No oil pressure at start up, 2001 Tahoe

[JonnyTahoe]

Well my old pressure finally goes to 0 now it idle. Normally at idle it would be about 20 and the highest it high RPM at 40. I have 283 k on it right now I have four wheel drive how hard is it to drop the front axle a little forward?

Your idle pressure should be around 30-40. When your pressure drops to 0 do you hear your lifters ticking? mine would and not just a little bit a lot. My cold start was totally normal oil pressure but it would slowly drop down to 0 within about 5-10 min. If you have no lifter noise what so ever and your pressure is not doing what mine was doing it could be another issue. Your miles are right where mine were when I started having pressure issues so if your O-ring is the original (green) and it most likely is it is good to replace it sooner rather than later. Watch a few YouTube vids and you will get a good idea of what is all involved.

 

[clandr1]

Well my old pressure finally goes to 0 now it idle. Normally at idle it would be about 20 and the highest it high RPM at 40. I have 283 k on it right now I have four wheel drive how hard is it to drop the front axle a little forward?

If you hear ticking, my first move would be to change the oil pickup tube o-ring.
If you do not hear ticking, it's likely a bad sensor or stepper motor.

 

[Merc1973]

If you hear ticking, my first move would be to change the oil pickup tube o-ring.
If you do not hear ticking, it's likely a bad sensor or stepper motor.

Actually no ticking of the lifters surprisingly. When i replaced my intake gasket and knock sensors I did not replace the oil presssure sender since I needed a special socket/wrench to get it out. It is still able to be removed with intake installed?

Your idle pressure should be around 30-40. When your pressure drops to 0 do you hear your lifters ticking? mine would and not just a little bit a lot. My cold start was totally normal oil pressure but it would slowly drop down to 0 within about 5-10 min. If you have no lifter noise what so ever and your pressure is not doing what mine was doing it could be another issue. Your miles are right where mine were when I started having pressure issues so if your O-ring is the original (green) and it most likely is it is good to replace it sooner rather than later. Watch a few YouTube vids and you will get a good idea of what is all involved.

Hmmm... It started up normal with pressure at 20 like it always has, never made any lifter clatter since I owned it, and I know that that sounds like. 10 min drive and stopped at a stop light and the dash started beeping at me with low pressure, revving RPMS to 3000k up does give 20 PSI, normally that would register at 40 PSI. I driver it back home in tow mode to keep the RPMs up. I never had good oil pressure. I bought a pan gasket and O-ring https://www.amazon.com/gp/product/B0049839P2 It is black I think though. Looking in the past service records of the truck from the PO, the pump was done about 150k. Sucks as I just changed the oil and filter 300 miles ago. I have a really really bad oil leak anyways, hopefully its the pan gasket. I loose about 2-3 qts every 3k miles, it's DIY under-body rust-proofing!!!

 

[clandr1]

Actually no ticking of the lifters surprisingly. When i replaced my intake gasket and knock sensors I did not replace the oil presssure sender since I needed a special socket/wrench to get it out. It is still able to be removed with intake installed?

I believe so, but not sure. For the majority of projects I'm contemplating, I find that watching as many YouTube videos as possible really helps give me a good idea of what I'll encounter, and how to get the job done with the least amount of trouble. I would suggest some serious video watching and internet research to see what it takes to replace the oil pressure sensor.

 

[JonnyTahoe]

Actually no ticking of the lifters surprisingly. When i replaced my intake gasket and knock sensors I did not replace the oil presssure sender since I needed a special socket/wrench to get it out. It is still able to be removed with intake installed?




Hmmm... It started up normal with pressure at 20 like it always has, never made any lifter clatter since I owned it, and I know that that sounds like. 10 min drive and stopped at a stop light and the dash started beeping at me with low pressure, revving RPMS to 3000k up does give 20 PSI, normally that would register at 40 PSI. I driver it back home in tow mode to keep the RPMs up. I never had good oil pressure. I bought a pan gasket and O-ring https://www.amazon.com/gp/product/B0049839P2 It is black I think though. Looking in the past service records of the truck from the PO, the pump was done about 150k. Sucks as I just changed the oil and filter 300 miles ago. I have a really really bad oil leak anyways, hopefully its the pan gasket. I loose about 2-3 qts every 3k miles, it's DIY under-body rust-proofing!!!

I have leaks too. Don't worry about only 300 mi on your oil. I drained out 300 mi on a Royal Purple oil change was making my Rear Seal leak.

 

[Merc1973]

I'm doing this tomorrow and will update afterwards. I received my Felpro o-ring from Amazon. It was black but the correct part number with manufacture date 10/19/20. Other pics on amazon reviews show a red o-ring and their bags are dated 2019 and earlier. I called Felpro and the guy said I was not the first to ask about this and he was waiting for an engineer to answer him... I need the truck ASAP, so I might see it it fits.

 

[JonnyTahoe]

Replaces GM; 12584922. These are available at most auto stores.

 

[Merc1973]

Thanks. I installed it yesterday. 4.5 hour job, even with air tools, with wasted time cleaning the oil pan and aligning oil pain and gasket together.. it world take much longer with only hands tools. 2 zipties helped to keep the gasket aligned and a dollop of RTV on block at cornes for frontand rear covergaps .. Dropping the axle down is simple enough, 21mm ratcheting wrenches make it easy for driver's side mounts. At 285k I had very little sludge and the color of the engine internals were honey/ golden brown, which in my opinion is pretty good. Many of the YouTube videos I watched had dark brown almost black pan and engine internals. It's had synthetic oil is whole life and it shows.

I measured the specs given to me by Felpro and the black was same using my digital calipers. My date code is newer than yours.

My pressure was at 40 at cold start. Dropped to 30 and was bouncing around erratically , I will install the new pressure sensor next week. Maybe that's the problem??? No oil drips or leaks underneath after letting it idle for 30 min so my terrible leak is fixed. I'm not 100% satisfied, I'll find out next week. Even in the cold start and not priming oil pressure by pulling fuel pump relay there was no clatter of the lifters. In trying the Costco Kirkland 5w/30 full surgeon for first time and usual Napa gold/with filter.

 

[JonnyTahoe]

As you can see not all the oil drains out of the oil pan and it's nice to clean all that out while you have it off. I went as far as going to my local car wash with car ramps and washed off all the oil and grime under the entire engine, the front of the oil pan and the crossmember which helped keep me and my floor a bit cleaner. I also removed and cleaned the tray that is below the bottom of the engine.

 

[Merc1973]

I didn't mean it was an actual waste of time. I'll say time consuming instead. 4 cans or brake cleaner...