Rumble when turning left only on the overrun

Objective

Member
Hi to everyone,
I have an ongoing problem that may indicate a bigger problem which is my concern.

I'm looking to fettle a rumble that only happens when we are driving along at over (say)15kph and above, only when stearing around any left hand corner and only on the overrun, i.e. a trailing throttle.
That last bit is my cause for concern.
The rumble, a sort of vibration that could be imagined as a body rubbing against wheel, but isnt (we checked) and also depends on whether the car is beiing driven forward, coasting or retarded (overrun) by the engine Only on the overrun do we get the noise. Only then, something is happening to cause the noise. Has something flexed, or shifts or bends? Whatever it is, we can't replicate the noise when she's up on the hoist? Everything seems tight, no body parts snag the FLH wheel or brakes seem sound, so maybe the front body is flexing somehow and just allowing a panel to vibrate ??

Has anyone any idea, or even guesses of a source. Has anyone any idea of how we can hunt down the cause. Is this just something to put up with, or something to find and fix pronto?
All knowledge apprecated, any opinions welcome, random thoughts respnded to ...
Kung Hei Fat Choy as they say East of here ...
 
Hi Objective (not the database?)

So your Rover's problem is speed, direction, and engine status specific. All being necessary simulataneously in order to deliver the unwanted outcome.
Can you see any evidence of contact when your wheels are turned to the left?
In what condition are your engine mounts? Are they oil damaged or not?

Ron.
 
It could be wheel bearings giving up the ghost, but the fact it’s happening under throttle lift I’d first look at engine mounts. Also, look at diff mounts. I found recently that the diff can move and make more noise on left hand turns, but in my case it was a bad differential.
 
I, too, would check the engine mounts. Try easing the engine up with a jack to make sure they are still attached (rubber to metal). Because they can settle or move about as they are loaded, and the exhaust manifold can contact the chassis rails, thus transmitting noise.
 
All,
The engine mounts ! Not something I considered so that'll be the first thing to check over. Easily get a jack under to lift, so I'll get to it. The exhaust could well account for the sound, being somewhat like a body part rattle.
Wheel bearings? Both front end wheelsrun without any rumble when off the ground, so I had discounted them ... but if I can put them under pressure via a side force (the turn) then I'll have another listen. How to do that .... errr.
The diff; certainly I focussed on the front, but I'll have a good snoop around the differential, make sure I haven't missed a duff mount.
Brilliant, and really appreciated.
Will report back in the next day or two.
Cheers
Paul
 
Just some thoughts - without preempting my investigations:
- are silicon mounts available for the P6 2000 ?
- a quick read and the FEBI BILSTEIN engine mounts seem to work (P6 2000TC 1971) is that true?
- I seem to have recall of Demitris saying the engine mounts can be replaced in-situ, I'll have a search for what I think was a very detailed post...
 
Silicon mounts aren’t available for the P6 to my knowledge

The Febi Bilstein mounts work well. You want the rear left transmission mount for a Mk.II Golf. I have them fitted to my car and they work well.

I believe you can just about do them in situ. But if you’re going to use the Golf mounts you may have to increase the hole size in the base unit by about 1mm, that hard to do with the engine mounts brackets in the way.
IMG_1255.jpeg
 
Try the car in reverse. Short hard acceleration in reverse. What you describe can be the front diff mount being loose. either the main through bolt or the rubber mounting bolts. If that's the case it will sound like the diffs about to part company with the car. aweful racket goes away when you ease off. It's the diffs front drive flange hitting its surroundings. happens on overun as the nose of the diff lifts on overun and in reverse.

Note that many of the rubber mounts are slotted and their orientation is important.
 
Now that is incredible knowledge ... Thanks Mike. shall try that ...

I first read that comment as the "front diff" and its mount, not the "front mount on the diff" - my brain exploded!
 
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