REAL MAN TRUCKWORKS & SURVIVAL

VEHICLES, CAMPERS, and BOATS => General Vehicle Related Discussion => Topic started by: dave945 on April 08, 2021, 09:09:06 PM

Title: 2004 Chevrolet Express 2500
Post by: dave945 on April 08, 2021, 09:09:06 PM: Wanted to pick your brains. My van has a 6.0 in it, about 495000 miles. It’s had low oil pressure for quite a while, but would usually sit around 40’when driving. The other day it dropped out completely. Now when starting from cold, pressure goes up to 25 and sits there for about 90 seconds as then over the next 30 seconds will slowly drop down to zero. If I rev the engine, pressure comes back up to 25 but then drops right back to zero. I’m thinking/hoping that I’ve got the oil pickup o ring issue common on these engines. I don’t think it’s the oil pump, but I may be deluding myself.

Any thoughts? I’m ready to get the o ring and pan gasket and try it.

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Title: Re: 2004 Chevrolet Express 2500
Post by: Flyin6 on April 08, 2021, 09:52:00 PM: Not sure if you have the same issue, but my son's V-Max 6.0 with the 4 cyl mode has a little filter in an oil passage that feeds the dual mode shutting off 4 cylinders by collapsing the lifter. To repair, you pull the intake, replace or clean the filter and drive on for another 300K

But if your engine is a LQ4, then forget everything I just said...and I'm thinking you have the LQ4
Title: Re: 2004 Chevrolet Express 2500
Post by: stlaser on April 08, 2021, 09:58:35 PM: Cam bearings are crimped oem, when they go you lose oil pressure and it wipes crank out.

You can have a machine shop swap them for solid bearings. At 500k it needs overhauled most likely, when we source 6.0ls motors for swaps we have the cam bearings addressed while motor is out.
Title: Re: 2004 Chevrolet Express 2500
Post by: KensAuto on April 08, 2021, 10:07:58 PM: Definitely sounds like the o-ring.
Not sure how you still have cam bearings at that mileage tho. Lol

Those oil pumps rarely fail, but when they do it's usually the relief valve...once it sticks open, it won't be speratic. All or nothing basically

Edit: sometimes the sender acts exactly like a bad o-ring, so keep that in mind. That's why we always check with a mechanical gauge first.
Title: 2004 Chevrolet Express 2500
Post by: dave945 on April 09, 2021, 11:35:40 AM: Quote from: Flyin6 on April 08, 2021, 09:52:00 PM
Not sure if you have the same issue, but my son's V-Max 6.0 with the 4 cyl mode has a little filter in an oil passage that feeds the dual mode shutting off 4 cylinders by collapsing the lifter. To repair, you pull the intake, replace or clean the filter and drive on for another 300K

But if your engine is a LQ4, then forget everything I just said...and I'm thinking you have the LQ4
It’s the LQ4, don’t remember why I’m telling you that, I forget what you were saying.....

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Title: Re: 2004 Chevrolet Express 2500
Post by: EL TATE on April 14, 2021, 06:35:47 PM: if you guys recall a couple years back my 04 Yukon 6.0 did the same thing. cracked o ring at the pickup tube contributing to worn cam/crank thrust bearings creating hovering oil pressure then plummeting oil pressure. the news is not looking good for you my friend. I got a complete reman with a 3 yr warranty from LKQ. yours doesn't have the 4 cyl mode and the pickup sensors are not problematic on the older LQ4. you're probably rebuilding.
Title: Re: 2004 Chevrolet Express 2500
Post by: dave945 on April 14, 2021, 08:07:55 PM: We’ll see what happens after i swap the o ring on the pickup tube. I hope I’m not rebuilding, it would be a new van(which is in the plans anyway but not immediately). Then I can rebuild the engine and stick it in the blazer.

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Title: Re: 2004 Chevrolet Express 2500
Post by: JR on April 16, 2021, 05:29:23 PM: At 500k that would be like missing a shotgun blast. Dang good life there for a gasser, like my 87 elky 305.
Title: Re: 2004 Chevrolet Express 2500
Post by: dave945 on April 17, 2021, 08:31:33 AM: So I would like to start out by saying that Heavenly Father must really love me right now. Got the o ring swapped and everything put back together last night, finishing around 3 AM. Didn’t test run or drive it until this morning because I couldn’t find my keys.

So to make a short story long, here’s a couple before pictures:
Startup
(https://uploads.tapatalk-cdn.com/20210417/f5dc0497436f809928259f1c8fe2b37a.jpg)
2 minutes later
(https://uploads.tapatalk-cdn.com/20210417/154e24649a43534534ee90a0d9d7d52a.jpg)

Parts
(https://uploads.tapatalk-cdn.com/20210417/ddc91c4c88e6cb3dc51755e1fb316909.jpg)
Dirty parts
(https://uploads.tapatalk-cdn.com/20210417/8989ab19b45b34e97f104aa292e636f8.jpg)
O rings, both old and new
(https://uploads.tapatalk-cdn.com/20210417/fd5a0ec4740e051f404e7157bd57568b.jpg)
Oil pressure on first startup
(https://uploads.tapatalk-cdn.com/20210417/723e0db122ce8ebbdcd32a7f682122b8.jpg)

It maintained about 38 psi after the first drive and getting warmed up. The oil pan gasket and the o ring were original equipment, I had to drill the rivets on the oil pan to get the old gasket off. The o ring was flat and not pliable at all. So far I think I dodged the proverbial bullet and was blessed by a Heavenly Father who could tell I wasn’t ready to buy a new van yet.

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Title: Re: 2004 Chevrolet Express 2500
Post by: stlaser on April 17, 2021, 08:41:40 AM: Wow, definitely lucked out there :likebutton:
Title: Re: 2004 Chevrolet Express 2500
Post by: JR on April 17, 2021, 01:08:50 PM: Nice when it goes your way.
Title: Re: 2004 Chevrolet Express 2500
Post by: Flyin6 on April 18, 2021, 11:13:27 AM: Praise the LORD!
Title: Re: 2004 Chevrolet Express 2500
Post by: EL TATE on April 19, 2021, 10:04:02 AM: Quote from: Flyin6 on April 18, 2021, 11:13:27 AM
Praise the LORD!

no kidding! good for you.
Title: Re: 2004 Chevrolet Express 2500
Post by: cj7ox on April 19, 2021, 03:26:11 PM: Outstanding!
Title: Re: 2004 Chevrolet Express 2500
Post by: Bigdave_185 on April 19, 2021, 08:16:36 PM: Amen

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