Sassy Kat

Hi everyone 👋 I'm new and have been reading through the site and very much enjoying the site.
My Tahoe has never really had good oil pressure so my son decided it was time to replace the oil pump because I'm about to go loony with the binging noise it is making. The new pump has not helped at all, still no oil pressure and the binging to let me know i don't have pressure. Does anyone else have or had this issue? I'm going crazy. Please help me soon. Thanks in advance.

TXBowtie

Welcome to the LS tick club! New oil pump and still no oil pressure? sounds like you have a bad o-ring on your oil pickup tube. ITs a PITA for such a simple part but my guess is that's your problem.

Gumby22

If you’re relying on the gauge in the instrument cluster for an accurate reading, don’t. Besides not having a direct connection to the oil pressure sensor (signal is data fed from the PCM), the GM clusters of this era are known for problems as a result of cold solder joints and bad stepper motors. The oil pressure sensors are also known for failing.

The oil pressure needs to be checked with a mechanical gauge at the sensor port for an accurate reading. 10 PSI per 1,000 RPM is the rule of thumb.

To test the gauge in the cluster and related circuits (see diagram below for clarification) -

1) Disconnect the oil pressure sensor (top rear of engine behind intake manifold - I’d recommend a good work light and small mirror as needed).

2) With the key on, engine off and the sensor disconnected, the dash gauge should be at zero.

3) Key on, engine off, jumper the tan/white wire to the gray wire - dash gauge should max out.

4) If the gauge doesn’t max out when jumping the wires, check for about 5 volts on the gray wire and 0.02 volts on the black wire. Less than 4.5 volts on the gray wire indicates high resistance on the reference circuit from the PCM.

If the circuits and dash gauge operation check out, replace the oil pressure sensor. There is a sensor specific socket for them, but a 1-1/16” socket with flex extension or u-joint or crow foot type wrench can be used to remove them. Working room is tight but a little patience makes it tolerable.

repairman54

Don't' forget to check/replace the filter screen under the oil pressure sensor, they plug up also.

cctwb

Wow, great and simple answer to understand. Looking for help with something similar and stumbled on this one. Are you still around?

Gumby22

Is who still around?