My dad'* 1994 bonneville ssei is have very eratic oil pressure. He says it'* getting really close to the red zone. What can be some causes of a very low oil pressure like that? Can it be an oil filter? I know it could be a bigger problem than that but i just want to see the little things. Okay any ideas would be awsome. Thanks.

High oil pressure means there'* a restriction somewhere in the system. If you're lucky it could be a filter issue. Check to make sure it'* the right filter for the car. I use mostly Fram filters and it calls for a Fram PH3387A but I use a Fram PH3980. If the filter on your dad'* car doesn't cross reference either these, that could cause strange oil pressure. You could check to see if someone installed an oil cooler. If so, make sure one of the lines aren't kinked.

What do you mean when you say erratic. This brings back memories that I JUST fixed. To me it means when I picked up my car and the oil press needle was all over the place...about 40, 120, 80, 40, 120. worse than a fish floppin around outta water.

The only true way to find out if you have crazy oil pressure is to pull out the sending unit (near oil filter on my 95) and test with a mechanical gauge. I bought the sending unit figuring it was the sender. Never took it out of the package after reading up in techinfo about gauge problems with these clusters. Do any of your other gauges near the oil pressure gauge seem to be off as well?

If yes you probably have a bad cluster. If only the three gauges water temp, oil press and alt/boost are acting weird you can follow techinfo article to remove and clean/reseat the circuit boards. Or change the one amsll circuit board (confirmed this last night) that plugs directly onto the gauge posts for those three gauges. Or you could change the entire cluster.

If your other gauges are reading properly I would check the sending unit first. It'* pretty cheap and easy to replace. The chance your pressure is just really high due to a clog is not common, but don't rule anything out.

My dad'* car oil pressure goes very low. The red Zone is the danger zone where your not getting enough pressure to lubricate the engine.

As for high oil pressure. And erratic oil pressure. I have a 1994 ssei as well and on the high way i get the most eratic oil pressure. Goes from about the middle all the way to the max and above then goes down then comes up then down and just acts crazy like that. It'* been happening everytime i take it out onto the highway and for about 8months now. It just jumps up and down like that. And then when im driving around in the city the problem doesnt occur. Any ideas what that could be? Sending unit maybe?

I'd probably take the first stab at the sender. Odd it'* only a higher speeds... sounds electrical and goofy. Just like a Bonnie