Knocking noise on acceleration

[maggotcorps]

Driving home the other day all was well, apart from the massive key marks all over my bonnet courtesy of some chavy c**t!!!!! Then i started hearing a knocking noise coming from my car, i slowed down to have a listen and it went. The noise only happens when i put my foot on the accelerator and it speeds up with acceleration, sounds like its coming from the rear drivers side. I've been under the car and had a quick look, couldn't see anything obvious. Any ideas what this could be?

 

[zcacogp]

At a (very) wild guess, possibly a CV joint?


Oli.

 

[Fen]

I agree with Oli's first guesstimate.

 

[zcacogp]

Ha! I'm a genius! I have never seen the CV joint on a 944, and haven't the foggiest what happens when they go west, but I managed to come up with a sensible suggestion given a sketchy set of symptoms and a car which I have never set eyes upon!

Handsome AND a genius - what more can you want! []


Oli.

 

[maggotcorps]

Thank you, you beautiful genius. I'll have a look. How can you tell if a cv joint has screwed up?

 

[zcacogp]

It makes a knocking noise on acceleration, increasing with road speed ....

No, seriously, I don't know. On a FWD car, you can diagnose it more accurately by increasing the steering angle, thus the slip angle on the joint by driving 'round in a tight circle. On a RWD car, this isn't an option.

Try jacking the car up and giving it a good wiggle? Can't be sure tho'.

The only 100% garunteed method is to change it, as far as I know, but others may be more helpful.

The next question is 'inside or outside CV joint?' And I don't know the answer.


Oli.

ETA: You may find that one of them has worn out because the rubber boot is torn or loose, and hence all the grease has been lost. This is a dead give-away. (Don't be tempted to just change the boot, and do it on the cheap. Always bite the bullet and change the whole joint.)

 

[Guest]

Takes me back to my Fiat X1/9 days....

If you can, peel back the wheel end of the rubber boot over the CV joint and look for bits of broken metal. Dead giveaway.

 

[maggotcorps]

dam this forum is awesome. cheers fella's i'll have a look after work.

 

[333pg333]

A knocking noise under load can also mean something way more serious. Possibly engine bearings. I would have that checked out asap. Mine came to a complete halt yesterday after hearing knocking sounds so be carefull.

 

[Guest]

Hi , My 944 has just started doing the same thing , it did it for a short time about a month ago then it stopped , and it just started again yesterday . A clicking/knocking sound coming from the rear , but only when accelerating. A problem with the CV joint was my first thought as well , have you discovered if this was the problem yet ?
Thanks
James

 

[pse_SC]

Definitely sound like a CV making the noise. Had it on my 924 Turbo. Unless it really is noisy and they are broken up, try this:

Swap the driveshafts over (side to side). It stopped the noise on mine. When swapped they're rotating in the opposite direction to the way they have previously worn - makes sense?

Obviously worth cleaning & re-packing the boots as well.

 

[Guest]

Aaaah...just posted same query on Titanic as SCZ has started doing exactly this. Will go to doctors later, how many labour hours to fix? I guess parts are the least of the cost...

 

[macandsue]

If you are not too fussy about second hand parts try Douglas Valley breakers advert in P.P etc you get the whole driveshaft cheap,by return.Mine was as tight as a new one.They are not cleaned up to look new.6000 miles later still going well .IF you are really keen you can then re con your old one at leisure then when number 2 goes you have the spare ready.1 or two hours to change single handed easy, 10 or 8 mm hex drive needed .