Knocking noise - road speed related
 

Fix one problem and another appears.....

One the 'new' V70, it's just started developing a knocking noise that's road speed related and only audible below 40ish mph. Clutch in/out makes no difference.

I've checked the hub bolts, both are tight.

Can't seem to replicate it in the drive on axle stands. I've noticed there is more lateral movement in the offside drive shaft than on the car I'm selling, could this be a clue?

Any suggestions on next port of call? Could a CV joint knock under normal driving, rather than on tight turns?

Assume that after fixing the engine problems, it's now developing power/torque as it should and has stressed something on the transmission.

Car is an '03 V70 D5 (manual) with 202k on it.

Hi,

Two things I would check;

First check for a stone or nail in the tyre.
Next the ABS wheel sensor might be just clipping the toothed ring on the drive shaft.

Good luck.
bob

Might sound silly but I had that problem before and there was a stone stuck in the tyre thread.

If no stone is found....check your drop link....

and it's now refusing to do it, although only been round the block today. Hoping it was something silly that has cleared itself - time will tell.

Have noticed a slight knock (unrelated) coming on/off throttle, guessing a mount or 3 will be in need of inspecting.

Was a definite and heavy knock that you could almost feel on the car floor - Hmm, scratches head!

Hmm these old v70's seem to be prone to phantom knocks--been having rear knocks off and on for 2 years on mine and never been able to find it--quiet at the mo but perhaps tempting fate.

HAHA - sounds familiar, been hunting a suspension knock for ages at the back of the old V70 (the one I'm selling), finally found it - the exhaust heat shield had a broken fastening and was knocking on the back box on bumpy roads - which is all the roads round here! May be worth checking on yours

Just a bit of an update;

Found a bit of time to get under the car and have a good inspect of everything. All the ball joints seem good from the best I can lever things with a big screwdriver. Founf that there is quite a lot of lash in the driver side (RHD) driveshaft and I can definitely hear a metal on metal clunk from the outer CV joint at certain positions.
Have ordered a new (used) driveshaft to see what that does to alleviate the issue.

I'm a little bit thinking engine (or due to the engine mounts). Hopefully not some knocking due to a loose cam belt or a problem with the pulleys on the serpentine belt. Maybe give these a check (if the cam belt was replaced by someone else, I'd make sure he used quality parts)

It’s road speed, not engine speed related. Can dip the clutch and the noise continues at the same frequency. The only play I can find is in the driveshaft. Time will tell I guess.