08 tahoe with 102 k miles and Afm

[BG1988]

Try to determine what kind of oil was used in it and if the crankcase and or valve covers are sludged up inside. Reason being, we've seen so many guys on this forum but a new used truck and change the oil to synthetic. The synthetic cleans out all the sludge and causes all kinds of problems. Go slow.

it's easy to know i the engine is clean or not is floating carbon/sludge on a fresh oil change. that means you got a lot of crap in the oil pan

this is what oil looks like after 500 miles on the oil change, see Zero consumption .

You can see the clean clear oil fluid. = Zero sludge in the motor

excellent oil pressure
reading 49-52PSI hot 70-73PSI cold




High oil pressure is required for the active fuel management to work correctly
49-52PSI is the baseline for a functional Active Fuel management..
if your engine cant meet that requirement you probably should disable it...


Mind you this is low duty use.. ( we have city highway speeds 40-60mph)

I don't rev up the engine,take off and keep under 1700 rpm mostly 1100-1400rpm range.

with the 6.0L VVT
(Only if necessary then i will higher rpm it I cap my self at 2500rpm) i.e to get on the freeway you generally have to match the speed of other drivers.. that is a point when it's "necessary"




i'll take a peak under the suv to see what oil filter it has..

it would be nice for others to report there PSI and if it works correctly

so we could get an average of what works and what does not

 

[PG01]

Entire thread on oil pressure in here somewhere...

 

[harbison]

I personally recommend Tune over Range. These vehicles do consume oil. Don't rely on the Oil Life Sensor. It will let you go far too long. Check your oil and change it in order to keep this engine running. The clearances on the valve lifters are so tight that any sludge or dirt will cause them to stick when going back and forth between 4 and 8 cylinders. I have 234K on my one owner 2009 Yukon but I've had valve lifter trouble three times. The last time was while using the Range. After last job, I got it tuned and haven't had a problem for 34K.

 

[dross99_si]

2007 Tahoe LT here. Currently has 155K miles on the odometer. We had a in-person BB tune done about 3 years ago. At that time the DOD/AFM was turned off. We've had no issues thus far *knock on wood*. We did install a catch can when we first got the truck and use Mobil 1 synthetic with every 4-5k mile oil change. Haven't noticed any oil consumption issues.
Isn't a lifter collapse the major issue people face with the AFM/DOD failure? If our lifters haven't failed yet is there still a chance they could? Hoping we're in the clear on this..
For an effective mechanical delete do you REALLY have to remove the heads, change the cam, valley cover, lifters, etc?
Seems like a lot of work involved.
As far as the updated valve cover goes is there any benefit to replacing that if we have the DOD turned off or does that really only benefit people who wish to retain the DOD feature?
Thanks guys!

 

[Kraig]

AFM lifters can collapse, stick in the extended position, and it’s possible (it happened on mine) the lifter bucket allows the lifter to rotate, stick in The up position, which then allows the cam to smack the lifter love when it rotates, damaging the lifter roller and perhaps the cam. There’s also the VLOM that can fail, and perhaps other modes of failure as well.
For a mechanical delete, you definitely have to tear the top end/front of the engine down. The cam is different and has to be changed, the heads have to come off to change lifters and lifter buckets, etc.