Unexplained clunk over bumpy roads?

[HowardRoark 42]

I am hearing a loud "clunk" when I hit a hole in the road.   About 2 years ago, I fixed the loose rear wooden bulkhead problem (that sits between the seats and the engine) that is associated with Esprits, and that solved a huge problem.    I don't think that it is this time (unless the bolts in the wooden bulkhead came loose again).

 

The noise seems to be coming almost from the passenger door area, but it is hard to tell.  The door is not loose.  The battery is screwed down well.  The seat is not loose.  I am just trying to find out what it might be.   Any ideas?

 

thanks!

[J400GED 1]

Possibly wiring harness connectors jumping around inside the door maybe?

[Mark Blanchard 1,657]

Does you car appear to be lower to the ground than normal?  Sagging springs can sometimes do this.  A sign is to lift the front bonnet and see if there are hair line cracks around the wheel arch.

[Günter 28]

if it is 'from the door' -undo the inner door-card ..inspect the mechanic/function of the actuating rods, if possible add some foam there to stopp them 'dancing' in there latches.

-test for all the functions, especially for the auto lock/unlock prior to refit of the door card !

 

And of course, inspect the outer door handle (the ordinary Opel/GM one)

..it is a type of cast metal [zinc die-cast, if I recall right] that can act hard against the suround there if it does have to much play in its bearing points ..and that makes odd sounds inside the cabin on most bumps too.

 

To test it, prior to dismantling of the whole door handle mechanism -just tip with the finger from the underside 'on the edge' upwarts, with closed door and the doorhandle not on a hard grip. 

 

Does it move upwarts in its position, do you hear a slight 'clonk' if you push it upwarts on the edge, with the finger tip ??

 

-there is also a small rubber 'dot' ..that keeps it from making to hards sounds if you for example release it.. after you opened the door (so if you let it snap back there) -this one sits there (glued) on the outer hadle suround ...

 

 

 

*********

 

other point to watch out is:

-the window frame and side window slots, fitted to the inner door-beam ..are those tight and into position correctly ?    

-there is a hook that catches one of them, with a plastic insert to stop 'metal to metal' sounds as well

 

 

***

are there any pieces hanging around from the mostly totally roten window-slot/rain guard cover   ..you can feel those if you grap behind the side window if it is in its most upward position, and if you have small hands to reach the area there under/behind the lower end of the glass  .. is there anything coming loos already ?

 

@Mark. the wheelarch each side front and rear, this is covered by wheelarch-extensions there on S4s/V8 bodied cars

Edited February 18, 2013 by Günter

[Rob C 8]

You may have a Radius Arm mounting failed....been there twice...like now. Naf

[Günter 28]

Rob ..not totally sure on the layout

 

..but the radiusarm is there for 'momentum compensation' ..right ?

 

so with lots of power from your drivetrain, good brakes and tires  -no wounder   ..right

[MPx 279]

Not sure if its the same on the later cars....but on the G cars, the body is not that well fixed to the chassis and various screws/bolts can come loose over time. Could ber a bit of lift off and touch down again!

[Günter 28]

you can be sure -loose bolts and nuts an various fixing exist on every (oldish) Lotus ..it is a main feature

[HowardRoark 42]

Thanks for all the great info.  I took it in and had my guy do 2 things: re-bolt the wooden bulkhead (which did help), and replace the engine mounts, as a guess from me (just from what I have read about the issues with the V8's).

 

WOW.   Replacing the engine mounts made a HUGE difference in the overall feel, making it MUCH more solid and enjoyable to drive.  It is like driving a different car now.  Before the mounts were replaced, I thought I was paranoid almost as i sometimes thought I could feel the engine move as I accelerated.  I think it was!   If you have a V8 and haven't check the mounts, you should check them.  Mine were absolutely rubbish and cracked.

 

Now I hear one other little rattle/buzz at idle once in awhile.  I think it may be the heat shield.