No oil pressure at start up, 2001 Tahoe

[2006Tahoe2WD]

What other "while-you-are-in-there" items should also be done?

 

[Rocket Man]

$1100-1500 to do the o-ring…!?? What are we talking about having done?

I’m assuming the oil pump since the shop won’t do the o-ring without doing that too.

 

[Sam Harris]

I don’t really know, but damn that sounds high to me.

 

[Bofiggy]

Local shops are willing to change out the oring however they also require dropping the front drive..yeah yeah.. the kicker is they all will only warrantee job if they change oil pump,WP,etc.. or they wont do it. As well, everyone is booked up for 3+ weeks.

So its down to wrenching for me... Last year this time I changed my timing belt on a lexus- LS400. that was fun. this job seems much easier other than dropping the diffand being under it. all good

 

[OR VietVet]

Local shops are willing to change out the oring however they also require dropping the front drive..yeah yeah.. the kicker is they all will only warrantee job if they change oil pump,WP,etc.. or they wont do it. As well, everyone is booked up for 3+ weeks.

So its down to wrenching for me... Last year this time I changed my timing belt on a lexus- LS400. that was fun. this job seems much easier other than dropping the diffand being under it. all good

It's all in the prep beforehand. Nice flat area to work on, proper support by correct size jack stands, great assortment of tools on hand, watch multiple you tube videos for the same job. One thing my girl did for me is she got me 3 4x8 3/8" roll out pads, like a yoga mat, that I put on the ground and lay on. Have plenty of drain pans and an appropriate assortment of capped carriers to put the fluids in for easy disposal. Make sure you have all needed components for replacement and be methodical about each step. Have plenty of shop towels. Have a friend there if can that is a second hand and can also hand you tools as needed. Don't let a roadblock piss you off. It will happen and just take a deep breath and move on. Just remember the money you are saving and plan on doing something with that saved money.

Remember, "cleanliness is next to Godliness". Clean as you go and be sure all surfaces are clean as you reassemble.

 

[2006Tahoe2WD]

Yes, all that. Many of us have been there many times.

 

[Douglas Friedberg]

Great info you make me feel good at 250,000 and rolling. By the way a great check for that oil pump seal is overfill the crankcase oil by 1-2 qts won’t hurt a thing and if that problem goes away you know what you have to do and you’ll be nicer to motor that way

 

[OR VietVet]

Great info you make me feel good at 250,000 and rolling. By the way a great check for that oil pump seal is overfill the crankcase oil by 1-2 qts won’t hurt a thing and if that problem goes away you know what you have to do and you’ll be nicer to motor that way

The overfill of the oil should not be left that way. The method of overfill and point downhill and see if problem stops, is a method for diagnosis but the overfill should not be left that way.

 

[nonickatall]

Local shops are willing to change out the oring however they also require dropping the front drive..yeah yeah.. the kicker is they all will only warrantee job if they change oil pump,WP,etc.. or they wont do it. As well, everyone is booked up for 3+ weeks.

So its down to wrenching for me... Last year this time I changed my timing belt on a lexus- LS400. that was fun. this job seems much easier other than dropping the diffand being under it. all good

Changing the o-ring is no problem at all. You have to loosen and remove the carrier that is screwed across the bottom of the axle with four screws. Then you have to loosen the differential, which is screwed in three places, and move it down a little. Then you unscrew two oil lines that go to the oil cooler and then the oil pan. Then the oil pipe, change the O-ring and everything back.

I did this on the lift and it took maybe 1.5 hours.

It's definitely not very comfortable lying under the car, but it works as well.

 

[Eldiablo]

Wow that is awesome!

 

[2006Tahoe2WD]

My 04 Z71 has 245k. These trucks last if you take care of them. I have had zero oil pressure issues since I put the O ring in. hope this thread eventually helps someone avoid a very expensive "rebuilt" just because a $3 oring goes bad.

Again, good write up. I'm watching my oil pressure and it is now 32psi at cold start and rev it up without change. So I think I have the O-ring issue.

 

[2006Tahoe2WD]

Again, good write up. I'm watching my oil pressure and it is now 32psi at cold start and rev it up without change. So I think I have the O-ring issue.

I think the issue is verified. The mechanic overfilled the oil about 2/3 quart? The pressure went up from 26 to 32 cold start. I read somewhere about testing the O-ring by overfilling and cold starting with the rear end up in the air. Yesterday (with the overfilled oil) I coldish started on a steep downhill driveway and the pressure went right to 40-45. I think this confirms that I have a pick-up tube O-ring that is not good.

