oil pressure reading

[garllo]

Ok folks , I have a question. Took my '98 coupe for a ride Saturday and while shifting at around 3500Rpm I noticed the oil pressure at 80#. I switched to the reading on the DIC which was the same. With the key on and the engine off it reads 30#. Sound like a sending switch??

[c4c5specialist]

HI there,

If it rises and falls with RPM, its possble it is normal.

If it was the sending unit, you would see 128 indicated on the digital display.

Allthebest, c4c5

[garllo]

Pressure does rise and fall w/rpm but why would it suddenly change? And why would it now read 30lbs with the engine off?? What would the indication be that it was not safe to run?

[c4c5specialist]

HI there,

If it was reading 0, or less than 6 psi at idle.

Is it possible that the brand of oil was changed ????

Or a different weight of oil was used ????

The sensor might be off as far as pressure, but if your using different oil or weight than what was used in the past, this could be the case..

Allthebest, c4c5

[garllo]

Originally Posted by c4c5specialist

HI there,

If it was reading 0, or less than 6 psi at idle.

Is it possible that the brand of oil was changed ????

Or a different weight of oil was used ????

The sensor might be off as far as pressure, but if your using different oil or weight than what was used in the past, this could be the case..

Allthebest, c4c5

Still Mobil1 w/ AC filter. The Chevrolet dealer changed it this time so unless they switched Viscosity it should be 5w-30. As long as it's ok to drive then I'm not too worried. Thanks again!

[LLC5]

Originally Posted by garllo

Pressure does rise and fall w/rpm but why would it suddenly change? And why would it now read 30lbs with the engine off?? What would the indication be that it was not safe to run?

Your gauge should not be reading 30# with the key on and engine off. It sounds like a sending unit or harness problem. Try checking the engine harness by the left rear valve cover and follow it to the sender, looking for any cuts or abrasions on the harness. If you can, disconnect the sender and see if the gauge goes to zero with the key on and engine off, as a test. Good luck with it.

[Junkman]

A engine cannot make oil pressure if it isn't running. That's the sending unit going south - common C5 issue.

Here's your thread

Here's your thread

.

[garllo]

Originally Posted by Junkman

A engine cannot make oil pressure if it isn't running. That's the sending unit going south - common C5 issue. Here's your thread.

Nice job of documenting that relocation!

[ALMSGT1]

Junkman:
Thank you. That is one of the best write-ups I have ever read. Great job!

[Junkman]

You're welcome gents. If I have to fix it, I'm doing a writeup. Mainly because when I have to fix it again, I don't want to have to figure it out a second time! I use my own writeup when necessary. :)