Hello people

I have had a rear end clunk going over small bumps since I bought the car last year. mk2.5 focus with 1.8 petrol engine. Its like a light metallic 4 or 5 knocks like something is loose when you drive over small bumps

So far I have replaced -

Springs and shocks all round

Rear trailing arm bushes

Lowered 30mm on eibach pro springs with bilstein b4 dampers

New febi rear top mounts

New upper and lower rear control arms (not the one the spring sits in)

New rear lemforder end links

I have even removed the entire rear anti roll bar assembly but the noise is still there so it is not that

Fixed all loose heat shield mounts

checked the hand brake cable

checked boot hinges

The only thing that hasn't been replaced on the rear sub frame at this point is the main control arms where the springs are seated. Could be that but at this point I feel like I will never find the source of the noise

Anyone got any ideas? I have read every single thread about clunking focus mk2s and mazda 3s but I am absolutely stumped now

It makes me hate the car. Really need to get this sound gone.

 

I had an annoying 'clunk' but was cured by something you've already done, the top mounts.

 

I've also had the rear subframe replaced but this was due to alignment issues, it was whisper quiet!  

Sorry I can't be any help to you, good luck...

As you've replaced all the usual parts, I have a few 'daft' suggestions.

1 - Remove spare wheel & tools for a few drives.

2 - Make sure there's plenty of fuel in the tank.  The level float can rattle against the bottom if you're low on fuel.

3 - Plug in all 3 rear seat belts

4 - Try to 'rattle' the rear seat bases and backs to test if any are loose.

5 - Try to rattle the spoiler, tail lights and parcel shelf.

6 - Try to rattle the tailgate trim - or ideally remove it altogether to check for anything loose inside the tailgate.

10 minutes ago, TomsFocus said:

As you've replaced all the usual parts, I have a few 'daft' suggestions.

1 - Remove spare wheel & tools for a few drives.

2 - Make sure there's plenty of fuel in the tank.  The level float can rattle against the bottom if you're low on fuel.

3 - Plug in all 3 rear seat belts

4 - Try to 'rattle' the rear seat bases and backs to test if any are loose.

5 - Try to rattle the spoiler, tail lights and parcel shelf.

6 - Try to rattle the tailgate trim - or ideally remove it altogether to check for anything loose inside the tailgate.

Good list, I did all that before it was professionally diagnosed that the top mounts had gone, being an amature, I'd have never have caught it...

2 hours ago, TomsFocus said:

As you've replaced all the usual parts, I have a few 'daft' suggestions.

1 - Remove spare wheel & tools for a few drives.

2 - Make sure there's plenty of fuel in the tank.  The level float can rattle against the bottom if you're low on fuel.

3 - Plug in all 3 rear seat belts

4 - Try to 'rattle' the rear seat bases and backs to test if any are loose.

5 - Try to rattle the spoiler, tail lights and parcel shelf.

6 - Try to rattle the tailgate trim - or ideally remove it altogether to check for anything loose inside the tailgate.

Thanks man, I'll give your list a whirl. If it turns out to be a tail light or the spoiler I will be buzzing but massively dissapointed in myself at the same time hahaha

Have you replaced the rear droplinks?

Maybe what you mean by the Lemforder end-links but worth asking 🙂
 

I used to have a knocking noise from the rear - fixed by changing the ARB droplinks even though the ones that came off seemed to look ok (apart from the hacksaw work needed after one of then inner hex’s rounded off)

3 hours ago, troy45 said:

Have you replaced the rear droplinks?

Maybe what you mean by the Lemforder end-links but worth asking 🙂
 

I used to have a knocking noise from the rear - fixed by changing the ARB droplinks even though the ones that came off seemed to look ok (apart from the hacksaw work needed after one of then inner hex’s rounded off)

Yeah I replaced them with lemforder ones but that didn’t fix it 

 

I even removed the whole rear ARB assembly today and drove around for a bit but the noise was still there so it can’t be anything rear ARB related unfortunately 

 

my next move is to re seat the rear springs and change the main control arms because I might as well at this point 😆

 

if that doesn’t fix it in gonna drive it into the nearest lake and call it a day 

Forgive me, but... if none of the above suggestions work ... 

... just turn the radio up and pretend the clunk doesn’t exist 😁