How to check timing chain on 2012 A4

[Ethenski]

So I recently purchased a 2012 A4 Premium Plus with 104k miles on it. It seems like it was well taken care of, very clean and mechanically sound (aside from a vibration at 58mph?).
I was wondering how I can check to see if the timing chain has been replaced or needs to be replaced, as I've heard that it's a problem on these cars.

[Theiceman]

https://www.audizine.com/forum/showthread.php?t=805102

Sent from my SM-G973W using Audizine mobile app

[smang]

Can see both cam gears + some timing chain by taking off the upper timing cover. If you know what to look for you can probably tell if it's been replaced. If you want to see all the guides and tensioners you'll have to take off the front bumper and radiator, then the lower timing cover needs to be replaced once opened up. Best method is to look through service records lol. I think the tensioner is the real problem on these cars, not timing chain correct me if I'm wrong.

Also AFAIK that vibration is a mystery problem that some of these have. If getting your wheels balanced doesn't fix it you may end up throwing parts at the car to no end.

[Ethenski]

Can see both cam gears + some timing chain by taking off the upper timing cover. If you know what to look for you can probably tell if it's been replaced. If you want to see all the guides and tensioners you'll have to take off the front bumper and radiator, then the lower timing cover needs to be replaced once opened up. Best method is to look through service records lol. I think the tensioner is the real problem on these cars, not timing chain correct me if I'm wrong.

Also AFAIK that vibration is a mystery problem that some of these have. If getting your wheels balanced doesn't fix it you may end up throwing parts at the car to no end.

I looked at the thread Theiceman linked, is there some way to check the tensioner through OBD? (I'm not too mechanic savvy)

Do you think I should just not even bother taking the car apart to check, and just get a quote from the dealer to see how much they can replace it all for? Wish I knew about this problem before I bought the car, seems like a big hassle, but also a time bomb if I don't look into it.

[smang]

I don't think you can scan for the tensioner because it is not electronic but not positive... took me a 3 day weekend to take the front end off and put it back on, really not too difficult and I didn't know shit about cars 6 months ago. If you plan on driving the car forever you'll want to be sure the tensioner was changed. May be helpful to contact previous owner and ask if you can't find it in the service records or dealer info.

[Theiceman]

Correct you can not check electronically. But its literally a 10 minute check on ramps. There is an inspection port you pop.off and you can snap a pic.
Google humble mechanic audi chain tensioner"

Sent from my SM-G973W using Audizine mobile app

[J.kaseno]

I seen online, as well as reading in threads, that you can view cam phase adaptation value, I believe that's what it is, to understand how your timing chain is. Can't remember if this was regarding chain stretch?

[Smac770]

The adaptation value gives you a feel for the extent of the chain stretch. It's not authoritative like visually checking the tensioner extension, but it's a hell of a lot more convenient for just wanting a "should I care to check yet".

But it says nothing about whether you have the defective tensioner or the corrected tensioner.

[J.kaseno]

The adaptation value gives you a feel for the extent of the chain stretch. It's not authoritative like visually checking the tensioner extension, but it's a hell of a lot more convenient for just wanting a "should I care to check yet".

But it says nothing about whether you have the defective tensioner or the corrected tensioner.

That's right, I remember checking that now and remember thinking I'm good...for now. Of course it won't tell you which version tensioner you've got. Just wasn't sure how accurate that reading was to actual chain stretch

[morris39]

The adaptation value gives you a feel for the extent of the chain stretch. It's not authoritative like visually checking the tensioner extension, but it's a hell of a lot more convenient for just wanting a "should I care to check yet".

But it says nothing about whether you have the defective tensioner or the corrected tensioner.

Yes to all your points. But I am trying a different tack as an early warning of chain/tensioner problems on a car that is definitely not broken (2.0 TFSI MQB). VCDS provides camshaft adaptation values for both cams and in my case it is 0 Deg for intake and 3.7 deg exhaust. But there is also an adaptation value to use after cam chain replacement which I take as the same as the original factory value. If I adjust the adaptation for the chain replacement number I get is 0.5 deg.
I notice that this effect seems to be common on the not broken VAG cars posted in the Ross-Tech site. One suggestion is is that this phase shift is emission related. My measurement is at idle so may change under load. So far for 2000 mi there has been no change.
I see you often post on Ross-Tech. Opinion? I have asked about this on different forums with 0 responses, Obviously of questionable use on high mileage engines.

