Questions and Answers

Bonneville Oil Pressure Warning Q. Dear Vincent, I own a 1993 Pontiac Bonneville SSE, 3.8 liter V-6, automatic transmission, with 156,000 miles. While driving home, my oil pressure alarm went off and the gauge read that the oil pressure had dropped to 0. By the time I pulled over, the engine was making a loud, rough rumbling noise.

I had the car towed and serviced (I was told that the oil pump had failed) but ever since the oil pressure gauge indicates 0, rises to a normal level as I accelerate, and then drops back to 0 as I coast or brake. The car runs great, but every time the oil pressure gauge drops the alarm rings, causing an annoying disturbance. Is it likely that this problem is being caused by the oil pressure sender, or should I pay to replace the entire instrument panel, as my Pontiac dealer has suggested I do?

Thanks,
Peter

A. If indeed the pump failed, you may have caused some damage to the bearings and they now have excessive clearance. This would cause the light to come on at idle. The thing to do is to install a mechanical gauge on the oil pressure port to see exactly what the oil pressure is doing. If they say you need a dash, then the oil pressure is not really going to zero, but I'd want to know for sure before I drove it another mile!