I have an '88 GTA with digital dash. When I bought it I was told that the oil pressure guage didn't work. I discovered, however, that the guage would come up one LED bar off of zero at about 4000 RPM. So, I start hoping that the sender is week and that the digital dash doesn't need to be replaced which is quite expensive. I took it to a local (but good) shop and had the sender replaced. After that the guage would come off of zero at about 2000 RPM. I took it back and reported the change. The shop decided to try a "Real GM" sender to see if that would help. It did, somewhat. Now, when cruising at 65MPH, the oil pressure guage will slowly fluctuate between almost zero and about 30 PSI. However, if you crack the throttle at all, it will drop to zero (which causes it to beep, which is very annoying!) City driving is very annoying since it is constantly beeping at me.

So, here's the question: Is it the digital dash? Is there anything else I should check first?

Yes, it does have oil pressure. Two shops have hooked up a guage and checked it and reported very good pressure. Also, I've been driving it this way for about 4000 Miles so it must have some pressure.

-Farren

 

Good luck with this one. Just when this board went down, I had a digital dash problem. I posted everwhere else & had no takers.
Anyhow, I paraphrase, the 88 GM manual relative to oil pressure gage on DD.
Oil pressure reads zero. Cutting to the chase here....disconnect wire from sendor, gage should show high oil pressure, if so replace sender. Next. if gauge still reads low with sendor disconnected, check for short in Tan wire (circuit 31) between sender & instrument cluster. If wire is not shorted to ground, replace cluster.
Next catergory: Oil pressure display inaccurate...you need to disconnect lead from sender & install various resistors between the wire & ground. 0 ohms = 0psi, 43 ohms = 30 psi, 90 ohms = 60 psi... If display is not correct, check same Tan wire mentioned above for resistance...should not be greater than 1 ohm, if OK replace DD.
If it gets down to the DD, I don't think you can get anything new from GM anymore. Instead, ask a GM dealer where they take them to be serviced. BTW removing the DD instrument cluster is a alot of laughs. Be very patient if you decide to do it yourself.
Regards, FJK