jr_ece

Just lost my 2001 Suburban 5.3L 4x4 LT Autoride in a total loss accident. Loved it and had few problems with it. Started looking at newer model Suburbans (2008 - 2012) and found several forums including this one that put fear in me with the Chevy Active Fuel Management (AFM) and oil consumption. It sounds like AFM is causing oil consumption with several seeing the consumption go away after disabling AFM. But the referenced GM TSB starts with valve covers, oil deflector, new lifters, pistons and rings, and finally engine replacement with each new item being a new stop at the dealer. Other places I've read there is piston and ring to sleeve tolerances causing the oil consumption. What a mess! I'm very nervous about buying a newer Chevy with AFM to say the least.

Assuming I can get advice on how to safely buy one of these, I'm looking at two Suburbans (see below) and would like some input from anyone that can impart some wisdom.

2009 Suburban LTZ 6.0L L76 variable cam phasing with AFM, 70k miles
2009 Suburban LTZ 5.3L LY5 with AFM, 75k miles

The 6.0L has a definite tap, tap, tap sound that can be heard all the way to the back of the vehicle (lightly) after it's ran for 3 or 4 minutes and beyond. When I checked the oil it was fairly dark and 1 quart low. There is no window sticker or recent history stating when it was changed. Carfax does show an oil change at a dealer roughly 7k miles ago. If the oil has really not been changed since then I'm okay with 1 quart low, but I'm very concerned about the tapping noise. I asked for the oil to be changed to see if the tapping noise changed with fresh oil. It did not make a difference as far I could tell.

The 5.3L does not have a tapping noise at any time while running. The oil is somewhat dark and 1 - 1.5 quarts low with right at 3k miles on it. Sounds like it is border line for over consumption, and it's consuming more oil than my 2001 5.3L with 157k miles.

The higher mileage on both trucks bugs me since several of at least the 5.3L engines have developed problems in this mileage range.

Can anyone provide things to check or look for to see if I'm headed down valve cover, deflector, lifter, piston/ring, and new engine lane with buying one of these trucks?

Is better to buy newer years? From what I've read it doesn't make much difference. This issue is showing up as new as 2013 according to one post.

If I buy one of these trucks what are the first steps to take to try and prevent the GM AFM TSB fiasco?

What about the following products? I'm assuming they both decarb. Does this prevent or stop oil consumption? If so, does it in turn prevent going down the valve cover, deflector, lifter, piston/ring, and new engine road? Seems like the issue is bigger than just decarbing often, but maybe not...
- Seafoam - never used before ??
- Auto-RX (http://www.auto-rx.com/) - never used before ??

I want my 2001 back!

I've read about this topic for quite a few hours over the past week. I'm pretty sick over losing my non-AFM truck. I'm now a VERY disappointed GM only owner that for the first time might be looking over the fence at other manufacturers.

Thanks in advance for any help you can provide.

JR

markshop

I too am concerned. I bought a new 2013 Tahoe and also worried about the afm. Are there any high milage 07 -13 without oil consumption problems or are they all affected?

jr_ece

@Markshop - From piecing info together the TSB road (replacing valve covers through new engine) is probably not required by most. I'm thinking about 20% go down some portion of the TSB road. This is a big guess on my part. I'll bet the oil consumption problem is a much higher percentage of engines, but the damage is light enough to not require repairs. Driving and/or maintenance habits appear to greatly affect the damage. I'm hearing you should change the oil every 3k miles no matter what kind of oil is used and completely ignore the oil life monitor. Performing an aftermarket tune to disable AFM appears to be the ultimate fix, but can void portions if not all of the 5yr/100k mile powertrain warranty.

JR

jr_ece

anyone?

Joe In NY

sorry for your great loss our 2007 is nothing compared to our 2002. I feel you will be disappointed in the newer LTZ's. But. I have an oil consumption around 1 quart per 1500 miles. But my burb has had sooo many problems since 96K.

Really I cant recommend the newer ones much at all. Too disappointed. As many problems as my brothers 2009 Expedition has I prefer it over my burb sometimes. I have to say the expedition has more comfy seats, smoother ride, and much quieter on the highway.

Our 2002 was even better than the expedition and the newer burbs all around...

Cant help you...