 

[nonickatall]

So swap it, it's not a big deal. I did it myself. When you do it swap as well the pressure relief valve which also can make trouble and is accessible when the oil pan is down.

 

[nonickatall]

Here a small description...

No oil pressure at start up, 2001 Tahoe

What other "while-you-are-in-there" items should also be done?

www.tahoeyukonforum.com

 

[2006Tahoe2WD]

Here a small description...

No oil pressure at start up, 2001 Tahoe

What other "while-you-are-in-there" items should also be done?

www.tahoeyukonforum.com

Yes, I think I'm going to have it changed out. I probably will not do it myself - years ago I would DIY when I had a spare car. Thanks for the while-you-are-in-there info.

 

[2006Tahoe2WD]

On another thread I explained the result after getting the O-ring changed. Oil pressure fixed. I guess I should have posted here but I got mixed up. Look in the 2007+ section of the forum.

 

[Eldiablo]

For the past 45k miles my truck has had its oil pressure drop to zero, within 20-30 seconds after start up. It was not the result of a bad sensor as I tried replacing that first, besides, the loud ticking that would almost always follow was a pretty good sign of the problem. If I immediately took off driving, the pressure would stay up, but I had to keep the rpm's up. Once the vehicle warmed up everything functioned normally until the engine got cool again.

I bought an oil pump with the intention of changing it out but a friend told me to just change out the oil sump O-ring instead as usually that is the issue with no oil pressure in a 5.3.

On a 2x4 Tahoe it is very straight forward to drop the oil pan to access the sump and access the O ring. You have to remove the cross brace under the oil pan which is 4 bolts. You also need to remove the two oil pan/bell housing cover bolts (they hold a small plastic shield in place that keeps road grime out the bell housing. You also need to remove two bolts that hold the wiring harness in place. A simple electrical connector on the low oil sensor then you can drop the pan by removing all of the pan bolts.

Once the pan is down there are two nuts that hold the oil sump to the main bearing caps, as well as the small bolt that actually bolts the sump tube to the bottom of the oil pump. I removed the O ring and it was flattened out like a wedding ring, but not cracked or deteriorated. It was very loose when pulling out the tube as well. I put the new O ring on, which was $2 and shaped more like a fat doughnut. It was harder to press the oil sump tube back into place but it was fairly easy.

Scotch bright pad was used to clean the grime from the block where the oil pan gasket seats. I had a bad oil leak forever and the pan gasket was the culprit as it had long since flattened out as well. Once the oil pan was cleaned up and both surfaces cleaned for a new gasket I had the truck back together and running in less than 3 hours.

High oil pressure once again. With 526k miles this is the most extensive "tearing" into the drive train I have had to do, other than a 2-3 shift solenoid going back in the transmission a while back.

Hopefully this thread will help anyone with similar oil pressure issues who thinks they need a new engine, when in reality you can fix it for $60 in parts and an oil change.

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Put a little bit of marvel mystery oil in it at next oil change works wonders on the lifters and such. You will be shocked.

 

[Eldiablo]

It would have been nice to roll in a new set of mains and rod bearings while you were in there. 526 amazing. Its a race to a milliion miles.

 

[grizzlyak]

This is awesome. I've been noticing my oil pressure gauge needle fluttering, but never going to zero. I keep expecting it to, and as it always seems to get much more stable with an oil change, I've just assumed it was the sending unit, which, I understand, is very hard to get to, down low, on the back top of the engine. WHY??? At any rate, maybe THIS is the problem, and may be something I can do myself. I've never considered removing that cross-member (I was also afraid I couldn't get it back on and the truck would go down the road sideways!) Question though, did you notice your needle fluttering before it dropped completely? Or was it fine until it wasn't?

 

[clandr1]

This is awesome. I've been noticing my oil pressure gauge needle fluttering, but never going to zero. I keep expecting it to, and as it always seems to get much more stable with an oil change, I've just assumed it was the sending unit, which, I understand, is very hard to get to, down low, on the back top of the engine. WHY??? At any rate, maybe THIS is the problem, and may be something I can do myself. I've never considered removing that cross-member (I was also afraid I couldn't get it back on and the truck would go down the road sideways!) Question though, did you notice your needle fluttering before it dropped completely? Or was it fine until it wasn't?

Usually when the oil pressure sensor fails, it goes all the way to zero, or pegs at max PSI. IMO, fluttering of the oil pressure gauge is either some sort of debris that is impeding the flow of oil from time to time, or it's your oil pressure gauge stepper motor that is on it's way out. Someone who knows more will probably be along shortly to chime in.