[Smac770]

Yes to all your points. But I am trying a different tack as an early warning of chain/tensioner problems on a car that is definitely not broken (2.0 TFSI MQB). VCDS provides camshaft adaptation values for both cams and in my case it is 0 Deg for intake and 3.7 deg exhaust. But there is also an adaptation value to use after cam chain replacement which I take as the same as the original factory value. If I adjust the adaptation for the chain replacement number I get is 0.5 deg.
I notice that this effect seems to be common on the not broken VAG cars posted in the Ross-Tech site. One suggestion is is that this phase shift is emission related. My measurement is at idle so may change under load. So far for 2000 mi there has been no change.
I see you often post on Ross-Tech. Opinion? I have asked about this on different forums with 0 responses, Obviously of questionable use on high mileage engines.

You're asking about the Gen3 engine, which has dual VVT and therefore who knows how the values relate. The NAR B8 never used the Gen3, ROW did for B8.5. As such, I know nothing about hands on with a Gen3; I don't have one. The B9 uses the Gen3B, which for NAR is pretty much the same as the Gen3A in the ROW B8.5. So you might find more knowledge of the VVT values on the Gen3 in the B9 forum. The lower power B-cycle Gen3B used in ROW is a very different animal.

The VVT is certainly emissions related, it's how the engine implements internal EGR so it doesn't need any external EGR hardware. Among other things. But this extra measuring value you refer to, it would seem to have no parallel on the Gen2. So I don't have anything helpful for you, sorry.

[Theiceman]

Yes to all your points. But I am trying a different tack as an early warning of chain/tensioner problems on a car that is definitely not broken (2.0 TFSI MQB). VCDS provides camshaft adaptation values for both cams and in my case it is 0 Deg for intake and 3.7 deg exhaust. But there is also an adaptation value to use after cam chain replacement which I take as the same as the original factory value. If I adjust the adaptation for the chain replacement number I get is 0.5 deg.
I notice that this effect seems to be common on the not broken VAG cars posted in the Ross-Tech site. One suggestion is is that this phase shift is emission related. My measurement is at idle so may change under load. So far for 2000 mi there has been no change.
I see you often post on Ross-Tech. Opinion? I have asked about this on different forums with 0 responses, Obviously of questionable use on high mileage engines.

bottom line is you are comparing apples and oranges if you are comparing to cars on this forum. You need known good and lots of data to see if any of the numbers change as the chain wears and what those numbers look like. This is how we established our numbers and the limits.
Starting something on the b9 forum may be a great start.

[morris39]

@ Iceman & Smac770
Thanks for taking time for detail responses, good stuff to know. I did not post on A4 B9 forum b/c there is very little discussion of that kind and when I had asked a simpler VCDS question there were no replies.
I enjoy your forum. Too bad you are having all those troubles but it makes for interesting reading.

[RPMtech147]

I think the tensioner is the real problem on these cars, not timing chain correct me if I'm wrong.

When I see the tensioners fail it seems more times than not they're wasted because the chain stretch was so bad.... but the tensioners do fail.

To answers OP's question: On these engine, your safe bet is to treat the chains just like a timing belt. If it hasn't been done by 100,000 miles you're driving on borrowed time. If you have no record of them being done then you should do everything in your power to do them. When you lose a chain the valve job triples or more the cost of doing a quick chain/tensioner swap.

[Smac770]

@ Iceman & Smac770
Thanks for taking time for detail responses, good stuff to know. I did not post on A4 B9 forum b/c there is very little discussion of that kind and when I had asked a simpler VCDS question there were no replies.
I enjoy your forum. Too bad you are having all those troubles but it makes for interesting reading.

I imagine that'll be the case until the cars are old enough that people start working on them on their own (vs. in-warranty times). It's also a bit impossible to work out parts while the ETKA clones sites have no B9 data. parts.audiusa.com is a complete joke when it comes to parts diagrams.