low oil pressure

[cedalice]

my 90 ZR1 has only 8900 miles
the car is arrived in europe with 8000 miles in 91 but since 91 only 800 miles.
In 2006 the motor has been rebuilt because there was a lot of water is the tank and when the owner has started the motor there was some damages.
Now the problem is with the oil pressure gauge or may be the oil pressure.
I had a leak from the oil pressure sensor. I have replaced the sensor yesterday.
When the car is cold pressure is around 80 but after 40-50 miles the pressure is low around 0 !!!!!!! but there is no leak under the motor, from the sensor. The oil level is good.
when the oil pressure gauge is around 0 I have no "check gauges" .Before I change the sensor I had this "check gauges" when the car was cold or hot.
All the others gauges are OK oil temp or water temp.
So can you help me ?
and sorry for my english

[BOB HDZ]

http://w39syg.bay.livefilestore.com/...6/IMG_0607.JPG HOPE THIS HELPS

[cedalice]

thanks but it's not the oil temperature but the oil pressure

There are two sensors. One for the ECM which triggers the low oil pressure and will kill the motor. Then a second sensor that sends the data to the gauge.

Check the actual pressure with a mechanical gauge.

[Pete]

Change/replace oil sending unit (the one next to the oil filter) cost $10.

Common LT5 issue/problem.

Pete

[A26B]

As you may know, there are two(2) oil pressure sensors. The sensor that provides the signal to the instrument panel gauge is the large one, on the top near the oil filter.

The other sensor is just for the low oil pressure warning light. It is located below the oil filter, on the oil filter housing, just below the forward, right corner of the cam cover.

If you are not seeing a warning light and do not hear any engine noise (cam chains or lifters), then you probably have oil pressure even though the gauge indicates near zero(0).

I would suggest installing a mechanical, oil pressure gauge (no electronic sender). A "tee" can be installed below the oil pressure sender you replaced. The gauge can be installed permanently or temporarily until you confirm the indicated "drop to zero."

I don't trust the electronic gauge and installed the manual oil pressure guage on the pillar.

[salvatore1]

Originally Posted by A26B

As you may know, there are two(2) oil pressure sensors. The sensor that provides the signal to the instrument panel gauge is the large one, on the top near the oil filter.

The other sensor is just for the low oil pressure warning light. It is located below the oil filter, on the oil filter housing, just below the forward, right corner of the cam cover.

If you are not seeing a warning light and do not hear any engine noise (cam chains or lifters), then you probably have oil pressure even though the gauge indicates near zero(0).

I would suggest installing a mechanical, oil pressure gauge (no electronic sender). A "tee" can be installed below the oil pressure sender you replaced. The gauge can be installed permanently or temporarily until you confirm the indicated "drop to zero."

I don't trust the electronic gauge and installed the manual oil pressure guage on the pillar.

This sensor is the one thats leaking on me. It seems impossible to remove so I cannot even get to it to grab a part number. By any chance do you know the part number for this guy, and do you have any advice on how to get at it?

Thanks,
Sal

Originally Posted by salvatore1

This sensor is the one thats leaking on me. It seems impossible to remove so I cannot even get to it to grab a part number. By any chance do you know the part number for this guy, and do you have any advice on how to get at it?

Thanks,
Sal

25036935

[salvatore1]

Originally Posted by Jeffvette

25036935

Thanks - now to get my hammer.

[Norsky4360]

A GM Master Tech friend of mine told me that the oil pressure gauge sending unit failure was a common problem across the whole GM line back in the late 1980s and early 1990s. Had it happen to us on the 1st day of a 15 day road trip a couple of years ago. He said as long as the oil and water temps were normal and there were no unusal noises coming from the engine we were ok. Replaced the sending unit and haven't had a problem since.