DiagnosisUnknown

Hello all, I am looking for advice from someone who has been through this situation. I recently ran a VCDS scan on my '05 A8 with 85K mi and this showed up:
Address 01: Engine Labels: 077-910-560-BFM.clb
Part No SW: 4E0 910 560 J HW: 4E0 907 560
Component: 4.2L V8/5V G 0010

1 Fault Found:
17983 - Right Engine Mount Solenoid Valve (N145)
P1575 - 001 - Short to Plus - Intermittent
Readiness: 0110 1101

Reading on various forums it sounds like the solution is to replace the motor mount. I would say that if I didn't see the error in VCDS that I would not know there was an issue. The error immediately returns if it is cleared. I can feel the car vibrating very slightly while idling. Otherwise there is no indicator that something might be awry with a motor mount. I keep the car in like new condition so I want to fix the issue. The question here is:
When replacing a motor mount is it better to do all of them or just the one that the computer is complaining about? I can think of a few reasons that one might want to replace all of them but I'm not sure how valid they are:

• When one goes the others are bound to follow
• The replacement might be less compressed than the other original parts causing an imbalance
• It's cheaper/easier to replace the others while one is being replaced (think water pump with timing belt)
• It's possible to get a discount if you buy them all at once rather than individually (have not seen this one BTW)

I see I can get a part that is OEM equivalent from China for about half what I can get the OEM part for. Is it worth the risk given the cost of labor?
Finally, would you consider this a dealer only type of fix given that the engine is in flux?

Aceler8

I've never changed a motor mount in the A8, but from other experiences, i'd change the one throwing the code with an OEM part. I say this because our 2006 has over 200k miles and i've never changed a mount or had vibration issues to even attempt it so you may get many miles out of the other mounts.

I've tried off brand parts on our A8 and they seem to be inferior. Only caveat is suspension control arms as i've had good luck with rockauto ones.

Guess i'm suggesting is to save the money from the other mounts and put the cash toward the OEM mount to be replaced. Good luck and let us know your solution.

QuattroDaniel

H-audi!
Similar experience here, but on an S8.

I would first have an authorized shop or dealer confirm the error / problem. If it is for certain the motor mount, yes I would replace them all with factory parts. For the S8 the entire engine had to be removed, so they also replaced timing chain guides, hard to reach O2 sensors, various 'wearable' items, and did a carbon cleaning. If the A8 doesn't need the engine pulled, then I agree with Aceler8, just fix what's broken.

FYI; Seemed to be WAY more involved than the average at-home mechanic could handle, but maybe the A8 is less complicated?

Aceler8

WOW...engine removal for mounts....This is just one reason i passed on a 2008 S8 and purchased a 2005 Jaguar XJR. The Jag is much easier to wrench on with less computer interference. It uses a supercharger good for 400hp with rear wheel drive so its super fun to drive.

dvs_dave

Unless it’s actually leaking fluid, you’re better off just leaving it alone. The official fix from Audi was simply to bypass the circuit with a resistor, and then the active mounts where deleted from the later models. That should tell you all you need to know.

I guess it was a nice idea, but in practice the juice wasn’t worth the squeeze.

Here’s TSB 10 08 04 that covers it.

Mine has been throwing this error for a few years now, but as I know it’s safe to ignore, that’s exactly what I do, with no I’ll effects.

DiagnosisUnknown

Thanks for all of your input. I'll take Dave's excellent advice!

nathanwind

I replaced my one side when I had things apart for the timing belt / Bufkin pipe / radiator replacement....but that was only because I didn't know about the resistor/bypass approach until *after* I was finished. Do as Dave says, bypass it and leave it if it's not leaking.

Mister Bally

Make sure the goop hasn't already leaked out like mine did. The rubber damper was completely separated from the aluminum mount. And note that the replacement OEM part no longer has a connector. Thus, the service bulletin resistor fix should be performed.