Topic: GM Timing Chain Issues on 3.6?

[No H2O]

BTW, that GM intake manifold gasket class action lawsuit in the USA and Canada was successful and affected owners were in line for some healthy cash ..... until the bankruptcy screwed them.  Nice eh!

Well at least you can't blame GM for poor planning and not being timely. 

[sailor723]

I doubt very much it's a "clean" oil issue.  Zillion chain motors on the road with very poor oil change intervals.  This is going to be some sort of engineering issue whose cause will never be identified definitively.

I agree 100%.  I have my doubt the OLM let's the oil go so long that it could degrade a steel timing chain.  We're talking not changing the oil for YEARS.

It's not so much the chain that is wearing from a lack of oil changes, it's the guides that wear. Also the hydraulic tensioner starts to stick and then the guides and the chain really start to take a beating. We see it a couple of times a year in our shop.

Ok..so it has nothing to do with oil change intervals then.

GM seems to think that oil change intervals are involved.

Dear General Motors Customer:
This notice is sent to inform you that General Motors is conducting a Customer Satisfaction
Program that affects 2007 model year GMC Acadia; Saturn OUTLOOK; 2007-2009 model year
Cadillac CTS, SRX, STS; 2009 model year Buick Enclave; Chevrolet Traverse; GMC Acadia;
and Saturn OUTLOOK vehicles equipped with a V6 engine.

Your vehicle was designed and built to meet GM's high standards for quality and reliability.
However, we have determined that under certain driving conditions, and with extended oil
change intervals, the timing chain could wear prematurely and cause the illumination of the
Service Engine Soon light. Timing chain wear can be affected by the age of the engine oil and
driving conditions.

What We Will Do:
To ensure that your vehicle will not experience this condition, your GM
dealer will change the calibration of the engine control module, including the engine oil life
monitor, which in most cases will recommend more frequent oil changes. This calibration
change will be performed for you at no charge until February 28, 2013.

[rrocket]

WTF were the timing chains made with?  White metal??  I really want to know what the OLM change intervals are.

I suspect it has more to do with the POS timing chain quality than oil change intervals.

[articsteve]

At least they have admitted there is an issue.  However, I see that the old GM is still working at the new GM.  Blaming this design fault on the least expensive fix.

Pity those owners, original or used, that don`t have GM dealer oil changes recorded in stone if GM is gonna used incorrect oil changes as a scapegoat.

[sailor723]

At least they have admitted there is an issue.  However, I see that the old GM is still working at the new GM.  Blaming this design fault on the least expensive fix.

Pity those owners, original or used, that don`t have GM dealer oil changes recorded in stone if GM is gonna used incorrect oil changes as a scapegoat.

I have a glove box full of dealer RO's that detail my oil change history so at least that's something. (and I have powertrain warranty until October)

[Erik]

The big issue will be how GM deals with it. They really need to look after effected customers well to make sure that their history of lousy customer service is left in the past.

[Gardiner Westbound]

Premature GM 3.6 V6 timing chain failure may have been a problem since MY2005.

A redesigned timing chain was introduced to mid-2010 production, warp speed for GM.

Don't know if dealers are using the old or new chain for repairs.

Shortening the oil change interval may be an attempt to buy time and get safely past the warranty period.

[Winklovic]

Premature 3.6 V6 timing chain failure may have been a problem since MY2005.

A co-worker's 2005 CTS is having the engine replaced.  Thankfully, he bought the extended warranty.

[57 CHEVY]

Well say what you want about G.M. timing chains but many other cars have a timing belt (rubber) which HAVE to be changed at 100,000  kilometers which will cost ya anywhere from 600 to 1000 bucks a pop.

I noticed you forgot to mention the mileage at which these timing chains needed repairs!

How typical!!!

[sailor723]

Well say what you want about G.M. timing chains but many other cars have a timing belt (rubber) which HAVE to be changed at 100,000  kilometers which will cost ya anywhere from 600 to 1000 bucks a pop.

I noticed you forgot to mention the mileage at which these timing chains needed repairs!

How typical!!!

From what I've read many failures appear to be happening in the 40-60,000 mile range while others are very early and thus have been covered. The problem now is that lower mileage vehicles are getting past the 5 year warranty expiration time and owners are faced with a 3-4,000 dollar repair bill.

[my2cents]

From what I read on the GM forum I linked to earlier a couple of things stood out.

First - they reduced the size of the chain to make it quieter.

But - they also changed the engine to DI and ran the high pressure fuel pump off of the weaker chain.

Add the possibility of carbon build-up on the valves causing more stress.

It seems like they did the wrong things at the wrong time.

[articsteve]

First - they reduced the size of the chain to make it quieter.

GMs been down this road before circa 1980 ish on a 3.8 V6.

To make the engine quieter GM installed nylon sprockets.  I kid you not.  This occurred before the internet so only mechanics and ppl connected to the repair trade knew about it.  Since the 3.8 was not an interference motor and that the access to the chain case was wide open it wasn't a disaster by an measure.

[ktm525]

Want to add in piston slap on various GM small block V8s?  Gm has been producing push rod 8's for 50 years yet they still have issues? Crazy. The G8 had some cold start piston slap and the official response was: Yeah some of them do that.