My 2000 Bonneville SLE has been reading 120 psi on the oil pressure gage for quite some time. When the engine is turned off it drops down but jumps to 120 psi when it starts up and stays there. does not seem to be using any oil and no performance problems. Any idea of what may be going on?

Bad gage?

Unplug the oil pressure sender. If it'* the same you most likely have a bad sender.

My 2000 SSEi did the same thing last week. I replaced the sender, which is mounted above the oil filter on the filter adapter; and it now works fine. It took a large crescent wrench and a few rags and it was replaced in about 15 minutes.

Kevin, do you know which part number, beacuse there are a few to pick from on rockauto, some say with gauge and things, is the best plan just to go to the dealership?

I got the switch at Autozone. it'* a Duralast P5421, which is for cars with gauges.

*** The actual part number is PS421...my receipt was hard to read and obviously the '*' looked like a '5'. ***

***Moved to Mechanical***

Thanks Kevin

Just wanted to say if anyone needs this part it is PS421, typo on Kevins part lol

got it for $37.99 at Autozone

I was reading it off a receipt and it was hard to read. I can see where a an * looks like a 5...my apologies. I'll edit my post so there is no confusion in the future.

Friggin getting old and having bad eyes is not for the weak or timid!

I think we can forgive him this time lol, I walked into Autozone and go ok I need Durlaast part number P5421 so the guy at the counter is looking and looking some more and finally asks someone else and looked it up in the computer

anyways I can't wait to put this new one in beacuse mine has been broken since early winter, running Seafoam through the engine and an oil change obviously, any tips for where to put the Seafoam for max cleaning?