Expensive Noises?

[peterc]

I am becoming increasingly concerned by a whining noise that can be heard at high speed from my 1991 S3 (48k miles). The noise suddenly appears at a little over 70 mph and gains in intensity as speed is increased. The noise is directly related to road speed NOT engine revs.

The noise was not present prior to fitting four new tyres, but I do not believe this to be relevant, just a coincidence. Unless someone knows diffferent?

It is very difficult to identify exactly where the noise is coming from, somewhere below the gearshift is my best guess.

I intend to get under the car very soon and check gearbox & diff oil levels and to look for any signs of a problem.

Does anyone have any ideas or advice? Ever had a similar problem and know the fault/solution?

Any help much appreciated.

[lavingp]

You would be surprised how much road noise varies with different tyres. I had a very worrying noise from my Ford Probe that disappeared when I changed tyres.
Does the noise change when changing road surface (e.g. from old to new tarmac) and what brand of tyres did you have before and after changing?
Paul.

[Paceracing]

Hmmm, i'd check the oil level in the gearbox first and if that isn't the problem you could have a gearbox bearing on the way out. Not exactly bundles of money as it's just a Ford Sierra 2.8i gearbox, but it's a pain in the arse none-the-less.

Jas.

[peterc]

Unfortunately I do not believe that the problem is road noise from new tyres.

I am an engineer by background and previously worked for a bearing manufacturer - the noise sounds a lot like a bearing or bearing cage failure to me, but I was hoping it was something else.

The problem is, if I have to remove the gearbox to repair/replace then there are lots of other things that you would ideally need to address at the same time. The costs would include:

Gearbox replacement
New clutch plate, pressure plate etc.
Reconditioning of engine (whilst you have access)
New oil pump?
S/S Manifolds & exhaust?
All gaskets and bits & pieces

I could perhaps do most of the work myself, but would prefer have the car serviced professionally. The big question will be who can I trust to do the work? Anybody got any recommendations on suitable companies in the Northants/Leicestershire/Warwickshire area?

[dern]

I went through a similar process last year when I lost synchromesh in 4th. I decided to take out the engine/gearbox myself (hadn't done it before) and get the gearbox reconditioned. Rough estimates of getting a dealer to do all the work was incredibly expensive £1500+) but it didn't turn out to be too difficult (mostly). I bought a crane for 200, the new clutch was just over 100 and the gearbox reconditioning was only 200 (new synchro, bearings & seals). I didn't bother replacing the exhaust although it needs doing now. I would probably change the manifolds with the engine in place anyway as having them attached to the engine made it more difficult to get in and out of the car.

Hope this helps,

Mark