06 5.3 low oil pressure on start up

Kenz9306 · February 26, 2015

Truck has 236xxx miles, recently in cold weather I've been getting low oil pressure for the first 3-5 seconds on startup after sitting overnight. Doesn't do it when it's warmer out (above 50) and pressure typically is about 35-40 when driving. I've read a lot of forums but mechanic said it's losing its prime.. Basically saying I need a rebuild... Any advice would be much appreciated.

99 2500 · February 26, 2015

More than likely it is the o-ring where the pickup tube goes into the pump. At this mileage I would just put a new oil pump and o-ring an it will probably be good as new.

Kenz9306 · February 26, 2015

More than likely it is the o-ring where the pickup tube goes into the pump. At this mileage I would just put a new oil pump and o-ring an it will probably be good as new.

That's what I was thinking but everyone wants an outrageous amount to fix.. Was quoted 1200 from the dealership.. And about 1100 from my local mechanic.. Is this something I could do myself?

99 2500 · February 26, 2015

If it's a 2 wheel drive it's pretty easy to do, 4 wheel drive is way more difficult

Kenz9306 · February 27, 2015

If it's a 2 wheel drive it's pretty easy to do, 4 wheel drive is way more difficult

It's 4x4..

DwayneJ · February 27, 2015

Oil filters usually have a drainback valve. Have you had this problem with multiple filter changes?

Far as DIY on the oilpump we have no idea what your skill, equipment and facilities are.

Kenz9306 · February 27, 2015

No clue on the oil filter. Haven't driven it far enough to warrant oil change yet. But today I was going to drive it over to mechanics and now I can't get any oil pressure at all. It's just sitting at 0. Vague ticking stared after a minute. Shut truck off as soon as noise came from engine. It's has never stayed at 0. Typically just very slowly went up. Pretty convinced it's my oil pump.

00Silverado4x4 · February 27, 2015

Did you confirm the oil level is good?

99 2500 · February 27, 2015

That's your oil pump, pressure relief valve is stuck open

Daryl Z71 · February 27, 2015

I currently have this same issue with my 06 at 233k miles. I'm in the process of preparing another motor though to do a swap, but I installed a new oil pump in it yesterday. It's not something I'd want to do with the motor in the truck, but I think it could still be done...

99 2500 · February 27, 2015

Yes can be done in vehicle pretty easy especially if 2wd, have done about 4 different gm vehicles.

Kenz9306 · February 27, 2015

I think I'm going to take it to my friends shop, he doesn't normally do things like this (specializes in 4x4 builds) but he's done it before and offered for me to use his lift and such but I get to do all the work and he'll walk me through it. (boyfriend is still convinced 100% my motors toast, doesn't believe it could be the oil pump.)