THE Timing Chain Tensioner Failure Thread

[Allowencer]

I'll add to this mix.

I called a very reputable shop in my area called C's Autohaus, that everyone I know that owns a VAG/BMW/Mercedes car takes their cars to, and asked them about replacing my timing chain. They told me that as long as the tensioner has been replaced with the updated one (mine was when the oil consumption service was done and pistons/bearings were replaced as well as chain guides,) that they do not feel the chain needs replaced at all. They have several of these cars in the 160k+ miles range that they regularly service, and they said they've never needed to replace a chain on any of these motors as long as the tensioner is updated.

They could have easily told me to bring it in and take my money, but they went as far to say that they felt I'd be wasting my money if I did it, but they'd happily do it if I insisted on having it done.

It seems you will always find differing opinions lol. Not sharing to purposely add to confusion... just throwing this in to offer another perspective.

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This is true to an extent. However, if you are upwards in mileage, I'd say anywhere from 90-100k+, do yourself the favor and replace EVERYTHING in there. Guides, chain, you name it. Do the balance shaft chain circuit as well. Look at the pics I posted, it stretches and that causes more slack and strain on the whole motor. Perfect example, sorry blbroo, but look at his engine, he replaced only the tensioner. Look how far out the tensioner's piston has to extend to provide proper tension on the circuit. Once it hits it's limit, there's no more capacity to provide tension. That means the chain will forgo added stress and will break. If you have modified the driveline in any fashion - don't cut corners and swap the chain. You own an Audi, don't do maintenance on it like you would a beater.

In addition, there is a newer chain; it has been revised. It has been proven to wear / stretch less.

2009 with 60k miles. No start, tried twice. Pulled code and got P0016. Happened just after I failed the stage 2 oil consumption test. Car is TD1 and they are refusing to cover it.

Took it to independent shop, they pulled the upper cover off and this is what they saw:





As you can see, the chain is actually sitting on top of the teeth.

Shoo will replace the parts and re-time. Then they'll perform a leak down test to see if any of the valves were damaged before pulling the head. Wish me luck...

^^^^^

Ouch. They should try to safely identify how far off timing occurred. If you are 1-2 teeth off, you will more than likely be OK. Good luck man.

That is scary! Ok, guys. I am at 46k miles and no tune. Can i change out the tensioner and leave the belt? Chain shouldn't stretch unless it is put unload higher then normal loads right?
Actually, what is causing the chain to stretch? If the tensioner gets loose over time, shouldn't relieve stress on the chain?

At 46k, you're good to just swap the tensioner.

The chain will naturally stretch over time. Modifying the driveline only increases the impact on the chain and the additional strain which will cause it to further stretch. As I mentioned previously, the newer chain is a revised one which will stretch a lot less.

You can change out the tensioner and leave the chain and not replace it. My recommendation is if you're in there already you may as well replace the chain too while also inspecting the guides. If you decide to only swap out the tensioner you'd still be fine for many more miles, I just prefer to do preventative maintenance like that if I'm already in the middle of a job anyway.

The chains will stretch over time even with the natural, designed stress of the system. In my case, I had 130k miles when I swapped everything and the "stretch" on my chain was fairly minimal when comparing it to the new one I put on.

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I mostly agree with what skywalker said; however, I still stand by replacing all of the components in the circuit, especially if you intend on keeping the car. I would concur that by just replacing the tensioner you will get more miles out of the chain, but how much? 20k, 50k? 75k? Under what type of load? Those are all factors / variables I'd rather not dance with and just do the job right the first time.

There was significant stretch on the chain when I did mine. Keep in mind, any stretch beyond 5mm is considered significant'. You can also measure this at the top once the chain is installed. I show how to measure that in my build thread.

I spoke with my dealership in Toronto yesterday about this. First off, they told me that the whole front end needs to be removed for them to inspect....... after I told him that they could look through the inspection hole, they said they'd call me back...then called and restated the front end needs to be taken apart. Might need to look into changing dealerships...

An they quoted me $1500 to do the job.

I woulda LOL'd in their face. That's a dealership that only does things by the book and nothing else. Rookies.