Hello, I just had the motor replaced in my 1994 Bonneville, and now the oil pressure is pegged at 120psi, and doesn't come down at all when the car is warmed up. Is this bad? What could it be?

Thanks in advance for your help.

Bad oil pressure sender? Any chance of getting a mechanical oil pressure gage on there?

The new motor may have the wrong style sending unit.

Pretty common, should be a bad sensor.

I'll go with the bad sensor on this one. 99% of the time, that'* the issue with high pressure. It'* easy and cheap enough with those odds to just replace it. It'* sticking out the back side of the engine on the passenger side just above the oil filter adapter.

my 96 SSE had this all the time. Changed the sensor. Still did it. After a real good oil system clean took care of the problem. I don't remember what the guy did but, man, did it help.

P.*. your pressure never really actually will get to 120 psi. It'* like the fuel gauges on just about every GM I've owned except the two bonnies. Its a kind of a sort of maybe a target more than an accurate read. Both my GP'* had terrible fuel gauges and the 91 GP never read the correct water temp.

TwoB'*..

Sounds like your car may have had a sticky pressure relief spring or other little metal (I don't know the name) part.

BillB, does sound that way. Would a chemical flush un-stickify it?

Replacing the inexpensive sensor would fix it. Chemicals wouldn't really figure into the solution.