Heavy clunk noise

DaPol · 9th April 2017, 19:26

I've got a bit of an odd one.

I'm getting an occasional heavy "Clunk" noise, as if something's hitting the underside - sometimes when I start the car, sometimes when moving off, but there's nothing I can reliably do to cause it to happen.

The car's a CDTI, and so far I've checked the lower engine mount (fine), the rear control arm bush on the offside (fine, once I'd fixed the ballsup that a cheap never-to-be-used-again mechanic had caused when fitting the new bush - bolts spinnable with a stubby spanner at arms reach - since nipped all the way up), checked the center balljoint on the (new) control arm which is fine, just replaced almost everything on the top half of the suspension on that side (new spring, shock, bearing, rubber flange, mount...), checked all of the pinch bolts for torque and they're fine, and can't seem to get the droplink to cause a rattle.

The engine isn't causing the rattle that I've heard recordings off that might point to a dead crankshaft pulley, but the car does have about 190k on the clock.

So, given that I *appear* to have ruled out the suspension and lower engine mount, and can't get it to reliably happen - does anybody have an idea what might be causing a heavy clonk noise that *sounds* like a dead lower engine mount, but from the right hand side?

Walter · 9th April 2017, 19:51

Quote:

Originally Posted by DaPol

I've got a bit of an odd one.

I'm getting an occasional heavy "Clunk" noise, as if something's hitting the underside - sometimes when I start the car, sometimes when moving off, but there's nothing I can reliably do to cause it to happen.

The car's a CDTI, and so far I've checked the lower engine mount (fine), the rear control arm bush on the offside (fine, once I'd fixed the ballsup that a cheap never-to-be-used-again mechanic had caused when fitting the new bush - bolts spinnable with a stubby spanner at arms reach - since nipped all the way up), checked the center balljoint on the (new) control arm which is fine, just replaced almost everything on the top half of the suspension on that side (new spring, shock, bearing, rubber flange, mount...), checked all of the pinch bolts for torque and they're fine, and can't seem to get the droplink to cause a rattle.

The engine isn't causing the rattle that I've heard recordings off that might point to a dead crankshaft pulley, but the car does have about 190k on the clock.

So, given that I *appear* to have ruled out the suspension and lower engine mount, and can't get it to reliably happen - does anybody have an idea what might be causing a heavy clonk noise that *sounds* like a dead lower engine mount, but from the right hand side?

could it be a loose exhaust hitting body

Steve1966 · 10th April 2017, 08:25

I second the exhaust. It's probably hitting one of the cross braces due to sagging rubbers. I put a cable tie around each one of mine (around the perimeter of the rubber to stop it being able to stretch as much). 2 years later and still no clunks. You might be able to shake the exhaust up and down by holding the tailpipe enough to make the clunk as a secondary check.

stevestrat · 10th April 2017, 09:03

Quote:

Originally Posted by Steve1966

I second the exhaust.

Had that myself, the exhaust dropped just enough to bring it into occasional contact with the tunnel crossbraces, it was a really solid clunk when it did. Try replacing the mounting rubbers/bending the mounts on the pipe. My mechanic mate actually ended up manufacturing an additional mount at the rear of the straight section before it bends to the silencer.

DaPol · 30th April 2017, 15:32

Well, finally got an uninterrupted day with decent weather to get the car wheels up.

Prodding and wobbling things shows that the OSF wheel has a bit of free play left to right, and staring at all the bits it could be it looks like the free play is on the joint between the tie rod and the steering rack, so I'm making an educated guess that the inner tie rod ball joint has worn and the clunking I'm getting is that whacking back and forth.

So, I get a merry day some weekend soon taking my steering to bits

Thankfully DMGRS are showing stock of replacement inner tie rods, so bit of luck there.

David Lawrence · 30th April 2017, 15:48

Quote:

Originally Posted by DaPol

Well, finally got an uninterrupted day with decent weather to get the car wheels up.

Prodding and wobbling things shows that the OSF wheel has a bit of free play left to right, and staring at all the bits it could be it looks like the free play is on the joint between the tie rod and the steering rack, so I'm making an educated guess that the inner tie rod ball joint has worn and the clunking I'm getting is that whacking back and forth.

So, I get a merry day some weekend soon taking my steering to bits

Thankfully DMGRS are showing stock of replacement inner tie rods, so bit of luck there.

Let us know how you get on as i have a set waiting to go on one of mine. The other car seemed to be making the same noises but a bit of prodding today reveals that the front drivers side drop link is worn. It was purchased supposing to be a genuine delphi only about 2 years ago. For a while its knock didnt reveal itself with normal inspection, but this weekend it started to get steadily worse and when i checked again it was not only worn, but also its top stud has become loose.

