Strange noise!

[Roverdrive]

Hi

I could do with the virtual listening department having a think about this one please.

When starting from rest "briskly" there is a fairly loud noise coming from under the motor. It is a cross between a chirp and a squeek. Definitely metallic in timbre. It happens three or four times or beats, and then stops. Sometimes it will happen on the change between first and second.

The vehicle is a 300 tdi 110.

It only happens with high torque.

It will not do it in reverse.

Trying to pull against the hand brake does not provoke the noise.

Parts changed so far include all four ujs

All bushes on nearside hockey stuck

Drive flange.

A third party seemed to think it was coming from the nearside front of the vehicle.

There is minimal play in the front diff.

Driving in circles on full lock does not make any unusual noises from the cv joint, thigh that is the next thing I was thinking to look at.

Any other ideas?

Mike

[simonr]

What are your front trailing arm bushes like? I had a tinkling noise on deceleration which turned out to be one of the washers on the front trailing arms which only became loose on deceleration. Took months to find! While your noise is different with a different cause, it's where I'd look first!

Si

[Roverdrive]

Simon

Bit confused by fron t trailing arm, is this what I call the hockey stick?

Near side one do ne today and doing offside tomorrow.

Really hard to describe the noise, but I have heard similar when a uj was breaking up, hence changing all four.

[Tanuki]

Could it be the clutch? I've had a few vehicles whose clutches would squeak/yelp during fast takeoffs.

[Phil Wilson]

I'd put money on it being one (or both) of the U.J's on the front prop'.

[Roverdrive]

Tanuki, I did consider this, but I kind of clung on to the hope that it can't be the clutch if it doesn't happen on reverse! I would also expexpect some noise when slipping the clutch with the handbrake on??

Phil, I have changed all of the ujs since the noise appeared.

Mike

[Yostumpy]

Had something similar once on my old 110. I traced it to the fact that the front springs are different lengths, the DS one being the longer. When I lifted the clutch and took off, there was a similar noise, and I noticed the front NS would lift up maybe 1" on take off, and it was the shorter spring stretching and graunching on the spring seats. Once underway if didn't happen. So I lubed the spring seats/retainers and it stopped, but swopped for aftermarket springs of equal length.good luck in your quest. You could always remove front prop, and try it in difflock, that would eliminate any front prop, axle, cv, diff noises.

[Roverdrive]

Sorted!

It was an expensive day, but got the job done. Since the splines looked a bit worn, I decided to check the cv joint, and found a hair line crack in the cage. Changed it out and the noise was still there. Bu###r! In desperation I crawled back underneath to see if any stones had got jammed between the gear box and transmission tunnel, and spotted a stud missing from the NS engine mount. Fitted a new mount and the noise has gone. The strange thong is that there were no witness marks on the chassis to show a stud had been in there in the first place. When I took the nut from the DS mount to lift the engine slightly, there was bright ring where the nut had been

Go figure.

At least the noise has gone!

[Snagger]

Well done - not a cause I would have guessed at.

For what it's worth, Britpart CV joints are actually pretty good, according the Ashcroft Transmissions destructive testing. I've had good service from them, and they're one of the few BP parts I'd recommend. They cost me about £35 for the ABS equipped 300Tdi RRC.

[Roverdrive]

Looking on the bright side, if I had seen the missing bolt earlier I would not have checked the CV joint, and that would probably have let go when needed most. The bushes will see me through the next few years, so all worthwhile in the long run if not really needed just now!