89 grand prix 2.8l.

**stoney81ta** · 12-08-2008

HI all havent been here for a while,my buddy bought a 89gp with a 2.8l,he is havng a issuse with oil pressure,when he firsts starts it the oil pressure guage goes all the way to the high mark and its takes about a good 20 minutes to level out athe running level.Any ideas why would be great,also the car has 193 kilometers on it now.Thanks all

**SyntheticShield** · 12-08-2008

Most likely the oil pressure sending unit is going bad.

Great car by the way. Exactly the year and engine I had for my last GP and I put nearly 200k miles on it before I sold it and it was still going strong when I did.

**stoney81ta** · 12-09-2008

Thanks Scotty,where would he find the oil sensors and are they easy to replace.

**SyntheticShield** · 12-09-2008

I believe, and its been long time since I owned that car, but I believe the oil pressure sensor was on the front side of the block, facing the radiator, down low just above the oil pan.

I believe it was there with the oil filter, as most are, but dont quote me on that. I wish I could help more but its just be a very long time since I owned that car. Its kinda tight to replace it (I know as I had to replace mine) but not impossible, just have to be patient and take your time.

**stoney81ta** · 12-09-2008

Thanks Scotty

**SyntheticShield** · 12-09-2008

Not a problem, thats what we are here for.

**stoney81ta** · 02-07-2009

Hi guys,what is the proper rpm at idle.Thanks all in advance.

**RareGMFan** · 02-12-2009

When it's cold, around 900 - 1000 RPM. When it's warmed up, around 600 - 800 RPM. And Scotty is dead on about the location of the oil pressure sending unit. They're inexpensive, and removing them is a matter of unplugging the harness, and unscrewing the sending unit out. It's just a bit of a pain due to the lack of adequate working room.

BTW, how'd this end up in the 2.3 Quad4 section?