Engine Mounts Leaking 15 A8 4.0
 

I recently had my independent Audi shop give my car a look over and among the recommendations was to replace leaking engine mounts. Estimate is $3,000. Assuming that parts are ~450-470 x2 that comes to almost 2k in labor. They said it's pretty hard to get at for the swap out.

Has anyone here had this done? Are they way off base WRT labor?

Looking at the procedure for a 13 A8 it is a very in depth process. Lots of little things that need removed or disconnected, then all of it put back together.
EDIT: The left side mount is the "trouble child", right side mount is much less involved. Oddly, it specifies to use a jack when removing left side, and a crane type support when removing the right.

I would say that labor estimate is appropriate.

Are there any symptoms besides them saying it's leaking? Vibrations? Noises?

As the first reply sort of indirectly implied, FWIW back to OP my reaction is not enough info. so far. Please specify which mounts exactly, or get more info from the mechanic.

There are probably three mounts on the D4 4.0T. The two everyone thinks of left and right, but then also the car probably has a torque mount. On D3's that is the hardest one to change even though it is not under weight load when the car is off. On both my C5 4.2 and my D3 W12, it was the (only) one that failed out to 150K+ miles. Many hours with either of those. You can literally see it from above, but is in a gawd awful place jammed in by the water cooled alternator. The main ones require engine support to come out. And yes, IIRC the left/USA driver's side one the other reply mentioned got a lot harder when they went to the chain drive motors with FSI. A lot of the auxiliary items are then driven by a splined shaft drive (instead of belt) and those are concentrated on that left side, at least they were on late D3's.

Thanks for the feedback. I'll need to circle back with the mechanic. Quote only specifies two replacement mounts so I can only assume the two motor L and R at this point until I get more info.

Your note about mileage got me thinking, how could these fail so soon? I just recently picked this car up used at 69k. I know it has the 1k/3k vibration issue. Do you think that could be the sole source of my leaking mounts?

Bottom line, getting on it repeatedly over the miles with a high torque motor is probably the prime enemy and factor in mount failure. Any tunes put to serious use would probably stress them further. Hence in retrospect my D3 W12 w lots of torque blew a torque mount by about 65K miles, and apparently has blown it again at about 140K (car remains in extended family). Also, when a mount fails, if not attended to the other one(s) get further stressed. Hence, important to attend to promptly.

On flex joints/exhaust head pipes, if anything I would expect issues with them would more likely be a byproduct of failed engine mount issues, rather than the other way around. That is, failed mounts can allow more overall movement, which would further stress the exhaust flex joints.

Just had the two (L+R) engine mounts replaced. Torque/trans mount was okay. Definitely smoother but still a small vibration if you look for it revving in park/neutral. Next step will be finding an exhaust shop willing to determine the precise length needed for an A8 L flex pipe replacement and update the stock pipes. Will report back results when that happens.

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How did all this play out? Did you install SS flex joints? Did you move this to another thread?
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Apologies for the late response. I was out of town for a road rally!

I ended up sourcing the OEM downpipes and had them installed by my local Audi indy. Worked like a charm!

I think replacing the engine mounts was good maintenance but had no real impact on the vibration.

Going the full replacement route on the downpipes was expensive but in the end was the solution to the problem. I don't doubt that finding a competent muffler shop to do a custom flex pipe install would also fix the problem.

Response gap from 2/20/2018 to 3/29/2021 made me wonder... was it a 'round the world rally?

Ha! That would be epic. However was just referring to @A8L_New_England 's post on the 26th.

In reality it was a ride through southern Missouri with the S2000 Boston Mountains Tour group. They typically hold these in Arkansas but decided to change it up. While the group is primarily Honda S2000 enthusiasts there are all types of cars in their events.