Hi,

Has anyone ever had issues with Delphi OEM front shocks on an L322 making horrible vibrating knocking noises?

Reason I ask is because I have an annoying knocking noise coming from the front that is driving me potty. It sounds just like the anti-roll bar is loose in its bushes, however they are fine. So far I have,

1) checked anti-roll bar bushes - they are fine
2) replaced the anti-roll bar link arms with good German ones (forget the name of company)
3) replaced front lower arms and polybushed the inner bushes.
4) I can see no play with crowbar, or marks, on the rear arm.
5) there is no play in hub bearings.
6) recently new discs and pads, it is not the disc shield tizzing.

The noise only really occurs when hitting bumps like potholes, kerbs, rough track, but doesn't happen driving down cats eyes for example.

It actually sounds like something loose due to the way the rattle vibrates, hence the initial thinking with regard to a loose anti-roll bar.

Any thoughts most appreciated!

Thanks

Richard

Is it just one clonk or a series of them... can you describe the noise a bit more??

Did you tighten the lower arms, and anything else you've done, with the weight of the car on it??

Check the strut top mount for wear/tightness...

Don't think you will find the polybushes will last very long, tried them in the past and they never last as long as original bushes and also they restrict suspension movement.... Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

thanks Pete, you are probably right with these particular polybushes. In the past I've fitted them to a classic, a P38 and a Disco 2 and, beyond 10yrs later, they are all going strong (albeit with new owners), and worked wonders. However, I'm of the thinking that they won't last too long in this particular case. The lower arm was also a complete pain to fit, as the central tube pushed one half of the bush out, even under 20tons of press. Then had to use a jack to force it into place on the chassis. Never had so much trouble with a polybush! I think the 'top hat' ends are going to wear somewhat unduly too. I think I might just have to resign myself to replacing them every MOT, as they are only lasting me about a year. That and the rear hub top bushes pushing 2yrs if I'm lucky.

The 'clonking' is a series of knocks, or rattles. Its most prevalent when driving up a 1/2 mile dirt track, or in potholes. If I go over a speed bump I hardly ever notice it. When it does rattle it is just like what you might imagine if the anti-roll bar didn't have any bushes and was allowed to rattle/vibrate undampened.

So its not a 'clonk', but more an undampened rattle.

The lower arms were tightened with the weight put back on the car, as per RAVE instructions.

I have wondered about the strut, but they are only 2yrs old and were fitted by a very reputable independent 4x4 garage (who have also relieved me of a small fortune this last year due to sticky valves, 6 replacement injectors, stuck turbo vanes, the list goes on!). I've never had any issue with any Delphi shock before, plus the fact I don't get the noise when they are going over road bumps.

When its been jacked up I've not noticed any movement in the strut, how might I specifically be able to check the top mount, or would it be obvious if there were any movement?

I'm currently waiting for a bluetooth microphone/transmitter and headphones to turn up, so I can hopefully stick it underneath to find the source, as hanging out the window with the bonnet up hasn't helped.

cheers