gbarmore

1980 Vette with original oil pressure sender and gauge. The gauge is bouncing all over the place when revs are over 1500 or so. It swings violently in almost a full sweep.

Wondering if my sender could be bad, or if I just need a new gauge, or both. Any way to test? Pretty sure my oil pressure is just fine.

Thanks!!

7T1vette

While your sending unit might have some issues, the violent movement of the oil pressure gauge needle is most likely due to the wire from the sending unit being broken...usually at the connector that mates with the sending unit. It is just vibrating with motion of the car, and the insulation is probably all that is holding it in place. As the broken ends of the wire make connection, the gauge reads; the connection breaks and the needle swings to full gauge reading. The vibration of the engine alone will cause the needle to swing wildly.

gbarmore

Hmmm, good thinking, I hadn't considered that. I will look it over and see if there's an issue with the wire. A 38 year old sender is probably not ideal either. Just hope the gauge isn't getting damaged by the excessive movement. Thanks!

7T1vette

It's an electrical gauge, so not a lot of mass or moving parts involved. You might want to pull the sender wire off until you can work on it, just to minimize any risk of damage.

C7-Beast

I have a similar issue with my 80. When I start the car, the oil pressure gauge stays pegged all the way up then will bounce from 40 and again be pegged once warm.

New sender, no issue with the wire. That's the only gauge that is not working right. Even my clock works after sitting for 15 years.

7T1vette

If the gauge 'moves' to full scale when you start the car, you DO NOT nave a gauge problem. You DO have a sender and/or wiring problem.

Believe it, or not....

Antz81

My 81 has a very similar issue. I've tracked it down to a connection issue at the plug in the firewall. Think it may be on the dash side. Have been able to solve it other than that. No high on my priorities for the car right now.

DUB

Glad that you are looking into it and going to spend time to fix this.

What amazes me is how many people will drive their Corvette with an oil pressure gauge not working properly...or a coolant temp gauge not working.

Because. YES I have had people actually drive their Corvette to my shop with a rod knock and when they cranked it and there was no oil pressure showing on that gauge. They told me it has not worked for a while. And this 'noise' just started earlier that same day.

Can we say.."New engine". Because that is what it would take to fix that engine. Or at lest have it inspected and see if it can be rebuilt.

Do not get me started on the engines that come in so HOT that I can cook bacon on them and it can be seen from a satellite with thermal imagery due to the temp gauge not working.

Come on people...fix your stuff. Or pay the price later when it detonates or goes through a melt down.

DUB

Antz81

I will be sorting mine at some point in the near future hopefully. Fortunately for me it works fine whenever I depress the clutch. So I can still check the pressure at times. They guy I got the car off was a different story. The oil temperature gauge wasn't working, when I looked into it the only problem was that the gauge wasn't plugged in. That and a long list of other problems.

the papster

on my 75 vet the oil pressure gauge stays tacked out at 80 unplugged the sending unit ,still says at 80 even when ignition is turned off

Antz81

Ground the wire at the sending unit, if it tacks out at zero then you need a new sender. If not then you have a break in the wire somewhere