Right hand Motor mount fault code P1577

[C300]

1 Fault Found:
17985 - Right Engine Mount Solenoid Valve (N145)
P1577 - 004 - Open Circuit - Intermittent
Readiness: 0000 1000

did timing belt, ect. everything is great. cleared codes with Ross vag tool. this new code came up. so did I put a load on it when swinging front mount out of the way doing the timing belt ? causing it to fail ? torque front one too much?
is there some way to fix this or is it replacement time ?
If needs replacing. get this Genuine Audi Motor Mount 4B3-199-379-M ?
or get the 034Motorsport's Density Line Motor Mounts and Resistor Bypasses (https://store.034motorsport.com/resistor-bypass-active-motor-mount-b6-b7-audi-s4-v8.html).
or what's the best option. what has the forum suggested for this in the past. thanks !
I really want to tear it apart again :doh: <strike>
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[lswing]

Honestly don't know how much a slightly compressed or torn motor mount really makes a difference. Maybe a bit of extra vibration? I'd bypass it for now, and replace with your choice once you need to pull or move the engine again, shouldn't be too long:rolleyes:

Replaced two many years ago with OEM. It might just be the wiring or sensor causing the error to throw also as it's Intermittent.

[C300]

it shows as an engine fault. is this going to make it fail emissions ? this is my only worry. it didn't pass before. like every time. I was hoping to have no codes. get it to pass. if this is all it is i'll rip it apart again.

[lswing]

So does anyone know why the stock mounts use a solenoid anyhow? Do they actually lock up under load, and then unlock and remain softer when driving normal to allow less vibration?

[C300]

So does anyone know why the stock mounts use a solenoid anyhow? Do they actually lock up under load, and then unlock and remain softer when driving normal to allow less vibration?

I read it's so you realize the mount is compromised/damaged. They are hollow like most mounts, but filled with hydraulic fluid. This reduces vibrations. My opinion is that solid rubber ones would be better. Last a lifetime. Just don't know how it has worked for these RS6 cars

[hahnmgh63]

If you think the mount is good you can add a resistor to the the circuit to cancel the fault. Audi makes a resistor shrink wrapped with the proper plug. The part # is 4E0971067A
https://www.audiusaparts.com/oem-parts/audi-harness-4e0971067a $25

[hahnmgh63]

Here you go for even less.
https://www.rmeuropean.com/Products/0347080000-MFG979-V1436.aspx

[EINHORN]

Or even less from 034, 16 per and yes notwithstanding the lack of reference to the rs6 in the parts description, they fit and work, per discussion with them an hour ago