W124 E220 strange engine noise - suggestions needed

[IMD]

Hi all, Merry Christmas to you all.

I have a L plate E220 W124 estate, with 155000 miles, which I've had for 6 months now. Brilliant car, which has taken me a few thousand miles without any trouble. The thing is, there is a strange noise from the engine, which is quite noticeable at tickover.

The noise is a kind of repetitive cycle, the only way I can explain it, is to imagine the noise a train makes when rattling over tracks.... tickety tick, tickety tick, tickety tick and so on!

The car drives perfectly and the noise cannot be heard when driving, but when stationary, it sounds quite obvious, both inside and outsice of the vehicle.

I had some work done at a Independant Merc specialist a few months ago and he initially thought the noise was the water pump, so he fixed that, but it wasn't! He said he listened carefully to all parts of the engine and couldn't work it out....something he hadn't heard before. He said that it could be something to do with the timing chain, but to check, would obviously cost a fair bit of money. I don't want another exploration that doesn't solve the problem. I'm looking to keep the car, but am worried that if I need to sell at any point, it will sound like a bag of nails, when it drives faultlessly.

I'd appreciate any suggestions that you might have. I'm in Brighton, so any local 'experts' who you could suggest would be appreciated.

Thanks

Ian

 

[television]

Any skilled engineer could tell the difference from a timing chain to the tensioner.

The dampers on the idler assembly can make a distinct rattle, and easy to check, where as the idler wheel makes more of a ticking sound.

Using a large wooden handled screwdriver this can be used as a stethoscope by putting the blade on various parts and the handle to your ear. Do take care of the fan

 

[bolide]

Who did you take it to in the first place?

I'm sure that Alan Robertson in Hove (01273 770838) could tell you what it was in no time flat

Normally if it's noticeable at idle it's the belt tensioner or tappets

Nick Froome
www.w124.co.uk

 

[IMD]

Cheers Nick,

I'll give Alan a call in the New Year to give the car a once over. It needs a service soon anyway so he looks like the man. Thanks.

 

[Chemicalal]

Bit of a resurrection here. I have an e220 w124 estate with 151k and it runs perfectly, however it seems to have recently developed an intermittent (quiet) ticking noise. It occurs when you put the car in D or R but nothing in P or N. Its therefore only really noticeable when at lights or when I pull up to park. As I said its pretty quiet and only happens sometimes, but worried that its the start of something sinister. Going in for a service in 2 weeks and would love some prior pointers.

 

[grober]

May still be the poly V belt tensioner. Engine load characteristics will change in R or D which may effect revs slightly. Its usually the little bushes at the ends of the small damper [ mini shock absorber ] that stops the tensioner from chattering. Test by [a] pressing on the damper to see if it quietens down with the engine running [ watch your fingers!!]- taking off top mounting bolt [ on cylinder head]- engine off and see if there's any play on the lower bush on the tensioner body as you move the damper by hand. Easy DIY to replace if bushes are worn but the lower bolt can be tricky unless you take off the tensioner itself first .

 

[Chemicalal]

Cheers Graham, this damper you mention. Could u explain/show me exactly where its situated?!
Sorry for being a non-mechanical annoyance.
I know its somewhere along the fanbelt btw.

 

[Chemicalal]

Sorry Graeme!!!
With a first name Alasdair I'm normally very sensitive to mis-spelling names!

 

[kth286]

you will not have the damper on your late model.

rattles on e220 of that generation are often exhaust heat shields
coming loose because of rusty fixings.

the ones closer to front of car check first.

use larger washers to refit properly.

 

[grober]

Its item 29 here. BELT TIGHTENER ENGINE COOLING SYSTEM kth286- I have one on my 96 220 coupe? picture below you can see the top of the damper attached to the thermostat housing

Deffo worth checking the thin heat shields surrounding the exhaust down pipes also There to help build up heat to the catalytic converter quickly.