Re: High Oil pressure
 

Did you replace the oil pump? The pressure regulator in the pump may be stuck. Since all this happened after an oil/filter change, I'd replace the filter with the correct OEM filter (Not an after-market) and the proper weight of oil that is listed in your owners manual. 80 psi is totally our of specs. I would check the oil pressure with a hydraulic gauge screwed into where the sending unit is to verify oil press.

Good Luck!

MrBill

Re: High Oil pressure
 

I agree with replacing the oil filter. You may have one not meant for your engine. By the way, for the 4.3 V6 engine, the oil bypass valve is not in the oil pump but rather in the oil filter mount and prevents oil from being blocked by a clogged filter. It does not limit the overall oil pressure but limits the difference in pressure at both ends of the filter to no more than about 15 psi.

Re: High Oil pressure
 

I checked a MerCrusier service manual and all the Mercury engines have the same engine oil pressure spec of 30 - 60 psi except for the 7.4L which is 30-70psi.

MrBill

Re: High Oil pressure
 

I agree with MrBill that you should use a more accurate gauge to determine for sure where your oil pressure numbers are running. Sometimes the sending units can be inaccurate as much as 10 psi.