Any A7 owners got their pinion and/or timing chain + tensioner changed?

[IbisA7TDI]

I was trying to have my rear wheel bearings inspected, so my warranty company sent out an inspector.

Instead, unexpectedly, the warranty inspector found 2 issues:

1. Pinion (part of the rear differential?) - never seen this as a problem with any other owners, but the shop tells me they put the car on the lift, and revved it a few times and inspector claimed it was the pinion rattling...

2. Rattle on startup (I previously didn't notice this, but hey, if he's claiming that he heard that I'm not denying that either because I know the 3.0 TDI engines have this problem area sooner or later), and approved to have the timing chain tensioner changed. I'm also paying a couple hundred out of pocket to have all the other parts that go along (rails, timing chain, guides) changed as well because why replace one only part if all the others have the same number of miles right?

These two things together are $5k worth of labor and parts that the warranty company covered.

If you were me, even if you didn't really notice these problems before, knowing that the timing chain tensioner is a part that is a problem area on the 3.0 TDIs, would you be comfortable changing out all these parts? My car is at 52k miles and drives smoothly... Though the shop is a local euro shop that is very reputable and works on exotics, Porsches, tons of Audis (and TDI engines too), I am still slightly worried I'm performing an "open heart surgery" on my car with things that I didn't notice were problems before...

[Burnt]

Hmm also have a 2014 audi a7 at 66k miles. Rattle on startup? I think I also have the same, I thought it was the same rattle all diesels have on startup

[Dutch_A6]

2012 A7 with 144k miles on the clock and dual pulley tuned. The rattle had always been there is a known fact with these engines, however it lasts only a second. Audi says that when it lasts longer than 3-5 second then the guides or chain stretch are issues. So at this point it's not a concern, I recently had the engine overhauled with thermostat, PCV & water pump and the tech said that other than a little oil from the rear upper covers everything looked good.

I might replace the tensioners when I did headers/down pipes and ported blower but for now it's still running like a champ.

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[AndreiMTM]

I have a TDI as well and currently at 85k, have had the rattle since I bought the car with 40k on it and who knows for how long before. It’s important to note that a lot of 3l TDI’s have the timing chain rattle, but there have yet to be any reported failures on the forums. It’s a really big job and since it doesn’t usually cause engine damage like on some 2l gasoline engines from Audi/vw, most people just let it be.

With that being said, if the shop is a reputable shop and You know they will do a good job on it, I would definitely have the work done under warranty. However if I had any suspicion that the car would have any issues afterwards from the repair not being completed correctly, since it’s an engine out job, I would just let it be.


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[Valpo A7]

I have the 3.0 TFSI and I just did the timing chains on my engine at 205k. It’s a motor out repair. Try to get the motor mounts done while they are at it since the mounts have to come out any ways.

[omegs]

I think the pinion they are referring to could be the driveshaft support carrier? I've seen some with a lot of flex under load.

https://www.youtube.com/watch?v=X1IRxKcoRMg

Silly Rabbit Motorsports makes and aftermarket one from what I remember. Not sure how bad yours could be with that kind of mileage.

[Valpo A7]

If they only put it on the lift and rev’d it and did not put it in gear and let the drivetrain turn then it’s near impossible to determine if the differential carrier bearings are making noise or if the drive shaft carrier loop is having problems.

[omegs]

Yo Vaplo A7, this might side tracking a bit, but do you have any advice that would you recommend while having the engine out? Like other thingss you could have replaced while you were in there? I only ask because I remembering looking at your timing chain DIY. I will be pulling the motor and doing a full rebuild at 126k. The current motor has a blown head gasket. Any other tips would be appreciated. I know for sure the timing guides are going to be replaced but do you think the chains should be changed out as well?

[Valpo A7]

Omega, if you are in that far you might as well do the chains as well. No need to spend the money on OEM chains, get the IWIS chains for a fraction of the price. The book calls for replacing a lot of bolts as you take stuff apart and go back together since they like to do torque to X Nm and then turn additional 90 or 180*. The trans bolts are aluminum and can be reused once more but be prepared to snap one. They are cheap from the dealer though. Changing the PCV would not be a bad idea along with water pump abs t-stat if you want to. I replaced my motor mounts as well since they were starting to fail.

Now just because the head gasket has popped does not mean that you must rebuild the engine. Now if you do decide to rebuild then it would be worth sending the heads to a machine shop to tear down and clean. They will grind valve seats if needed as well as mill the heads flat. You will want to check that the block is flat for head mounting surface as well. If not then you need to have the shop mill that flat as well. Take your time and get good measuring tools so you can check bearing clearances and all other things. It’s not a bolt it down and hope it’s right process.

Your gonna need a torque wrench that can get down to 5Nm and as high as 200Nm when everything goes back together. I already had a 3/8 and 1/2 drive torque wrench but they would not go low enough. I wound up buying a 1/4 drive torque wrench from Harbor Freight for about $25 to do the chains. Bought long and short triple square sockets, timing chain tool kit, flywheel hold devise, and a cv boot band crimping tool. My tool box was well stocked before so I already had the basic tools. Palm ratchets came in handy as well. I already had them and I also already had hose clamp pliers as well.

I am sure there’s more, feel free to send a PM

[IbisA7TDI]

Thanks everyone! I decided to go ahead and replace the tensioner, chain, guides, rails and all that with the shop. They do lots of engine out jobs, and especially the TDIs which was an important factor to me.

[AndreiMTM]

Thanks everyone! I decided to go ahead and replace the tensioner, chain, guides, rails and all that with the shop. They do lots of engine out jobs, and especially the TDIs which was an important factor to me.

Awesome! Let us know how it is afterwards.

If you don’t mind me asking, what’s the quoted price for the timing chain and guides service?


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[IbisA7TDI]

Awesome! Let us know how it is afterwards.

If you don’t mind me asking, what’s the quoted price for the timing chain and guides service?


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Labor and parts for the timing chain tensioner was $4k but that was covered by warranty company.

The rest of the guides, rails, timing chain, I just had to pay ~$700 for OEM parts, but labor was covered in that $4k.

[IbisA7TDI]

I have the 3.0 TFSI and I just did the timing chains on my engine at 205k. It’s a motor out repair. Try to get the motor mounts done while they are at it since the mounts have to come out any ways.

Thanks, yes! I had the both driver and passenger side motor mounts replaced under warranty last month as well :)

[IbisA7TDI]

Update:

Got my car back yesterday after it was in the shop for 2 weeks (couple of delays on parts shipments and tools needed).

The A7 is now smoother than ever!

Also went ahead while it was in the shop and flushed brake, coolant, transmission, and differential fluids (this one had to be done anyways cause of the pinion). Car is at 52k miles and I feel like it has an all-new life!