Noise on uneven road surface

[rmoconnor41]

Firstly the car has had lots of expert work at the rear end including beam bushes diff bush shocks and tank straps. Exhaust is not loose. Basically rear end is sound.

When I am forced to drive with the top up the car makes quite a loud clunking noise on uneven surfaces. Don’t hear anything with roof down.

I am not carrying a spare or the plastic tray and everything including the battery is secure in the boot.

Where else to check? Thanks

 

[John_B]

Check the push rod bolts are torqued up. I only cracked mine loose to check I was going to be able to undo them, obviously didn't tighten them up enough and then had the same symptoms you described

 

[rmoconnor41]

Check the push rod bolts are torqued up. I only cracked mine loose to check I was going to be able to undo them, obviously didn't tighten them up enough and then had the same symptoms you described

Thanks. I guess without a ramp there is no way of checking. However this isn’t something the shed would have missed when doing all the rear end work.
Doubt the MOT on Saturday would have seen anything.

 

[John_B]

You don't need a ramp, they're easily accessible with the car on axle stands, or even on it's wheels if you're just checking they're tight.

I'm sure the shed wouldn't miss them, but it wouldn't hurt to check. Like I say, the symptoms were the same.

 

[Duncodin]

Firstly the car has had lots of expert work at the rear end including beam bushes diff bush shocks and tank straps. Exhaust is not loose. Basically rear end is sound.

When I am forced to drive with the top up the car makes quite a loud clunking noise on uneven surfaces. Don’t hear anything with roof down.

I am not carrying a spare or the plastic tray and everything including the battery is secure in the boot.

Where else to check? Thanks

You say you don't hear it when the roof is down. Do you think that is because the clunking is being drowned out by the wind noise? For example going slow over an uneven road shouldn't be causing much wind noise so if there was a loose bush or anything you'd still hear it?

Or is it because the clunking actually has something to do with the roof itself?

 

[Jam03]

Could be the top mounts of rear shocks. Another strange one, but fits with the roof up is the strut that is meant to make raising and lowering the roof easier might have become separated like mine. That can rattle about. It’s on the LHS near the pivot point of the roof mechanism.

 

[rmoconnor41]

You say you don't hear it when the roof is down. Do you think that is because the clunking is being drowned out by the wind noise? For example going slow over an uneven road shouldn't be causing much wind noise so if there was a loose bush or anything you'd still hear it?

Or is it because the clunking actually has something to do with the roof itself?

I think that roof down is not masking the sound. Problem is car is so small that a rear car noise could be anywhere

 

[rmoconnor41]

Could be the top mounts of rear shocks. Another strange one, but fits with the roof up is the strut that is meant to make raising and lowering the roof easier might have become separated like mine. That can rattle about. It’s on the LHS near the pivot point of the roof mechanism.

I will Google that as the electric roof operates well.

 

[Jam03]

I will Google that as the electric roof operates well.

Probably won’t be that if you have electric roof and it works well.

 

[rmoconnor41]

Probably won’t be that if you have electric roof and it works well.

Thanks. Very hard to pin down. Anywhere underneath from literally under seat to end of exhaust which is a very short distance on a Zed

 

[Jam03]

Thanks. Very hard to pin down. Anywhere underneath from literally under seat to end of exhaust which is a very short distance on a Zed

Yes, I know what you mean. On my car, the exhaust back box is very close to the anti roll bar for some reason and if they touch, you hear it in the cabin when the roof is up. Roof down you don’t hear anything.
Before I had my beam bushes replaced, I had a knocking that got progressively worse. The beam was bottoming out on the push rod bracket because someone had jacked the car up on the push rod which had bent upwards. The top mounts were also knackered, even though the shocks had been replaced not more than a year before.
Hopefully you find the source of your noise.