drdave88

iTrader: (3)

ok, ive heard a lot of stories of GMs always having problems with the oil pres. gauge. i have an 88 v-6 camaro, and its pegged. is the gauge bad or could it be the sending unit? and if it is the gauge, how much of a pain are those to fix?

black89ws6

If the gauge stays pegged when the key is off, I'd say it's the gauge. If it goes to 0 when the key is off, and pegs when the key is on, that *SHOULD* narrow it down to wiring or sender. These gauges operate on a variable resistance, where a high resistance (or open circuit) is 0 psi, and a lower resistance is higher pressure. A short to ground would cause the gauge needle to peg.

I'm not certain that I have that right, I may be backwards on it, but I know the principle is right.

black89ws6

I just looked it up in my book...I had it backwards. higher resistance is higher oil press. If it's pegged even when the engine is not running, there could be an open in the circuit. Check and make sure the sender is plugged in, and that the connections are good.

According to the book ,the sender will read 0 ohms at 0 psi, and 90 ohms at 60 psi. If cleaning the connections doesn't help, put an ohmmeter on the sender output, and check resistance between the sender output and chassis ground. Check it with the engine off, and with it running. If it is the same both times, the sender is probably bad