Strategies for Preventing Timing Chain Stretching (Wear): what can we do?

[philthy]

Originally Posted by PieNsky

I don't recall the mileage, ballpark for me was 117-119,000 . A little over half were with full synthetic . The rest with traditional oil changed when the DIC algorithm indicated it to be changed. Most of my miles were of an hours drive on the interstate . Haven't a clue why mine lasted so long. I suspect short drives hasten the stretch, along with low oil.

Mine definitely was not low oil.....watch mine like a hawk. My wife's on the other hand Both vehicles use traditional oil, not synthetic.

Short drives could apply, both of us work within 3 miles and kids school and activities are all within that radius as well. Her vehicle gets used for the occasional long distance travels. Never thought of the low mileage trips playing into it.

[Car_Almond]

The more we here from people and I look into this, the more I think its simply bad timing chains material. They added a surface hardening procedure (carbonitriding) in July 2010, and the timing chain had to change part numbers as a result. Remember this basic family of V6 engines have been manufactured all the way back to 2003, and direct injection was on some of them and not on others. In a nutshell, some of the worst failure rates are in the big SUV Lambda applications (traverse, acadia, enclave, outlook) and many of those had port fuel injection. The chains may have bad oiling feeds, as some Nissans, GM Opels, and Mitsubishis have suffered from this over the last 15 years, so we can't rule that out in this case.

[Car_Almond]

Notice the latest LFX version of this engine family has been modified for twin turbochargers in the latest Cadillac, to make 420 HP, fully 100 more than our Camaros make. I guess GM had to beef up the timing chain on that one! That thing might even have an oil cooler, hope so anyway. Wish we had that beast in our Camaros, huh?

[TooCool5]

I understood the LLT's were produced in two locations. Canada and somewhere else south of the border with different suppliers.
Just a faint memory from other threads.
Its a weak design with half tooth sprockets for noise control. the original chain design was more robust on the 3.6.
As far as PTFE the license is owned by Dupont I think, if you use half of any additive you should be OK.
I knew of a racer that had it in his engine and blew out the oil pan, the engine kept running without seizing without any oil in it.
I wish my chains would go out while on warranty but i don't see that happening in the next 10 months with the low miles I drive.

[KMPrenger]

Originally Posted by Car_Almond

An interesting fact to be revealed from the techie-geek discussion at LLT V6 Timing chain wear web link ...was the fact that in the future, a special timing chain ASTM standardized test will be added to the GF-6 test suite (GF-5 does not have it). In the future, all oil having a GF-6 rating will have had to pass this performance test.

I've read the first 5 or 6 pages there, and I must say I thought some of it was pretty interesting stuff. I just want to say ( I think for everyone here) I appreciate you looking into this like you have and starting a discussion with another group that could potential help us out.

Originally Posted by Car_Almond

Notice the latest LFX version of this engine family has been modified for twin turbochargers in the latest Cadillac, to make 420 HP, fully 100 more than our Camaros make. I guess GM had to beef up the timing chain on that one! That thing might even have an oil cooler, hope so anyway. Wish we had that beast in our Camaros, huh?

Yep, that engine while being basically like an LFX, has a lot of the internals swapped out for stronger stuff so that engine should be pretty stout. I can't remember if chains was on that list or not. I feel that engine has plenty more in it than just 420HP and 430 TQ.

[Car_Almond]

Originally Posted by KMPrenger

.Yep, that engine while being basically like an LFX, has a lot of the internals swapped out for stronger stuff so that engine should be pretty stout. I can't remember if chains was on that list or not. I feel that engine has plenty more in it than just 420HP and 430 TQ.

Lets be the first to put one of those Cadillace LFX turbo 420 HP monsters into a Camaro!!

[Car_Almond]

Originally Posted by KMPrenger

I've read the first 5 or 6 pages there, and I must say I thought some of it was pretty interesting stuff. I just want to say ( I think for everyone here) I appreciate you looking into this like you have and starting a discussion with another group that could potential help us out...

The search for a solution has been difficult. Some insight, fun to learn about engineering those things, yet largely failed to deliver some kind of way to get those chain link/pin interfaces better oil. I did put a half dose of Lubro Moly MoS2 (NAPA parts store) in there, yet now I'm thinking it may be hard to beat that highly-engineered Pennzoil Ultra 5w-30 SN/GF-5/dexos1 straight, no additive needed. My fav oil so far.

Maybe a GM inside-engineer will wiki-leak-style get us the info and hide their identity. Like, I wonder if the oil holes feeding the chain are really too small, or the oil jets aimed at the chain get misaligned? (This kind of thing has happened on a few Nissan, Mitsubishi, and GM Opel engines in the last few years.)

[ChadG]

Originally Posted by Car_Almond

Lets be the first to put one of those Cadillace LFX turbo 420 HP monsters into a Camaro!!

Somehow I don't see this happening because of the different ECU - but it would make me very happy!

[stevey_frac]

Something that might be enlightening, would be to do a used engine oil analysis at various points along the OLM scale. Doing an OCI at 80% remaining, 65%, 50%, etc.

If the oil is running out of spec on base number, acid number of ZDDP, or something else, that might explain the cause of the problem. I can get this done on my next oil change, though, that won't be for another few months.

[Car_Almond]

Originally Posted by stevey_frac

Something that might be enlightening, .....though, that won't be for another few months.

Did GM ever issue a recall to re-program the on-board engine computer unit (ECU) for shorter length oil change intervals (OCI) for 2010 Camaros? I can tell you that 2011 Camaros like mine came from the factory with super short OCIs, very annoying. Note 2007 and 2009 Lambdas (Traverse/Enclave/Acadia/Outlooks) were recalled for shorter OCIs.

[TooCool5]

Originally Posted by Car_Almond

Did GM ever issue a recall to re-program the on-board engine computer unit (ECU) for shorter length oil change intervals (OCI) for 2010 Camaros? I can tell you that 2011 Camaros like mine came from the factory with super short OCIs, very annoying. Note 2007 and 2009 Lambdas (Traverse/Enclave/Acadia/Outlooks) were recalled for shorter OCIs.

Yes, 2010 had an ECM reflash that changed the OLM.
Though not a re-call dealers updated this anytime you brought
your Camaro in for service.

[ChadG]

Originally Posted by TooCool5

Yes, 2010 had an ECM reflash that changed the OLM.
Though not a re-call dealers updated this anytime you brought
your Camaro in for service.

What he said - it wasn't a recall just a covert fix.

[shrinkdoc]

Looks like nothing we can do. Weare at the mercy of GM. I just read an article today on the 2014 Caddy that has the twin turbo 3.6 putting out 420hp and 420lbs of torque. Obviously they must have fixed it by now. I can't see them jeopardizing that setup with a known timing chain problem. Just wish they would tell us what the fix was.

[United_727]

I change mine once a year . I only drove it ~ 400 miles this past year. Mobil 1 and a PF2129,hoping for the best.