Can anyone tell me what the normal oil pressure should be? I have fitted an aftermarket guage and it reads 30psi on tickover when warm but goes to 100psi when reved to about 4k and above which is as high as it will read. The reason for asking is that I have an oil leak from what appears to be the rear crank oil seal which I replaced when carrying out a manual conversion not many miles ago. If the car is left ticking over, it doesnt leak however when I drive it or rev it high, the rear crank seal leaks. The oil then goes all over the gearbox, exhaust etc. Is 100psi normal as I dont want to go through replacing the rear oil seal again if it wont cure the problem? Any help apreciated. Car is a 1989 twin turbo.

My aftermarket oil pressure gauge reads at just over 100psi and reads 30psi when warm and idle, when the weather was really hot recently I only got 70-85psi when first started up in the afternoon, can't really comment on the 4k revs as I don't drive like that but it Doe's shoot up when booting it.

100psi is way too high. Is this with cold thick oil? Normal should be somewhere 50-70psi at 3000rpm and anything around 20psi plus is good at hot idle. Maybe the aftermarket one is not accurate.

 

The pressure releif valve shoule limit it or seals can be pushed out

Where is the pressure relief valve, I thought they were to bypass the oil filter if it gets blocked? The filter is brand new, the oil and filter have been changed probably three times in the last 1000 miles for one reason or another. Does anyone else have oil pressure like this? Cheers.

Am not sure what the real values should be, but after having my engine rebuilt by jimmer :bow: my oil pressure is 1-1.5 bar at idle, 2.5 bar normal driving, and 3-3.5 almost 4 bar when full throttle and revs.

 

HTH.

 

Al.

Can anyone tell me what the normal oil pressure should be? I have fitted an aftermarket guage and it reads 30psi on tickover when warm but goes to 100psi when reved to about 4k and above which is as high as it will read. The reason for asking is that I have an oil leak from what appears to be the rear crank oil seal which I replaced when carrying out a manual conversion not many miles ago. If the car is left ticking over, it doesnt leak however when I drive it or rev it high, the rear crank seal leaks. The oil then goes all over the gearbox, exhaust etc. Is 100psi normal as I dont want to go through replacing the rear oil seal again if it wont cure the problem? Any help apreciated. Car is a 1989 twin turbo.

Its more than likely your gauge is not 100% accurate.Oil pressure should not affect your seals.The only force exerted on them is crank case pressure.So a leaking rear main will have no bearing whatsoever on oil pressure unless of course you run out of oil.

Thats what I thought but it only leaks when I rev the engine or drive the car. If its just left idling it doesnt leak. PCV valves, pipes etc are all newish so no problems there, perhaps I damaged the rear oil seal when fitting it, looks like the gearbox is coming out again

which may point to a stuck pcv valve

Would a stuck pcv not cause other problems i.e. low boost pressure etc as there are no other symtoms? Boost pressure is fine.

Blocked breathers? Could be causing a high crank case pressure?