Oil Pressure Gauge Wierdness

[webini]

My 87 coupe exhibited new behavior starting last night. The oil pressure gauge reads a steady "3" when the car is in gear, no matter what the revs are. When I take the car out of gear the gauge stays at "3" for a second or two and then drops to just above "1" and fluctuates slightly.

Reving the engine while in neutral gives the result - no higher than "3".

Previously the pressure would range from "3" to between "4" and "5" depending on revs. The car has never leaked a drop and the engine runs like a bear. Had a leakdown and compression check 2,000 miles ago - no issues.

I think the problem is in gauge or sender. Opinions before I go rooting around? Thanks!

[Quicksilver]

If you disconnect the sender then it should go to 5. If it doesn't then you know the sender isn't the problem. If it didn't go to 5 then the next step is disconnect the sender wire at the gauge. If it still doesn't go to 5 then the gauge is the problem. If it does go to 5 then the wire to the sender is the problem.

Wayne

[webini]

Thanks. Dumb question, but where do I find the sender and the wire connection?

[steven polaski]

Look to the right of the fan and under the left hand side of your a/c unit. You will see a two senders, one large one pointing up ( the one you want ) and one pointing towards the back of the car ( idiot light ) Pull lead straight up turn car on and see what your pressure is. I belive the wire is green/red with round funky connector.

[webini]

Thank you!

[Drdogface]

Just had the exact same problem with my 78 SC. It was the sender. Had that replaced and it now works perfectly. I'm betting that's your problem.

Mark

[webini]

Originally posted by Drdogface
Just had the exact same problem with my 78 SC. It was the sender. Had that replaced and it now works perfectly. I'm betting that's your problem.

Hope so. It will be a couple days before I can check it out.

How involved was replacing the sender?

[Drdogface]

I don't think it's a big deal. Pelican sells the sender and sealing ring that needs to be replaced with it. I had a wrench do it because my AC was in the way but since took that out cuz it was shot. At the same time I also had the temp gauge chaged out to one with numbers instead of just a range. Not sure if your's is the same kind. If you don't already have Wayne's book..."101 Projects..." you should order it. Will help in things like this.

Mark

[Argo]

Replacing the sender yourself is not too hard but you should do some research first (i.e. do a search here). Basically there's 2 ways to do it: the fast/easy way with a risk of ruining the case or the slower/harder way with little risk. You'll know what I mean after doing a search. I did it the slower/harder way with no problems. Do quicksilvers' tests first and make sure the wire is making a good connection before you replace the sender.

Argo
88 Targa

[webini]

And then tonight when I start the car to go home the gauge is working totally normally. I had not had a chance to run the diagnostic procedure recommended.

I guess I'll just keep an eye on it.