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High Oil Pressure? (7 replies)

tonyr
7 years ago
tonyr 7 years ago

I have just started driving my recently purchased mk3 cooper S and have noticed that the oil pressure is around 100 PSI when I first start the engine and drops

tonyr
7 years ago
tonyr 7 years ago

I have just started driving my recently purchased mk3 cooper S and have noticed that the oil pressure is around 100 PSI when I first start the engine and drops to about 50/40 PSI when the engine is at normal temperature. Is this too high or quite normal.

I did wonder if the oil pressure release value is OK.

ROLI
7 years ago
ROLI 7 years ago

No, its not normal. Should be 75psi at 4000 rpm. You either have a bearing problem or the oil pump is on its way out, most probably its bearing failure...sorry....

tonyr
7 years ago
tonyr 7 years ago

Hi Roli,

Not what I really want to hear but appreciate your help. When you say bearing failure I assume you mean main bearing for the crankshaft. I am a little surprised as the car has only done just over 11,000 miles. What type of damage would you expect to see? Is it worth getting the oil pressure check via a different oil pressure gauge from a garage?

keith
7 years ago
keith 7 years ago

Hi tony.
My mk3 also runs 100psi when cold then drops to around 50psi when warm and the engine is fine.

minicentie
7 years ago
minicentie 7 years ago

You should check the pressure regulating valve just near the oilpressure takeoff on the block.
It's a big bolt about 1 inch with a spring loaded bullet behind. If the former rebuilder /owner has done something wrong it could be there.
On all mini's there is a bullet shaped thing that shut's the pressure untill it reaches it's neede pressure and let seep out the extended oil into the gearbox back.
On cooper 's' this was a ball like one found in bearings about 8 mm big.
If one convert's a bullet to a ball bearing you have to shorten the spring or the pressure it will open is to high ( like what could be your problem).
It's an easy check and can be changed easy.
It would be strange to me ,lik Roli said , if the bearings or whatever in the oilway's would get tyred , the oilpressure would go up?? It would go down in my opinion.

tonyr
7 years ago
tonyr 7 years ago

Hi Keith,

Thanks for your response to my post. I must say that my mk3 is running really well at the moment. I just balanced the carbs this weekend and the engine is ticking over really nice.

keith
7 years ago
keith 7 years ago

just removed my carbs now and overhauling them where abouts are u tony

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