07 denali oil pan gasket,pickup o-ring

[j91z28d1]

is it still soft and rubbery? or hard like it's going to crack when you bend it?


did you see a hot idle increase in pressure?

 

[2006Tahoe2WD]

is it still soft and rubbery? or hard like it's going to crack when you bend it?


did you see a hot idle increase in pressure?

The old O-ring bends fairly easily but I haven't bent it vary far. I don't want to break it now. When pushing in on it, it seems hard. The hot idle is higher but not by much, maybe 5 psi.

 

[j91z28d1]

The old O-ring bends fairly easily but I haven't bent it vary far. I don't want to break it now. When pushing in on it, it seems hard. The hot idle is higher but not by much, maybe 5 psi.

thanks. I'm always curious about these o rings.

 

[2006Tahoe2WD]

thanks. I'm always curious about these o rings.

The pickup tube O-ring is definitely an issue. There are countless YouTube videos and forum posts that mention this. I bet I've seen/read at least half of them. One of the symptoms is low cold idle pressure that improves (gets higher) as the engine heats up. This is exactly what I had. I also overfilled the oil a bit and went down a steep hill and started braking and the pressure went up. This is a test mentioned to confirm the O-ring issue. You can also lift the rear up 2-3 feet and get the same effect.

 

[j91z28d1]

The pickup tube O-ring is definitely an issue. There are countless YouTube videos and forum posts that mention this. I bet I've seen/read at least half of them. One of the symptoms is low cold idle pressure that improves (gets higher) as the engine heats up. This is exactly what I had. I also overfilled the oil a bit and went down a steep hill and started braking and the pressure went up. This is a test mentioned to confirm the O-ring issue. You can also lift the rear up 2-3 feet and get the same effect.

oh yeah. I believe it. it's just very weird to me how random it is. how one truck can go 100k and another go 250k on the same part. wish I knew the maintenance history. maybe some oil type or spec eats whatever the rubber is?

it's cool you did the add oil and done hill test. I do feel that's the proper way but so few actually do it. they seem more happy to pull half the front of the truck apart to change an o ring and then wonder why it's still got low pressure.

I'm at 165k and just wondering when or if it's going to happen to mine. the only experience I have with one is my ls3 car. over 100k, seen well over 300deg oil Temps, which I bet these trucks have never seen.. hard track day use, me being dumb and over heating it well into the 260 range. ecm went into full lock down mode. I thought forsure I'd be doing head gaskets. but while in there checking bearings which looked perfect amazingly, I replaced the o ring with one from the gm dealer that showed for my car. it was blue like the one that came out. the one that came out wasn't perfectly round but was very flexible and showed no signs of failing or getting brittle to me. looked perfect to me. had these not been a common problem, I wouldn't even have replaced it.

I've changed probably a 100 different kind of o rings on all kinds of different industral equipment over the years, I've never seen one, even leaking ones come out looking as bad as some of these pickup tube ones I've seen online where they just crumble into pieces and these are also just the cheap back rubber ones used on all kinda crazy oils and temp ranges.


gm did this funny thing, where the ls is awesome for using all rubber good designed gaskets and o rings, and then they found a why to spec rubber that isn't oil resistant. everything starts leaking anyway as if they still used cork. it kinda blows me away.

 

[2006Tahoe2WD]

oh yeah. I believe it. it's just very weird to me how random it is. how one truck can go 100k and another go 250k on the same part. wish I knew the maintenance history. maybe some oil type or spec eats whatever the rubber is?

it's cool you did the add oil and done hill test. I do feel that's the proper way but so few actually do it. they seem more happy to pull half the front of the truck apart to change an o ring and then wonder why it's still got low pressure.

I'm at 165k and just wondering when or if it's going to happen to mine. the only experience I have with one is my ls3 car. over 100k, seen well over 300deg oil Temps, which I bet these trucks have never seen.. hard track day use, me being dumb and over heating it well into the 260 range. ecm went into full lock down mode. I thought forsure I'd be doing head gaskets. but while in there checking bearings which looked perfect amazingly, I replaced the o ring with one from the gm dealer that showed for my car. it was blue like the one that came out. the one that came out wasn't perfectly round but was very flexible and showed no signs of failing or getting brittle to me. looked perfect to me. had these not been a common problem, I wouldn't even have replaced it.

I've changed probably a 100 different kind of o rings on all kinds of different industral equipment over the years, I've never seen one, even leaking ones come out looking as bad as some of these pickup tube ones I've seen online where they just crumble into pieces and these are also just the cheap back rubber ones used on all kinda crazy oils and temp ranges.


gm did this funny thing, where the ls is awesome for using all rubber good designed gaskets and o rings, and then they found a why to spec rubber that isn't oil resistant. everything starts leaking anyway as if they still used cork. it kinda blows me away.

Yes, It could be the order in which the oil tube bolts are installed. If you do the bolt near the O-ring first you might be less likely to "pinch" or "skew" it. This could be why some go 250k miles and others 100k miles. My O-ring looks like it was skewed.

Without some analysis we don't know what the O-ring is made from. Could be Viton but probably not - I don't know what is the best in this case. What ever it is it ended up taking the shape of the void left for it without continuing to push back enough.

 

[j91z28d1]

huh I do wonder if they are installed on random sides. that would be interesting.

I will say I've never in my life seen something with a flange like that and only have one bolt from the factory. that was an interesting decision as well.

 

[2006Tahoe2WD]

huh I do wonder if they are installed on random sides. that would be interesting.

I will say I've never in my life seen something with a flange like that and only have one bolt from the factory. that was an interesting decision as well.

Maybe not the best but the tube is supported at two other points.

 

[rdezs]

Saved yourself an ungodly amount of cash by doing it yourself

It's a little late to ask, but did you get the pickup tube girdle that you utilizes both bolt holes on the oil pump? Less than $20, I figure it's worth the additional insurance.

 

[donjetman]

here's my 2nd bolt install (no collar):https://www.tahoeyukonforum.com/threads/valley-cover-crank-pulley-etc.149036