Knocking noise when cornering

timway · Oct 30th, 2007, 10:52

My S40 has just in the last few days developed an occasional loud knocking sound when going round roundabouts.... Its quite a regular sharp knocking, sounds a bit like a single cylinder motorbike with a loud exhaust. So far I've only heard it twice, both times on the same roundabout! (And I go through a lot of roundabouts on the way to work!)

I know there is a bit of wear in the rear trailing arm front bush, particularly on the LHS arm, but I'm not sure it could be the cause.

Sounds more like something could be rubbing somewhere under certain conditions... it had a new engine, clutch and turbo fitted last week, but I hope the noise isnt coming from there!

Any ideas?? I'm going to have a good look over lunchtime anyway for anything that looks loose/worn etc.

Boz · Oct 30th, 2007, 13:04

can you tell if it's from the front or rear?

If it's from the front, it could be a driveshaft CV joint. Notoriously more noticeable when cournering and roundabouts!
has your can done a lot of miles? It could be the CV joints are well worn anyway and being seriously disturbed when swapping the engine has finished them off.
Find a desereted car park and drive round (slowly) in tight circles to determine if its a front CV .

timway · Oct 30th, 2007, 13:43

The cars done 94,000. I'm not sure if the noise is coming from the front or rear, will try to listen more carefully next time. I haven't noticed any noises when turning slowly on full lock though. I jacked up each corner at lunchtime and tried to check the wheels for play etc, didn't seem to be anything wrong. I did notice a bad oil leak while I was under the car though

I think that maybe a turbo oil return pipe seal though and nothing to do with the noise. Anyway, looks like its back to the garage on saturday...

Johnt71 · Oct 30th, 2007, 21:10

I had an occasional noise from the rear when going over bumbs and cornering eventually on closer inspection it turned out to be a broken spring!
Only way I actually noticed it was jacking up the car and seeing the spring bowed. The noise was the spring rubbing on the damper.
Worth checking!

timway · Oct 31st, 2007, 19:39

Quote:

Originally Posted by Johnt71

I had an occasional noise from the rear when going over bumbs and cornering eventually on closer inspection it turned out to be a broken spring!
Only way I actually noticed it was jacking up the car and seeing the spring bowed. The noise was the spring rubbing on the damper.
Worth checking!

Thanks!, the rear springs look ok but I have traced the noise to the engine now anyway (unfortunately

) - the engine is making a sort of tapping hammering sound which only occurs under certain conditions (high rpm but light throttle), hence why it was only happening when cornering sometimes... maybe time to start a new thread

Oct 30th, 2007, 10:52	#1
timway Snail Wars: A new shell Last Online: May 17th, 2011 11:11 Join Date: Dec 2004 Location: bath	Knocking noise when cornering My S40 has just in the last few days developed an occasional loud knocking sound when going round roundabouts.... Its quite a regular sharp knocking, sounds a bit like a single cylinder motorbike with a loud exhaust. So far I've only heard it twice, both times on the same roundabout! (And I go through a lot of roundabouts on the way to work!) I know there is a bit of wear in the rear trailing arm front bush, particularly on the LHS arm, but I'm not sure it could be the cause. Sounds more like something could be rubbing somewhere under certain conditions... it had a new engine, clutch and turbo fitted last week, but I hope the noise isnt coming from there! Any ideas?? I'm going to have a good look over lunchtime anyway for anything that looks loose/worn etc. __________________ 2002 Met Blue S40 T4 Sport Lux, Jetex Exhaust, Race Cat, MTE Custom Remap, Bilstein B4 front shocks, SS Brakelines, EBC Redstuff pads, 17" Alloys, 14T-16G Hybrid Turbo

Oct 30th, 2007, 13:43	#3
timway Snail Wars: A new shell Last Online: May 17th, 2011 11:11 Join Date: Dec 2004 Location: bath	The cars done 94,000. I'm not sure if the noise is coming from the front or rear, will try to listen more carefully next time. I haven't noticed any noises when turning slowly on full lock though. I jacked up each corner at lunchtime and tried to check the wheels for play etc, didn't seem to be anything wrong. I did notice a bad oil leak while I was under the car though I think that maybe a turbo oil return pipe seal though and nothing to do with the noise. Anyway, looks like its back to the garage on saturday... __________________ 2002 Met Blue S40 T4 Sport Lux, Jetex Exhaust, Race Cat, MTE Custom Remap, Bilstein B4 front shocks, SS Brakelines, EBC Redstuff pads, 17" Alloys, 14T-16G Hybrid Turbo

Oct 30th, 2007, 13:04	#2
Boz Junior Member Last Online: Dec 15th, 2017 14:33 Join Date: Aug 2006 Location: Dagenham	can you tell if it's from the front or rear? If it's from the front, it could be a driveshaft CV joint. Notoriously more noticeable when cournering and roundabouts! has your can done a lot of miles? It could be the CV joints are well worn anyway and being seriously disturbed when swapping the engine has finished them off. Find a desereted car park and drive round (slowly) in tight circles to determine if its a front CV .

Oct 30th, 2007, 21:10	#4
Johnt71 New Member Last Online: Jun 7th, 2011 20:21 Join Date: Aug 2007 Location: Woking, Surrey	I had an occasional noise from the rear when going over bumbs and cornering eventually on closer inspection it turned out to be a broken spring! Only way I actually noticed it was jacking up the car and seeing the spring bowed. The noise was the spring rubbing on the damper. Worth checking!

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