Help me understand timing chain issues please

[markdjr]

I have read a lot of the threads about timing chain issues, but I don't totally understand what is necessitating the engine out replacement of the entire chain. Please correct me if I'm wrong or elaborate as needed. The issue with the earlier 3.0t engine is with the timing chain tensioners, which the TSB calls out and there is an upgraded tensioner available. The tensioner can be replaced without removing the engine, so would it make sense to proactively replace the tensioners or why can't you just replace the tensioners once they eventually go bad? Again, please explain what is necessitating the engine out replacement of the whole chain and any other relevant info I am missing. For some context, I am having timing cover gaskets replaced under extended warranty and am debating proactively replacing the tensioners out of pocket so as not to have to roll the dice down the road on whether or not the tensioners go bad while under warranty. Thanks for any info/advice.

[sepheroth86]

I think that the chains tend to wear and become loose over time.

Someone like ValpoA7 whom has done chains may have more info.

[choy188]

Coming from a c6 a6 with the 4.2 v8 that was notorious for this, what happens is the tensioners gradually start to fail, the first sign of this is on startup when you might hear a slight knocking/metallic noise, not like the sound of a failed flex pipe. Over time what can happen is it will wear down on the chain and the chain guides faster, and either the chain will stretch to the point where it can jump timing, or the chain guides can break causing the chain to also come loose as well as plastic bits being thrown around in the oil. My c7 actually had it's whole timing system replaced before I bought it. If you are having the motor out for the gasket reseal, and your car is 2013 or whatever year before they updated the part, I would probably proactively change the tensioners out but if your car already has the updated tensioner I wouldn't worry about it. I believe that the service for my car was 7-8k at audi fresno

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[markdjr]

I am having gaskets replaced, but not an engine out repair. They can do the tensioners without pulling the engine. The gasket is covered by warranty, but they won't do anything proactively, so tensioners would cost me around $600-700 out of pocket.

[gk1]

I am having gaskets replaced, but not an engine out repair. They can do the tensioners without pulling the engine. The gasket is covered by warranty, but they won't do anything proactively, so tensioners would cost me around $600-700 out of pocket.

If they are going to only charge $600-$700 to do the tensioners then jump on it.
It is a several thousand dollar job. ($4145 to be exact). The parts are cheap, but the labor is very high.
They were still revising the tensioners up until at least 2016 under TSB 2039995/2 and then even the parts mentioned in that TSB were superseded again.
So you know they never really figured it out properly with 7+ revisions.
AFAIK this is the latest revision.
Bank 2 - 06E109217AM
Bank 1 - 06E109218AP

GL

[bahula03]

Short answer- I agree with gk1 that if you've got a MY12-15, it's a good do it while you're there.

Long answer- people seem fond of conflating 3.0T tensioner issues with various other VAG tensioner issues, as well as conflating the startup rattle (which is what the TSB is for) with actual tensioner failure. The tensioners in the 3.0T don't have a history, to best of my knowledge, of catastrophically failing or otherwise causing the car not to run properly. The fear with the rattle is mostly that there'll be enough slack for one of the chains to jump time, and partially that the time the chains spend "un-tensioned" will accelerate wear (primarily stretch) of the chains. Not that this forum or my reading is exhaustive, but I think I've heard of one 3.0T in an SQ5 skipping time. Likewise, there's not a ton of evidence of rattle-causing tensioners accelerating chain stretch. Valpo's car tends to be the easy example, but that's a single car with over 200k miles ¯\_(ツ)_/¯ Once you get into high mileage IMO, it gets tough to say whether the tensioners caused the chain stretch or if it's just the normal stretch inherent in timing chains. Which gets around to the age old question- how much stuff do you want to fix that isn't broken?

[choy188]

Short answer- I agree with gk1 that if you've got a MY12-15, it's a good do it while you're there.

Long answer- people seem fond of conflating 3.0T tensioner issues with various other VAG tensioner issues, as well as conflating the startup rattle (which is what the TSB is for) with actual tensioner failure. The tensioners in the 3.0T don't have a history, to best of my knowledge, of catastrophically failing or otherwise causing the car not to run properly. The fear with the rattle is mostly that there'll be enough slack for one of the chains to jump time, and partially that the time the chains spend "un-tensioned" will accelerate wear (primarily stretch) of the chains. Not that this forum or my reading is exhaustive, but I think I've heard of one 3.0T in an SQ5 skipping time. Likewise, there's not a ton of evidence of rattle-causing tensioners accelerating chain stretch. Valpo's car tends to be the easy example, but that's a single car with over 200k miles ¯\_(ツ)_/¯ Once you get into high mileage IMO, it gets tough to say whether the tensioners caused the chain stretch or if it's just the normal stretch inherent in timing chains. Which gets around to the age old question- how much stuff do you want to fix that isn't broken?

Mine jumped time and threw a code according to the paperwork, wasn't under my ownership at the time though

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[xanmato]

Jumping time is super rare from a tensioner with a simple startup rattle, because after the oil pressure builds up, the oil pressure takes over as the main force of applying tension and functions as normal. I don' think there is enough centrifugal force on the chain during startup to actually jump unless your chain is already stretched quite a bit. I would put my money on a chain jumping from getting a broken off piece of the plastic guides getting jammed on a gear. With a lower mileage engine and a short rattle I wouldn't worry about it. Keep tabs on the rattle duration, but otherwise its statistically fine.

