Knocking Noise - Please Help!

[stedolan]

Hi Guys

Yet another problem with the old beast Got in the car this morning and after 5 minutes of driving a knocking noise started beneath the car. It's quite a loud 'clunk clunk' sound and only occurs while the car is moving (whether the clutch is engaged or not). Anyone got any ideas?

Thanks, Ste

[jameswkr]

How often does the "klunk" noise happen? - is it speed related? - ie per wheel revolution. Did you drive over something that is now stuck to the car ? Have you looked underneath ??

[alg]

^ yep you should always check for bodies under the car when it clunks. Assuming there are none. Think topmounts, balljoints & dampers.

[Graham]

Prop shaft center bearing?

[Jas11n]

Couple of things I've had in the past that have caused clunking.

1/ Borked engine mounts causing the sump to hit on subframe at the front. Due to a crap mechanic at a crap garage who couldn't be arsed to fit them properly, but someone replied in my thread at the time saying his engine mount was worn enough to do this too.

2/ Wheel bolts had come loose on rear nearside wheel. My fault for not torquing to correct spec. This caused the mother of all clunks. (note, it took 5 months for them to come loose)

[stedolan]

Thanks guys for the replies!

There are two 'klunking' noises per wheel revolution and it gets faster and quieter as I speed up! I've had a quick look underneath, but I couldn't see anything obvious. I'll jack it up later and have a good look around. What's the worst case scenario and how much is it likely to cost?

While I'm on here I might as well ask a few more questions:

- I need new discs and pads for the front brakes, what brand should I be looking for and where am I best going? May need a hand brake cable also.

- What's the best way to wind back the rear calipers, can I just lever them back?

- The black border around the windscreen is starting to discolour (looks a bit like spilt rice pudding!). This happened on my last Coupe as well, is it normal? Can anything be done?

Cheers, Ste

[Graham]

Thanks guys for the replies!

There are two 'klunking' noises per wheel revolution and it gets faster and quieter as I speed up! I've had a quick look underneath, but I couldn't see anything obvious. I'll jack it up later and have a good look around. What's the worst case scenario and how much is it likely to cost?

- What's the best way to wind back the rear calipers, can I just lever them back?

- The black border around the windscreen is starting to discolour (looks a bit like spilt rice pudding!). This happened on my last Coupe as well, is it normal? Can anything be done?

Cheers, Ste

The klunking noises could be the items listed above, 2 per rev could indicate something on the hub as the prop shaft spins about 4 times per rev so shouldnt be that.
Definitely check the wheel nuts asap, as other than being a really cheap fix for a serious problem, could save your life aswell.
Other than that, CV joint?--although unlikely as they are fairly bullet proof, or sticky callipers causing the pads to clunk, or wheel bearings.
To check wheel bearings, cv joint, or brakes, Chock the front wheels, with hand brake off and in neutral, jack it up and grab the wheel at 3 o'clock and 9 o'clock and wobble vigourously, play indicates possible wheel bearing, (can also indicate worn mounts and tie rods), spin the wheel see if the brake catches, or the CV joint clunks. I wouldnt advise doing the 12 o'clock, 6 o'clock test unless you use a trolley jack and NOT the supplied car jack, but if you do this wobble it tests the bottom ball joint and bearing aswell.
Another one i have had is the exhaust touching the driveshaft where it goes round the rear diff--this indicates the exhaust mounts which have a chain moulded in them for added strength have failed.

The windscreen discolouration is a common fault and is the glue which holds the window going off, there is no easy fix other than having the windscreen fitted, and if its a coupe is a ball ache of a job for an expert--8 hrs. A good way is to ensure you have windscreen cover and have an "accident" then your insurance does it. Its not generally essential as long as it is sealed, it just looks not nice.
The rear callipers have to be screwed in, any calliper wind back tool will generally do the job, the sykes pickavant one is good, thats what i use.
Repair costs---------How long is a piece of string, but depending on how you feel about DIY then its best to ask the other forum members about reccomended garages.
DIY is generally the go for most forum members, but some places out their will do you a good deal without open wallet surgery and the repair quality will be good. The worst case scenario is a pi$$ poor job which is worse than it being expensive.

[stedolan]

Thanks for all your advice guys, I'm going to have a good crack at it over the weekend!

Ste

[220bhp]

Wheel bearing on the front can make the consistent noise you describe