timing chain failed? cost? - 2006 A6 Avant 3.2 v6

[Tom Bailey]

Hi I have a 2006 3.2 A6 Avant (90k miles) and i think the Chain has gone. My wife started it up on Friday morning, and I could hear a loud rattling so she turned it off. I tried to restart but no luck and sounds pretty unhealthy.

question is, if the chain has broken and the engine turned (RAC man came out and tried it too) what kind of cost am i looking at to repair at an independent? I am guessing it isnt going to be worth it? what i can see on the net is that it is an engine out job and seems like labour is going to make it not viable to fix? Has anyone actually had it fail and fixed it?

thanks, Tom

 

[Sverige]

Commiserations Tom. My car has the same engine and I've been researching the issue of late, as it seems it might be possible to buy some extra life by replacing the upper chain tensioners if you catch the issue early enough.

Did your engine rattle on startup, or did it happen out of the blue? 90k seems young for a chain to break unless it was rattling for a while before. I wonder if it would be worth approaching a main dealer and claiming it's unreasonable for a cam chain to fail at such a low mileage and that it's a latent defect. Worth a try if it doesn't cost you anything but might save £1,000s??

From what I've read, chain replacements will cost you £2,500-£5000. I've seen 27-30 hours labour mentioned, so multiply that by your favourite Audi specialist's hourly rate and add £900 parts (chain, upper and lower tensioners) for a rough estimate. Hope you can post back with an update if you get a quote. Have you been changing the oil yearly or a bi-annual "long life" schedule?

 

[Tom Bailey]

thanks for the note, frustratingly I have had it serviced regularly at Brighton Audi main dealer since i got it, so for past 5 years or so but this year i decided to use local Halfords autocentre for MOT/Interim service etc... as it was across the road from work, and that was only a month back (7th June)!

I hadn't noticed a rattle before hand, i drove it home the night before and didnt notice anything odd, and then i heard quite a bad rattle from inside the house when she started it in the morning (kitchen window was open). then it wouldnt start again.

one thing that is bugging me is that the engine check light has come on intermittently over the past few years, and I asked Audi about it each time i took it in but i dont think they ever found out what it was. Could it have been the cam tensioners failing or at least prompting a fail which was never discovered by audi but in the end resulted in the chain failing.

Havent actually had anyone knowledgeable look at it yet, I have a local Audi independent near my my house but he is closed till tomorrow, so going to get him to check it over.

 

[Sverige]

From what I've gathered, reading up on this on a few forum threads in various places, the failure mode seems to begin with the tensioners not maintaining tension overnight, as the oil drains from the pistons in them so on startup you might hear a rattle until the oil pressure builds and re-establishes the Tension. At this stage it could be fixed with new upper tensioners with engine remaining In situ (Edge Motors on YouTube has a video how-to).

Left untreated, the chain will gradually stretch from the slack tensioned starts to the point the engine check light may come on and there may be a rattle noticeable during normal running. At this point the chain could be loose enough to skip and put the engine out of time, which may still be the problem with yours, rather than a broken chain.

Chain and tensioner replacement plus perhaps some bent valves to replace seems likely, but please get more knowledgable input than mine.

I'm surprised your main dealer wasn't onto this early, as they can check via engine diagnostics to see if the "block 93" values in VCDS are beyond 8 degrees per bank, or at least if they are rising over time, which indicates a lengthening chain.