At least it is an easy job. Just wish finding genuine decent parts was as easy. Ecp are showing Lemforder links for £22 each after the discount and DMGRS is showing something called OEM-Q at £14.99

https://www.dmgrs.co.uk/collections/...inks-rbm100240

http://www.eurocarparts.com/ecp/c/Ro...f10ef19&000016

I thought i made a good choice buying delphi, but the doubt is now that they probably were not genuine. This is a bit of a worry since i fully refurbed both cars front and back with all new delphi 2 years ago. Reckon i will need to go round them all and check them carefully.

DaPol · 30th April 2017, 15:55

OEM-Q on DMGRS is "Original Equipment Manufacturer Quality" I believe - basically "As good as Rover would have installed"

Will update when I've done this - I'm out of the country for the rest of the week, so it'll be next weekend at earliest, but I don't really expect the parts to arrive much before that.

9th April 2017, 19:26	#1
DaPol Loves to post 75 CDTi Saloon Join Date: Jun 2010 Location: Bolton Posts: 302 Thanks: 47 Thanked 77 Times in 49 Posts	Heavy clunk noise I've got a bit of an odd one. I'm getting an occasional heavy "Clunk" noise, as if something's hitting the underside - sometimes when I start the car, sometimes when moving off, but there's nothing I can reliably do to cause it to happen. The car's a CDTI, and so far I've checked the lower engine mount (fine), the rear control arm bush on the offside (fine, once I'd fixed the ballsup that a cheap never-to-be-used-again mechanic had caused when fitting the new bush - bolts spinnable with a stubby spanner at arms reach - since nipped all the way up), checked the center balljoint on the (new) control arm which is fine, just replaced almost everything on the top half of the suspension on that side (new spring, shock, bearing, rubber flange, mount...), checked all of the pinch bolts for torque and they're fine, and can't seem to get the droplink to cause a rattle. The engine isn't causing the rattle that I've heard recordings off that might point to a dead crankshaft pulley, but the car does have about 190k on the clock. So, given that I appear to have ruled out the suspension and lower engine mount, and can't get it to reliably happen - does anybody have an idea what might be causing a heavy clonk noise that sounds like a dead lower engine mount, but from the right hand side?

10th April 2017, 08:25	#3
Steve1966 Loves to post 2000 W Rover 75 Saloon 1.8 Man Club (SE) Join Date: Mar 2012 Location: Warwickshire Posts: 436 Thanks: 66 Thanked 95 Times in 48 Posts	I second the exhaust. It's probably hitting one of the cross braces due to sagging rubbers. I put a cable tie around each one of mine (around the perimeter of the rubber to stop it being able to stretch as much). 2 years later and still no clunks. You might be able to shake the exhaust up and down by holding the tailpipe enough to make the clunk as a secondary check. __________________ Jobs Done since (Apr 2012): Spyhole, Thermostat, IMG (x2), Front ARB Drop links (x3 pairs), Rear Damper, Coils/HT Leads, Heater Matrix, Unions, 13x tyres, Gearbox Oil, Full Service (x3), Water pump & belts, LH/RH lower arm & bushes, Front/Rear pads/Discs, Fr door finishers, Track Rods, Jule's intake tube, Clutch, Slave, DMF (ouch), 1 1/2 exhausts, front springs/top mounts, Jule's Fan upgrade/condenser, reverse gear switch, OSR upper arm, spring, and sill welding. 78,000miles (175,600m total).

30th April 2017, 15:32	#5
DaPol Loves to post 75 CDTi Saloon Join Date: Jun 2010 Location: Bolton Posts: 302 Thanks: 47 Thanked 77 Times in 49 Posts	Well, finally got an uninterrupted day with decent weather to get the car wheels up. Prodding and wobbling things shows that the OSF wheel has a bit of free play left to right, and staring at all the bits it could be it looks like the free play is on the joint between the tie rod and the steering rack, so I'm making an educated guess that the inner tie rod ball joint has worn and the clunking I'm getting is that whacking back and forth. So, I get a merry day some weekend soon taking my steering to bits Thankfully DMGRS are showing stock of replacement inner tie rods, so bit of luck there.

30th April 2017, 15:55	#7
DaPol Loves to post 75 CDTi Saloon Join Date: Jun 2010 Location: Bolton Posts: 302 Thanks: 47 Thanked 77 Times in 49 Posts	OEM-Q on DMGRS is "Original Equipment Manufacturer Quality" I believe - basically "As good as Rover would have installed" Will update when I've done this - I'm out of the country for the rest of the week, so it'll be next weekend at earliest, but I don't really expect the parts to arrive much before that.