey
I agree with Michael, check the pressure relief valve. It seems you are giving symptoms for two different faults;excessive oil pressure, and excessive crankcase pressure. The two are not connected. Excessive crankcase pressure is usually caused by combustion gasses escaping down the side of the pistons due to excessive wear in the bore, pistons or piston rings. Also rings can stick in the pistons, causing poor sealing, and some people swear by Wynns, STP, Red-Ex and other such treatments in freeing off stuck rings. Worth a try before you stump up £2000! As Michael says, try a compression test, though really you need comparable figures to make much sense, unless it is just one or two that are faulty. As a guide, you would expect around 150-200 psi. A cylinder leakage test may be more useful, as that would identify the source of the leak, and a compression test would not.
regards
Mike
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Mon 13 Aug 2001 17:39
Re: high oil pressure - Andy Bairsto
Having run camaros and trans ams for twenty years your first port of call is the oil pressure relief valve.This engine was not the best to come out of GM but basically bullit proof have a compresion test done as a matter of course another posibility is the oil breather pipe is blocked.After running for afew miles take the oil cap of if you think there is pressure in the rocker box it will show here .If the worst comes to worst and the motor is worn they can be rebuilt for very little cost.Use the webb there are some brilliant american webb
sites devoted to f body cars.
good luck Andy Bairsto
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