LLY: oil pressure sensor

[duramatt05]

got a buddies truck here that i did headgaskets on 2 weeks ago, and he called me up today said his oil pressure gauge dropped to 0 and "low oil pressure" came up in the dic. told him to check the oil, and its still perfect, no leaks anywhere. i know its commun for the stepper motors to go out in the clusters, but while i was searching ive read that if the dic comes up and says low oil pressure, that its not a cluster problem. is it commun for oil pressure sensors to go bad. i cant see the oil pump just quitting. i sure hope not anyway. Is there somewhere simple i can throw in a cheap oil pressure gauge to make sure its not the pump?

 

[AubleAK]

Get a pressure gauge and a hose with the right fitting on the hose, pull one of the plugs from the oil galley and plug it in to read oil pressure.

 

[duramatt05]

changed the oil pressure sensor today, still no oil pressure at the gauge and says "low oil pressure". bought a oil pressure gauge but couldnt find a fitting that would thread into where the sensor goes. so i loosened the banjo bolt off the turbo feed line and pulled the injector fuse, cranked it over and cant get any oil to come out. put the fuse back in fired it up so i would spin over faster and still no oil at the feed line. i know oil pumps are very rare to go out. is there something else that could be wrong?

 

[jc1843]

Sometime the nut holding the pump gear on, will come off, and loose pressure.

 

[duratothemax]

Sometime the nut holding the pump gear on, will come off, and loose pressure.

x2. The nut on the oil pump drive gear is "normal" thread (not reverse), so it IS possible for it to back off, and then the gear just spins on the shaft.

 

[blackdirtymax]

x2. The nut on the oil pump drive gear is "normal" thread (not reverse), so it IS possible for it to back off, and then the gear just spins on the shaft.

X3 also just a helpful hint , if you buy replacement pumps from gm ( or others I suppose ) the new pump comes with reverse threaded shaft to help eliminate this problem.

 

[redws6rocket]

Swap clusters and see, we have a lot more cluster problems then oil pumps.

 

[AubleAK]

X2. It wouldn't take long for that engine to start knocking either if it had 0 oil pressure.

 

[jc1843]

He checked for oil at the turbo-- and had none.

 

[duratothemax]

Swap clusters and see, we have a lot more cluster problems then oil pumps.

Its not the cluster.

If it was the cluster, it wouldnt say "OIL PRESSURE LOW" in the DIC and start dinging at you.......

 

[duratothemax]

X2. It wouldn't take long for that engine to start knocking either if it had 0 oil pressure.

You would be surprised!!! I had a buddy with a high-mileage (200k+) LB7 that had the oil pump gear nut back off. He thought it was the cluster/sensor, so he drove it ~2 miles home.

He changed the sensor and stuff, still no pressure. He pulled the front cover and sure enough the gear was just spinning there and the nut had backed off. He tightened the nut, put a tack of weld on there, put it back together, and drove the truck another 75k miles or so before selling it. Never had another problem.