Subframe bushes

[boombastik]

Hi all,

Has anyone had front subframe bushes fail on there b7 RS4 before.

My car has had an intermittent fault since I got it 3 months ago. I've found this cracking metal to metal noise after long periods of driving when I have stopped to park, for example if I pull up and hard lock right then select reverse and start moving backwards there is a loud cracking noise as the car starts to move once moved the noise stops unless I select first gear and move forward you can feel it transferring thru the cars floor and feel it in your feet.

It's been back to the dealer I purchased it and they were unable to find anything on the last 3 visits.

Today a short 15min journey and the noise started again took it to the dealer and on the ramp. Can't see anything then I noticed the passenger side front subframe bolt looks like it's been moving as you can clearly see the mark where the washer should be sitting. Mechanic put a bar on it but it's solid. Because this is right below the exhaust manifold I'm thinking heat transfer is causing the bush to fail, when the car is cold you can't hear a thing.
Looking further beyond the bolt you can see an unpainted part of the chassis that the subframe would usually cover.

Has anyone had these bushes fail due to heat transfer from the exhaust manifold. Dealer is presuming 2 days to replace and is going to speak to audi and get some repair times

So looking to see if this is a known problem

Cheers in advance guys.

[coffey555]

I had exactly the same thing the other week. Turned out to be a dry bush on the subframe, my man gave it a good coating of lube to fix it.

It only did it after about 15 mins of driving so guess it must have been heat soak from the engine related.

Might have to change the bushes for the long term but it will do for now.

[boombastik]

Lubricting the bush won't last that long with the amount of heat transferring from the exhaust.

Looking at the underside it looks like a large job dropping the subframe.

[coffey555]

Probably not but hopefully it can wait until the next fault developes or I get round to gutting the pre-cats.

[tom2009uk]

Have they tried tightening the subframe bolts, had the same problem and this was the fix for me. Tom

[boombastik]

Yeah the mechanic put a breaker bar on it and it was solid

[Surrey Sam]

Have you checked your steering rack as the bolts on that can come loose.

[boombastik]

If it was the steering rack I'm sure the noise would be there all the time but it only happens once the car is up to temp

[coffey555]

I have a slightly noisy steering rack and the subframe noise is much louder. I actually thought I had a cv joint on its way out it was that loud.

Worth lubing the bush to see if the noise goes away and then replace as needed.