GM 2010-12 3.6 LLT timing chain fixed ?

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Is timing chain issue resolved on this engine , or, is it still happening ?
Did they change something in the engine from the previous LY7 that fixed it ?
Point me to it in writing if you can.

Was questioning why timing chains are being sold for this generation engine already. Being it has only been out for 2 years.
 
Don't know if there was anything inherently wrong with the timing chain, but I believe premature timing chain failures are what prompted GM to recall cars to recalibrate the oil life monitor.

It seems the OCI the monitor suggested was not consistent with long timing chain life, so the algorithm was tweaked to require more frequent changes.
 
Our GM product rep said that the failures where due to the oil breaking down more rapidly than anticipated in the direct injected engines. He explained that GM anticipates a shift toward turbos and direct injection to meet café regulations and thus, the preemptive move to a synthetic-blend (Dexos) and the recall to recalibrate the OLM more conservatively.
 
Originally Posted By: apwillard1986
Our GM product rep said that the failures where due to the oil breaking down more rapidly than anticipated in the direct injected engines. He explained that GM anticipates a shift toward turbos and direct injection to meet café regulations and thus, the preemptive move to a synthetic-blend (Dexos) and the recall to recalibrate the OLM more conservatively.


I've heard the same thing.

One would think GM would of figured that out before releasing them to the public.

I have an '09 Traverse, and I did get a letter that they were extending the warranty on the timing chain, to, if I remember right, 10yer/100,000 miles.
 
I think the late '10 production got revised chains. So the '11-'12 are fine. I think GM used about 4-5 chain designs over the previous years plus software updates. But the '11 and newer are not having chain issues. The warranty should be at least 5 years/100k miles and if makes it through the warranty then you've pretty much determined the timing chains are going to hold up.
 
Originally Posted By: MarkM66


One would think GM would of figured that out before releasing them to the public.

I have an '09 Traverse, and I did get a letter that they were extending the warranty on the timing chain, to, if I remember right, 10yer/100,000 miles.


Better than the old days of waiting 10 years to revise those intake failures GM suffered. Every car maker(Asian/Domestic/Euro) has their problems and they all sort them out pretty quickly now.
 
Originally Posted By: MarksCol
Is timing chain issue resolved on this engine , or, is it still happening ?
Did they change something in the engine from the previous LY7 that fixed it ?
Point me to it in writing if you can.

Was questioning why timing chains are being sold for this generation engine already. Being it has only been out for 2 years.


Parts availability does not directly correlate. Doesn't really tell you anything. Oil pumps are available too and they don't seem to fail.
 
Originally Posted By: apwillard1986
Our GM product rep said that the failures where due to the oil breaking down more rapidly than anticipated in the direct injected engines. He explained that GM anticipates a shift toward turbos and direct injection to meet café regulations and thus, the preemptive move to a synthetic-blend (Dexos) and the recall to recalibrate the OLM more conservatively.



The reprogramming of the OLM is true and there is a bulletin and recall to perform this service.

HOWEVER - it did not fully solve the issue. Case in point..my dad and I each have 2008 CTS's with the 3.6DI. He always went by the oil life monitor with 10-12k mile changes. His chains needed replacement at 41k miles. I, on the other hand, always change my oil at 5-6000 miles and at 72k miles I had the light come on and go off briefly 2x (with the chain code)telling me the chains are probably gonna be due changing sometime in the near future. Since GM is covering these for 10yrs and 120k miles, I am not too concerned right now. My point is, long or short oil changes do not prevent the failure but only extends it.
 
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They once had a great 3800 V6 that would get 30 MPG HWY in a Buick LeSabre.

It would go for 200,000 miles with regular care.

Sometimes evolution is not good.
 
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I just don't like the idea of V-6 engines with chain driven OHC. It ends up being a complicated mess with multiple chains. Dodge had a good belt driven 3.5, and belts are easy on that engine to replace and last over 100K miles. Now their new Pentastar 3.6 is chain driven like the GM.
 
I thought the problem was with the plastic chain tensioners, and not the chains themselves?

But yes, the OLM was way too optimistic with the GM-6094 oil spec and it was being loaded up with fuel dilution and not protecting the plastic guides from the metal chains. The solution was two-fold: dexos1® spec oil and knocking down the OLM to a more reasonalble interval.
 
Originally Posted By: threeputtpar
I thought the problem was with the plastic chain tensioners, and not the chains themselves?

But yes, the OLM was way too optimistic with the GM-6094 oil spec and it was being loaded up with fuel dilution and not protecting the plastic guides from the metal chains. The solution was two-fold: dexos1® spec oil and knocking down the OLM to a more reasonalble interval.


I heard the chains, but I'm not really sure what the true problem is. As in, what's the difference between the new chains, vs the old chains. Or the tensioners, if those were the issue. I'd like to know..
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