high oil pressure
 

Hi folks. I just recently got another 7. This one has very low miles (44,000). The oil pressure seems to be much higher than the other 7s that I have had in the past. The pressure runs between 60 and 110 on the stock guage. I would assume that I am running about 85 if the guage is accurate. Is this too high?? Is higher pressure better than low pressure??


Any thoughts,

Bob

1989 GTUs

Could not help but be amused at the factory manual check out of the oil pressure. They have you disconnect the oil sender unit and install a mechanical gauge(Says tons about the accuracy of the stock unit). On a 87 N/A it say the pressure at 3000 should be 64_78 psi. I'd check it with a mechanical gauge.

Yeah...don't trust the factory gauge. Your probably fine, but best to check with a mechanical gauge just to make sure.

I wanna know...
 

...The answer to his question. How high can oil pressure be before is considered "bad". And, what are the effects on the engine, as well as reasons that may cause this...

-Brian

High Pressure
 

Oil pressure is a function of the volumetric output of the oil pump versus the resistance presented by the clearances in the engine. Think of it this way; a worn out set of main bearings would be a "large hole" for the oil to escape from and would therefore lower oil pressure. The flow of oil measured in volume would be the same in either case. A fresh engine with new specs will have higher pressure because of the smaller clearances between the moving parts.

This is the reason racing engines need a high output oil pump. These engines are built with much larger clearances between the bearings, and therefore need the extra volumetric output to maintain a decent pressure. High output oil pumps are of no benefit in a normally built engine.

An engine that suddenly develpos high oil pressure would indicate a serious problem with oil circulation. High oil pressure in and of itself is not a problem if all other things are ok inside (I am speaking of proper clearances here). An engine that suddenly develops higher than normal oil pressure would be indicative of an undesired restriction in the oiling system.