Valve Stem Seals

[Nate’s Dmax]

I’ve been thinking about valve stem seals here lately. It seems the aftermarket stem seals want to ride up or not seal properly. The OEM ones seem to do better. Now here is what I’ve been thinking and wondering. Would the L5P stem seals work on the previous gen Duramax? The L5P seals have the plate that the spring sits on incorporated into the seal so thus no chance of ridding up on the stem. Could i use the L5P seals on like my LBZ to prevent the seal from loosening and ridding up on the stem?

 

[Chevy1925]

Uh, the only time i see older ones fail is from being smashed on. What instances are you seeing these coming up off the valve stem?

 

[Nate’s Dmax]

Uh, the only time i see older ones fail is from being smashed on. What instances are you seeing these coming up off the valve stem?

The OEM ones seem to work good. It’s the aftermarket ones like Mahle and Felpro that dont say seated. I’m just thinking if the L5P ones would fit that would eliminate the seating problem.

 

[Chevy1925]

I have had aftermarket on both sets of my heads and on many of the other trucks weve done. We only use mahle but no issues

 

[TheBac]

Moved to Engine Building.

(I have to admit I thought "wheels" at first.)

 

[darkness]

(I have to admit I thought "wheels" at first.)

Same ?

 

[Bdsankey]

I have personally not seen this condition with Mahle either. All we use at my shop are Mahle or genuine GM and they've all stayed seated including on my engine we ran up to 5200-5500rpm area for multiple sled pulling seasons.

 

[1FastBrick]

I guess the question I have, is how are the ones that you see failing being installed?

I believe James is 100% about them being smashed on.

Based on what I read, they don't like being pushed all the way down. Even GM say's they will fail if there bottomed out. Of course GM has a tool that seats them to the recomended depth.

Kent Moore J-44640 for the 6.6L
Kent Moore EN-50723 for the 2.8L
Kent Moore EN-50346 for the 3.0L

 

[Nate’s Dmax]

The ones I’ve seen fail are being installed by the machine shop doing the rest of head work. So maybe its the machine shops method of installing them as they would have been all done by the same shop. I do have the tool in my GM 6.6 service kit and will use it to fix my own truck And others.

 

[Chevy1925]

The ones I’ve seen fail are being installed by the machine shop doing the rest of head work. So maybe its the machine shops method of installing them as they would have been all done by the same shop. I do have the tool in my GM 6.6 service kit and will use it to fix my own truck And others.

That would explain it. I know of a couple machine shops out here that would do the same thing.

 

[1FastBrick]

Most machine shops have a universal kit like this one below and they just push them down till they seal. often that also bottoms them out. On 1 of these forums, Some one posted a document from GM I believe were they specified that if the seal was not installed correctly and was bottomed out it would cause an issue with oil consumption.

 

[Nate’s Dmax]

Most machine shops have a universal kit like this one below and they just push them down till they seal. often that also bottoms them out. On 1 of these forums, Some one posted a document from GM I believe were they specified that if the seal was not installed correctly and was bottomed out it would cause an issue with oil consumption.

View attachment 129854

Would using a tool like that cause them to actually come off of seat and ride up on stem?

 

[1FastBrick]

Would using a tool like that cause them to actually come off of seat and ride up on stem?

It should not, unless they pound them on and they are bottomed out.