Mornin' forum, been some time since my last post but I need some help once again. My 1997 Bonneville SE naturally aspirated 3.8L started showing a very low oil pressure reading on the dash cluster gauge so I replaced the very bad leaking sensor. At that time I used an oil pressure test gauge to verify the reading on the cluster gauge. The problem I encountered with the test gauge was a rapidly wildly twitching needle. The car has 195.000 miles on it. I just cannot justify putting her down. Love it. Will someone tell me why the test gauge is twitching so?

Thanks,
Russell

Did you replace the bad sender and it still reads low? Use another gauge if you want.

Yes, I did replace the sensor and that stopped the leak and increased the dash gauge pressure reading by about 2# but it was prior to putting in the new one that I used an oil pressure tester. The pressure on that gauge showed the dash gauge to be about 4# lower. My issue is with the test gauge needle twitching. I've read it may be because of bearing wear but I would not think that would cause the needle to be as erratic as it is. I tried to attach a 5 second video of the gauge as the engine is running but I can't figure out how and the instructions I found in the FAQ section didn't work.

Your problem is with the tester you have not the engine.

I just hope I'm that lucky. I bought this tester just for this one use so I couldn't justify spending a lot of money so it'* definitely not professional grade.
Thanks carfixer007 for your input.

How many PSI is the dash gauge reading?

How many PSI is the tester reading, like the low and high of the fluctuation?

At 1800 rpm:

dash = 38
tester = 42

The fluctuation is 10 psi and the needle is just a blur.

That'* fine. My 1997 LeSabre (with the same engine/transmission) is about the same. Over 250,000 miles now and still runs fine.

That'* impressive mileage. I tend to avoid car payments so I take care of them as best I can. Unlike the old days there'* not much you can do. This engine has proven to be very good. Thanks for responding to my post.

Russell