GM Tech...2005 Duramax low oil pressure.
 

I'm looking at a 2005 150,000 Duramax. The oil pressure barely gets above the red line at idle. Maybe 2 bars above at 1500 RPM. No low oil light comes on and no alarms. I did some searching on the Internet and get some conflicting views. Some say the LLY engine has a LPHV pump and is normal. Opinions please.

my 2007 LBZ with 90K ran low below 1500 rpm.

I guess I need to get a mechanical gauge on it. Apparently the stepper motor on the gauge goes out.

I had a GM truck that had a couple bad stepper motors and the affected gauge did not work at all. I would put a mechanical gauge on it and check what it says. I have had LBZ and LMM DMAX trucks and both have more oil pressure than the truck in question at all times.

had a 05 before my 08, neither showed much OP at idle...never had a issue

My '04.5 LLY showed good oil pressure even at idle. !5W40 Rotella. I traded it at 50K miles so not sure if that would have changed with more miles. .

Let's try this.

http://s43.photobucket.com/user/jay2...35321.mp4.html

Check out these gauges from aeroforce tech they plug into the obd port under your dash , they can display a lot of information


http://aeroforcetech.com/products_order_gm.html

If you are looking to buy a truck around that era I'd suggest focusing on the 2006 - 2007 LBZ engine trucks.

LLY is a good engine, but the LBZ is probably the best one they ever made. And the last pre-emission Duramax as well.

I have the LML engine now and it uses more fuel and I believe makes less power (or its a close push) than my 2006 LBZ did.

Go to dieselplace.com , click on forums then go to 2005-2006 lly. There you can find anything you want to know about the motor.

The oil pressure is always low on the lly. Had one for 9 years before getting a new GMC. One thing you should check is for a head gasket issue. The lly could develop a problem that is a very expensive fix. I had the head gasket issue and repaired it, other than that the truck was flawless.

At 310 hp you need a programmer to help with pulling a heavy load. I always kept mine in the towing mode which added about 50 extra horse.