What's lame is that 'revised' tensioners still fail, my CREC has a startup rattle if let to sit for 3 or more days. If Audi would have redesigned them with the ratcheting ring pawl like the 2.0T we probably wouldn't have this issue.

[Valpo A7]

The cam tensioners will wear out and the hydraulic function of them will wear over time allowing some slop in the upper chains. The cold start rattle is that evidence. Once it gets advanced enough you will get a P0016 and P0018 timing code which is the crankshaft speed and left/right cam speed are off from each other. From what I understand its an interference engine so getting far enough off will have expensive consequences. There are a couple of plastic guides that tend to break on the upper tensioners as well which causes problems as well. Here a re few pics of my broken guides.

BROKEN GUIDES.jpg upper guide.jpg sude guide.jpg


When I did mine I opted for an engine out repair and replaced all 4 chains. I found that all 4 of my chains exhibited some amount of stretch, just not sure if it was stretch beyond spec. I was also at 204,000 miles roughly. 1 of my lower chains was sloppy enough that it ate into a tensioner as well. Pic of chain stretch, chewed tensioner, and a full view of all the chains. Since I went full hooah on the repair I opted for all new guides and chains, no reason to put an old chain back in.

engine 6 (2).jpg MAIN CHAIN STRETCH.jpg CHEWED TENSIONER.jpg


If your engine has cold start rattle then push like hell for them to replace the tensioners as they are failing. And like GK1 said, if you do have to pay for them that price is a steal. The price for just the 2 tensioners is over $300. Tell them new cam bolts as well since those 4 little shits are stretch bolts. 80 Nm + 90* turn. BTW, there are no gaskets to change on the cam covers, its RTV. Get an oil change done as well since it will be hard to keep RTV bits from falling into the engine no matter how hard they try

[Burkeomatic]

For 600-700 I would jump on it. When I bought my car, it had a little bit of a warranty. I bought the car sight unseen from carvana, and it was warm when I got it to test drive it. My car had about 52k on it, and it had a terrible chain noise, and it threw a P0016 probably a few days after owning it. The warranty covered the repair, which would have been about $4k. Now I have a low mileage car where I know the chains are good. There doesn't seem to be a specified mileage where the chain start going out. I have seen lower mileage like mine, or last tons of miles like Valpo. I am not sure how long my car would have soldiered on before something serious happened, but I am glad I have all of the updated stuff on it now.

[choy188]

For 600-700 I would jump on it. When I bought my car, it had a little bit of a warranty. I bought the car sight unseen from carvana, and it was warm when I got it to test drive it. My car had about 52k on it, and it had a terrible chain noise, and it threw a P0016 probably a few days after owning it. The warranty covered the repair, which would have been about $4k. Now I have a low mileage car where I know the chains are good. There doesn't seem to be a specified mileage where the chain start going out. I have seen lower mileage like mine, or last tons of miles like Valpo. I am not sure how long my car would have soldiered on before something serious happened, but I am glad I have all of the updated stuff on it now.

Mine went at 75k

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[bahula03]

Mine jumped time and threw a code according to the paperwork, wasn't under my ownership at the time though

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For the sake of discussion and sharing info, what were the symptoms (was it just the code?), and what'd they replace?

[Valpo A7]

For a full engine out replace the timing chains I have seen as much as $10,000 from the dealer. I was quoted $5,000 from an independent shop to do the work, I have seen others say $6500.

I bought most of my parts from FCPEuro and then missing items from the dealer. I also picked up a set of motor mounts and I would guess I dropped about $2,000 in parts. I needed a few specific tools as well that will probably never be needed unless I do this job again, but otherwise the tools I picked up I will use quite a bit.

[choy188]

This was the paper I found in my glovebox

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[Burkeomatic]

For a full engine out replace the timing chains I have seen as much as $10,000 from the dealer. I was quoted $5,000 from an independent shop to do the work, I have seen others say $6500.

I bought most of my parts from FCPEuro and then missing items from the dealer. I also picked up a set of motor mounts and I would guess I dropped about $2,000 in parts. I needed a few specific tools as well that will probably never be needed unless I do this job again, but otherwise the tools I picked up I will use quite a bit.

I went to an indy shop who wasn't a euro specific one but were in the repair network, and they billed my warranty company $4500, which included PCV replacement. However, I wish I had taken the car somewhere else and had a copay as they had it for damn near 3 weeks. I thought mine seemed low compared to what I had read on here though.

[Valpo A7]

This was the paper I found in my glovebox

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This is a very good list of parts for future reference. Based on prices I would say they got the OEM parts for the most part. The 4 chains at the top look like OEM prices while you can get IWIS chains from FCP for less than half that price. I want to say that IWIS are actually OEM without the OEM packaging. The 2 adjusters for $560 each were probably not needed but if it was a warranty job then no big deal. FCP lists them for about $500 each.

[choy188]

This is a very good list of parts for future reference. Based on prices I would say they got the OEM parts for the most part. The 4 chains at the top look like OEM prices while you can get IWIS chains from FCP for less than half that price. I want to say that IWIS are actually OEM without the OEM packaging. The 2 adjusters for $560 each were probably not needed but if it was a warranty job then no big deal. FCP lists them for about $500 each.

Mine was done at an audi dealer so I at least have that 1 year warranty

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[cuerna]

Does anyone know how to check timing with obd11, ??
I believe is the block 93 under the engine control unit.