2011 Tahoe what to look for

[iamdub]

The 2011 should have the latest updates GM made for the AFM system- updated AFM lifters, updated VLOM, updated valve cover and shield on the relief valve. Still, I recommend disabling it while it's still 'good' to prolong the life of the mechanicals. You won't miss the ~1 MPG loss. You can get the Range plug-in device or, better yet, get a full custom tune to not only disable the AFM, but clean up the messy factory trans and throttle tuning. It'll make it much more responsive and predictable and prolong the trans life. I see such a tune as a longevity measure and the performance increase is a side benefit. Drive easily and you may even get back any fuel mileage lost from disabling AFM or even get better mileage.

As the others said, listen for the compressor at startup. If you don't hear it, it's probably locked up. If it's locked up, it's probably because the air sleeves on the shocks are blown. The blown sleeves are obvious when you look at the rear shocks. If needed, you can repair the system for around $600-$1000. Or, you can delete it/bypass it with standard shocks for a fraction of that.

At 150K miles, you shouldn't have any major oil leaks. At least, nothing wet. Some grime from a very slow leak would be acceptable. But nothing dripping. Points to check are where the engine meets the trans bellhousing. There's a small half-circle notch (about 1/8") at the very bottom where oil would be leaking from if the rear main seal was leaking.

I can't speak much on rust cuz I don't deal with that.

When you go look at it, take pics and post them up to go along with any questions you may have.

 

[CaptainAmerica1]

For longevity it’s an absolute must that you disable the AFM. It’s not a matter of if it’s gonna fail, it’s a matter of when.

 

[avalonandl]

If the rear air shocks are original they are blown. The only way to tell is to get it up on a lift and you will see the rubber bags have holes in them. The sleeves on the rear shocks is what i mean.

 

[ddann19]

For longevity it’s an absolute must that you disable the AFM. It’s not a matter of if it’s gonna fail, it’s a matter of when.

If the rear air shocks are original they are blown. The only way to tell is to get it up on a lift and you will see the rubber bags have holes in them. The sleeves on the rear shocks is what i mean.

Is the front and rear both air ride? I am only finding additional information where they are talking about replacing the rear air ride suspension. Does the rear fail sooner or more often?

 

[ddann19]

The 2011 should have the latest updates GM made for the AFM system- updated AFM lifters, updated VLOM, updated valve cover and shield on the relief valve. Still, I recommend disabling it while it's still 'good' to prolong the life of the mechanicals. You won't miss the ~1 MPG loss. You can get the Range plug-in device or, better yet, get a full custom tune to not only disable the AFM, but clean up the messy factory trans and throttle tuning. It'll make it much more responsive and predictable and prolong the trans life. I see such a tune as a longevity measure and the performance increase is a side benefit. Drive easily and you may even get back any fuel mileage lost from disabling AFM or even get better mileage.

As the others said, listen for the compressor at startup. If you don't hear it, it's probably locked up. If it's locked up, it's probably because the air sleeves on the shocks are blown. The blown sleeves are obvious when you look at the rear shocks. If needed, you can repair the system for around $600-$1000. Or, you can delete it/bypass it with standard shocks for a fraction of that.

At 150K miles, you shouldn't have any major oil leaks. At least, nothing wet. Some grime from a very slow leak would be acceptable. But nothing dripping. Points to check are where the engine meets the trans bellhousing. There's a small half-circle notch (about 1/8") at the very bottom where oil would be leaking from if the rear main seal was leaking.

I can't speak much on rust cuz I don't deal with that.

When you go look at it, take pics and post them up to go along with any questions you may have.

thanks i’ll do that. any thoughts on spending a little more to get down in the 100k mike range or save a little and stay up at 150k miles?

Basically, am i going to be needing to do the same work at either if those miles!?

 

[PG01]

A 2012 -14

 

[wjburken]

Is the front and rear both air ride? I am only finding additional information where they are talking about replacing the rear air ride suspension. Does the rear fail sooner or more often?

Only the rear have airbags. It is part of the auto-leveling system. The front and rear have electronically control shocks that adjust to modify the ride based on conditions. You can delete the Auto Ride while keeping the auto-level or delete both.

 

[iamdub]

thanks i’ll do that. any thoughts on spending a little more to get down in the 100k mike range or save a little and stay up at 150k miles?

Basically, am i going to be needing to do the same work at either if those miles!?

It really depends on how well it was maintained. 100K or 150K doesn't mean much on these things. Generally speaking, if all was well maintained and the truck wasn't abused, then the 100K would put you a little ahead as far as expected required maintenance and repairs. But, a 150K unit may be in just as good of condition or better if the owner has already replaced parts. So, you can't just shop by mileage. The electronic/active suspension components seem to fail around 80K on average. The AFM stuff seems to be in the "questionable" zone around 125K-200K, but this is a very generalized statement. The key to keeping the AFM system alive is keeping clean, quality oil. Do NOT go by the Oil Life Monitor. It'd be ideal if you could look under a valve cover of a vehicle you're interested in. That would give you a pretty good idea of how well it was maintained.

 

[Doubeleive]

you can reach up under the rear wheel area and squeeze the rear air shock bladder with your hand _(before you start it) it should be firm like a balloon, if it is blown out it is easy to tell.

 

[Hrocks]

If it's a clean and well maintained vehicle, I would just do your typical used car due diligence. The GMT900 platform was IMO, the best series that GM produced. The 2kXX platform seemingly finally got the bugs worked out now that they're on their last legs. I have a 2010 LTZ that my son's been driving for the past four years and it continues to be great.

Having stated that, the only "problem" areas have been few:

• Rear window defogger connector has plagued this series.
• water can collect in rear doors if weep holes get blocked--remove rubber drain plugs

I honestly can't really think of any AFM issues that seem to be a hot topic, nor any other perplexing problems. Mine has about 120k on it and it still runs and looks fantastic. I very recently bought a tune up kit, just because.