Susiemaccorvette

1986 C4 corvette was left unstarted in garage for 4 years. After replacing oil and oil filter and battery, tried to start engine.
Engine started, but oil pressure reads 400!

Any suggestions, please?

billschroeder5842

Try to clean the contacts on oil pressure sending unit. After four years it could be pretty dirty and corroded.

If that does nothing you may need a new sending unit as it could be clogged

vader86

The in-car gauge maxes out at 80psi, if its reading 400 I'd say some wiring issues exist somewhere besides the sending unit.

Check with a mechanical gauge to be sure though, you dont want to be wrong on this one.

Benny42

Is the cluster in the metric position? 400 kilo pascals is about 60 psi. Thats normal oil pressure.

Susiemaccorvette

Thanks Vader,
Do you mean the pressure switch maxes out at 80 lbs (high limit), the digital dash led indicator as mentioned showed 400. And do you know if the pressure switch is the one at the base of the distributor, or the switch on the passengers side head? I believe one sends the pressure reading to the digital gauge, and the other is inline with the fuel pump to provide safety for the ECM.
Thanks Susiemac

Susiemaccorvette

Hi Benny!!!
By Jove, you may just be right!! Someone must have moved the switch to "Metric" (darn mice in the garage!!) :0)
It's late now, but we're anxious to start her up tomorrow morning, fingers crossed, it's the answer.

Now, how about those winning lottery ticket numbers?? All kidding aside, thank you very very much.
Big sigh of relief, if this is the solution.

Susiemaccorvette

Hi again Vader, I've just seen Benny42's reply and my "English/Metric" switch on the dash, was in fact switched to "metric".
We'll see tomorrow if this is in fact the source of our oil pressure woes. Thank you very much for responding so quickly. Greatly appreciated.
Susiemac

RtStuf

Excellent - outstanding - good call!

65Z01

Oil pressure sender is on the side of the stalk with one wire, oil pressure sw is on the top of the stalk with 2 wires.
This assy is to the left of the distributer.