2007 Tahoe/New member from sunny California/Looking for some advice

[Caligirl]

I have been advised by a few in these forums to check to see if the valve cover on the driver's side over the PCV system has been updated to the "new" version (outlined in the service bulletin #10-06-01-008F) and from what I understand, it is recommended even with AFM disabled/deleted (?)

Question is, can you tell by looking at the valve cover without having to uninstall it to see if it is the new one? I see from the pics in the bulletin and the video I watched that the new one has a square opening vs an oval opening, but can you see that on the outside of an installed cover?

Thanks!

 

[iamdub]

I have been advised by a few in these forums to check to see if the valve cover on the driver's side over the PCV system has been updated to the "new" version (outlined in the service bulletin #10-06-01-008F) and from what I understand, it is recommended even with AFM disabled/deleted (?)

Question is, can you tell by looking at the valve cover without having to uninstall it to see if it is the new one? I see from the pics in the bulletin and the video I watched that the new one has a square opening vs an oval opening, but can you see that on the outside of an installed cover?

Thanks!

The valve cover has nothing to do with AFM. LS engines have oily PCV systems- period. AFM just exacerbates it so then the updated cover is even more beneficial.

Unfortunately, you can not tell from outside if you have the updated cover. I found mine already had it when I went to install one I had bought.

After you get (or confirm that you already have) the cover, top it off with a catch can. A ~$20 one on Amazon is all you need. We can cover the details when you get to that point.

 

[Caligirl]

The valve cover has nothing to do with AFM. LS engines have oily PCV systems- period. AFM just exacerbates it so then the updated cover is even more beneficial.

Unfortunately, you can not tell from outside if you have the updated cover. I found mine already had it when I went to install one I had bought.

After you get (or confirm that you already have) the cover, top it off with a catch can. A ~$20 one on Amazon is all you need. We can cover the details when you get to that point.

So if I delete the AFM via the ECM, is the updated valve cover something I should even deal with right now? Thus far, no oil consumption since we purchased almost a month ago.

 

[donjetman]

Dammit, Don! Really? CALL girl?! iamDUMB?! Get some glasses!

OOOPPS again, sorry Chris.

 

[donjetman]

Question is, can you tell by looking at the valve cover without having to uninstall it to see if it is the new one? I see from the pics in the bulletin and the video I watched that the new one has a square opening vs an oval opening, but can you see that on the outside of an installed cover?

Thanks!

No, not from the outside.

Also, the latest version of that service bulletin is #10-06-01-008M

https://f01.justanswer.com/edhunt0r/faf4a98c-41c4-4d43-b0a1-8bbbb6775658_Engine+Oil+Consumption.pdf

 

[swathdiver]

Yup, taking care of AFM is my top priority. Probably not a full mechanical delete at this point.

Many of us were very concerned about AFM failing right after we purchased our trucks. I had it tuned out but is physically still in there. Dirty oil is AFMs worst enemy. The most common problem occurs when a VLOM solenoid gets out of time and causes a lifter to collapse. GM introduced a new and improved VLOM in 2011 which is much more reliable, they are also on their 3rd version of De-Ac Lifters too, again, very reliable.

When this system was new, the Avalanche guys were tweaking their computer systems to enhance the performance of AFM, making it run longer and such and more than a few were able to get 25+ mpg on the highway.

 

[wsteele]

So if I delete the AFM via the ECM, is the updated valve cover something I should even deal with right now? Thus far, no oil consumption since we purchased almost a month ago.

If you are not using any oil, then you likely already have the updated valve cover. By about 90K miles, I was using about 1 qt every 1K miles, original valve cover, no AFM pressure relief valve deflector, stuck rings from carbon buildup, etc. After everything was taken care of, 30K+ later, no apparent oil usage.

 

[Caligirl]

If you are not using any oil, then you likely already have the updated valve cover. By about 90K miles, I was using about 1 qt every 1K miles, original valve cover, no AFM pressure relief valve deflector, stuck rings from carbon buildup, etc. After everything was taken care of, 30K+ later, no apparent oil usage.

Well, it was driven about 1k after the 90k maintenance and about 500 by us since purchasing, so unless they were adding oil before they sold it, sounds like probably it was replaced. The original owner was in a wheelchair, so I doubt he did his own work, so more than likely when he had any maintenance or oil changes done, would have been told if low oil etc. We'll take care of AFM issue, keep up on the oil changes, and I asked my husband to check the level once a week, and that's probably about all we'll do for that issue right now. Glad the 90k was done before we bought it...saved us money and I'm sure if the dealership found anything hinky they would have tried to push the work since already in there. I got the impression the daughter who sold it was straight up and would have told us if there were any known major issues they chose to not address and probably would have dropped the price accordingly. They already dropped price pretty low from a couple dog chew damage (which look ugly, but are easily fixable; we are replacing items for about 300).

Appreciate all the info. Actually starting to understand a wee bit about the mechanics of the issues in question

 

[thompsoj22]

Well there has to be at least one "nay sayer" in this post. First welcome to arguably the most informative automotive forum on the internet. All repairs/mod's are possible with the experience, knowledge and advice from the members here. But given your last vehicle was a camry that probably would go to 300k miles with the only maint being tires, brakes and oil changes id let this one go and look for a DENALI yukon XL/ suburban with the 6.0/6.2 6spd. If you question why id put you through everything it would take to sell the one you just bought and try to find the models i advised, Than find a couple to go look at and test drive. Avoid afm/dod, Just do a search on the forum and read the challenges involved with these systems. no disrespect to those with the 5.3 4L60/4L80, Just saying if your in the $10k market you can get the bigger engine, trans, wheelbase without the afm/dod. Go testdrive the 6 litre engines.

 

[iamdub]

So if I delete the AFM via the ECM, is the updated valve cover something I should even deal with right now? Thus far, no oil consumption since we purchased almost a month ago.

Disabling the AFM should be priority. Then monitor the oil. Not all of these consume oil through the PCV system, and I believe a large factor is the type of driving it is subjected to. Lots of high RPM/high load results in higher oil pressures and higher vacuum which could make the oil coming out of the rocker squirt farther and hit the ill-placed hole in the cover (if you still have the older one). The stronger airflow in the PCV system would vacate this oil and carry it to the intake manifold. I'd still strongly suggest adding a catch can. For its benefit, minimal expense and ease of installation, it's a no-brainer.