The truck is still running great and I daily drive it to work everyday. No issues beside my tune not being complete (since I pieced it together) and #2 seems to be burning a little oil. Not enough to foul the plug, but enough to leave a burned white crust on it. It also gives a puff of smoke on start up. Especially after running it hard, it seems. Hard to tell since I run it hard pretty often.

At first I just figured it was because I reused those 165k mile piston rings (which would be expected) but then I found that the oil was on top of the intake vavle. So that drew me away form thinking its the rings. I had pulled the intake for something else and found that the #2 cylinder intake valve was closed and there was a puddle of oil on top of that valve. #2 is the only one burning oil.

The only ways that I can think of for oil to get on top of the intake valve is that:

- Leaking oil out of the rocker bolt hole that I cut open when porting.
For those of you that don't know, it is normal to cut into the threads of the rocker port when porting your heads. I thought it was sucking oil down the threads at first since I hadn't use thread sealer, but I've since RTV'd the bolt threads and still have oil burn. So I don't see how it could still leak.

- Oil blow by from the PCV system and sucked into intake
I doubt it's the PCV because that is at the opposite side of the engine than the PCV vacuum port. But I do have the normal excessive oil coating the inside of the ports from the PCV. So I swapped out to the LS6 valley cover and PCV pick-up to reduce that. I plan to install a catch can also.

- Bad valve stem seal (praying for it to be this one)
I plan to change out the valve stem seal soon.

- Bad valve guide
Valve guide will be a last resort.


I'll update after I change out the valve stem seal or once I find the source.

Merry Christmas Everyone!

 

I would bet on the valve seal my self...

Try using Valvoline Max Life for high milage engines and see if it reduces or goes away. My 2000 did this at 80k and was burning 2 quarts of oil over 2000 miles. I tried this as a last resort and It now has 165k+. It only smokes on start up if I run the **** out of it hard.

 

I've heard that a lot. It seems that a thicker oil will help these motors quit burning oil. That was another thing on my list, but I wanted to wait to see if the seal stopped it first. I think the thicker oil would be more focused on the rings and I'm trying to pinpoint it.

Thanks for sharing your experience FastBrick! Thats another tic showing that a different oil approach had helped stop burning it.

 

They do offer a 5w30. It's not so much thicker oil as it is the additives they use in the high milage oil. It seems to swell up the seals. I know its a few more dollars for an oil change but I have seen it make a difference on several vehicles.

 

ah, ok. Good info. Thanks! I've never believed there was a difference in that oil before. Thought it was just placebo. lol Good to know!

 

I know it sounds like that... Especially with me pushing people to atleast try it.

I'm almost positive the rings are stuck on my 2000. But it still runs strong and it doesn't use oil when running the Valvoline High Mileage.


I have run engine flush's, marvel mystery oil, and even tranny fluid through the motor. It will free up a sticking lifter but it still seems to have excessive blow by judging by the oil changes compared to other LS vehicles I have owned and worked on.

I have always wanted to take it apart and inspect it, but I Have enough projects and not enough time or space...

 

Here's a picture of that coincidental moment when I found the intake vavle closed on #2 and a puddle of oil on top of the valve. I was surprised to see this.

 

Damn! There is your smoking gun...

 

Yea, I just pray its not a guide and only the seal.

 

Although I don't work at an engine shop so I don't have first hand knowledge. I believe the Valve guides are Powdered metal. There usually pretty durable so unless it's bent a valve in the past or had alot of runs with no oil I doubt the guide is bad.

It seems more common for the valve seal to get damaged during installation.

It might not hurt to have a machine shop look over the stems and guides.

The guides may need a hone and the stems may need a polish. But I'm still certain the seals are the root cause of the issue. Did you thoroughly lube the valves when you installed them? Something more than runny assembly lube?

I believe its a common practice to use white grease or something grease like with a high pressure rating to protect them on startup as Oil will get wiped away real fast.