96 BonneSE Oil Press Gauge Red Line & chime
Mileage about 262K

Need help; please advise.

Today While on return 5 mile store trip; a constant chime began and oil pressure cluster gauge Red lined.

Immediately stopped checked oil. Oil about a half a quart low. Oil looked normal; normal color, no foam.

Temp gauge was about 180. Did not see any oil leaking or any steam from the engine.

Coolant bottle had coolant in it; normal color (orange/red). Radiator cap warm to touch did not open.

Let car sit about 15 minutes; cranked it Oil PSI was about 38-40. Two miles to home; drove 1 mile chime came on oil pressure redlined about 18-20 PSI maybe lower. Stopped car and parked it on the street about 1 mile from home; where it currently sits.

Engine sounded ok.

No history of Oil Pressure problem on this car but in Feb 05 I did change the oil sender unit as it was leaking. This oil pressure gauge has always read low about mid 40'* PSI.

Had upper intake changed at dealer at about 160K. Since then I lose about a quart of coolant every 1000 miles.


Please any advise and any suggestions.

Thanks.

Might be a sending unit problem. Check the wires to the sending unit for fray'* etc. Try this test procedure out https://www.gmforum.com/t279651/ to rule out the sending unit.

That sounds like a bad sending unit. If the pressure was low you would hear it. Check the plug for corrosion, clean it up good and give it a try again.

Thank you for the timely input. I am unable to pull up the above link.

I will check for corrosion.

I will probably take a chance and drive it back to the house; 1 mile.

Thanks again.

Prior to a second upper intake manifold failing completely, I experienced coolant loss and low oil pressure. Before it went out completely (turned out it was installed incorrectly by the previous owner), it started blowing white smoke out the tailpipe. Got any white smoke?

If you are loosing coolant with no puddles under the car, it has got to be going somewhere, and with mine, it was into the motor and out the exhaust...

Thanks JB

I also experienced the white smoke on the first upper intake failure. No white smoke currently but assume any coolant loss is also going out the tailpipe.

Update. 96 Bonneville SE 262K

Changed the sending unit thru the passenger side wheel well. My pressure is reading about 38 psi; Temp about 185. Oil PSI is still lower than what it normally reads.

Oil PSI does not really change much on increased RPM.

How tight should the sender unit be? I could not find the reference in my factory manual. What occurs if sender is too tight.

I snugged the sender down pretty good to the point the old was at in reference to the position of the electrical connector; provided I did not tighten it another 360 degree? On the new on BWD sending unit I can see the top of the orange anti-seize compound. ( I used Sender socket w/ 1/2 inch drive)

I could see oil in the valve cover slight pooling; engine running;

On my way to change the oil and filter.

The above testing post has been moved from the testing section and I can not find it? Is the testing procedure still on the board.

Danthurs: The inside of the old sending unit looked pretty clean. Hard to get a good look at the connector face from position. May have to get it on a lift to have good look.

What should the oil pressure be reading? What tool does one use to get a manual reading of the oil pressure?


Thanks everyone for the advice. Please add other suggestions.