W124 E220 ticking/rattle

[jeffreyli86]

Hello all,
I have a 94 W124 E220.. Immaculate (restoration project just finished), 40k miles, automatic..
The car makes an outright racket (being a tinny rattle noise going "tick tick tick tick") whenever you reach 2000rpm and it speeds up as the engine revs up (being a slower tick tick tick at 2000rpm and a quicker tick tick tick at 3000rpm). The rattle fades away after 3000rpm. It is most noticeable when you are in a higher gear (say 3rd or 4th) and accelerating hard within the 2000-3000rpm rev range.. The noise is less noticeable (but still is) if you back off the throttle.. And when you are slowing down and have your foot off the throttle, the noise is less apparent.
The car does have an aftermarket exhaust (custom pipes and Remus backbox for the W124) and no catalytic converter (not illegal in my country for cars of this age).
Any ideas?
I was thinking about some wrong material used in the exhaust pipes. Another idea might be the cam chain or tensioner? I'm really stuck on this one and it is an outright embarrassment.

Cheers

 

[Ellsy Tanners]

Does it sound like it is coming from the inside of the engine or exhaust?

 

[jeffreyli86]

To be honest, I don't know. My mechanic has driven it and he reckons it is from the exhaust however, I don't quite understand how the exhaust can make such a sound..

 

[jeffreyli86]

Here's a quick pic of my pride and joy.. Spent 4yrs restoring it..
Sorry about having to edit the pic, as the pic is supposed to be the property of a modelling agency , so please do not post the pic elsewhere

Cheers

 

[meanie]

Does it seem worse when the engine is cold?
If so check the exhaust manifold for cracks,and the manifold gaskets.
Where are you out of interest?

 

[jeffreyli86]

Does it seem worse when the engine is cold?
If so check the exhaust manifold for cracks,and the manifold gaskets.
Where are you out of interest?

I don't think it is worse when the engine is cold. It's just as bad LOL.
I'm from Hong Kong, but spent the most of my life in the UK.

Cheers

 

[meanie]

I don't think it is worse when the engine is cold. It's just as bad LOL.
I'm from Hong Kong, but spent the most of my life in the UK.

Cheers

Would I be correct in assuming that the noise is worse when the engine is under load then.

 

[Ellsy Tanners]

Awesome looking car mate.

It could be a exhaust blow as said above, or possibly its rattling against something underneath. It need to be traced by being listened too,to be honest

 

[turnipsock]

Does it sound like tappets?

 

[meanie]

Awesome looking car mate.

It could be a exhaust blow as said above, or possibly its rattling against something underneath. It need to be traced by being listened too,to be honest

If JeffreyLi would like to cover my expenses,I'd be very happy to go & listen to it & report back to you!

 

[Bolide]

Hydraulic tappets, cracked manifold or the exhaust bracket that mounts to the gearbox. I'd start with those

Nick Froome
www.w124.co.uk

 

[jeffreyli86]

Does it sound like tappets?

Definitely. I heard a tappety BMW 318iS at the garage the other day and it's more or less the same. However, mine only makes that noise during the 2000-3000rpm range

 

[jeffreyli86]

Would I be correct in assuming that the noise is worse when the engine is under load then.

Yep it is. Most noticeable when it is in say 3rd gear and I'm going uphill WOT. Is this starting to point to something in particular? :-o

 

[jeffreyli86]

Hydraulic tappets, cracked manifold or the exhaust bracket that mounts to the gearbox. I'd start with those

Nick Froome
www.w124.co.uk

Would probably have the car jacked up and check it over today, hopefully.. Are the tappets difficult to sort?

 

[jeffreyli86]

If JeffreyLi would like to cover my expenses,I'd be very happy to go & listen to it & report back to you!

LOL I'll get you a ferry ticket then!! See you in a few months LOL

 

[kth286]

Are you saying that the car has to be moving for the sound to appear - no tapping sound if you rev the engine whilst car is stationary??????????

 

[jeffreyli86]

Are you saying that the car has to be moving for the sound to appear - no tapping sound if you rev the engine whilst car is stationary??????????

Yep. And just a little update. Had the car at the mechanic's today and got the exhaust heat shield off. It was cracked but it was not the source of the embarrassing noise. Inspected the exhaust manifold and it seems to be fine. We then revved the car within the 2000-3000rpm range using WOT in short bursts. It seems that the resonator is the culprit. It's an aftermarket product and probably made in China (since HK is so close to the Mainland LOL). Will probably get that changed ASAP and see how it goes..

Is it possible for me to use, say, a BMW or Volvo resonator instead? I'm only concerned about the size since I will have the exhaust guys weld up the necessary piping.. I just tend to like the sound of BMWs and Volvos LOL

Cheers

 

[roofless]

it still might be a miss fire if it's only under load & clears at 3000rpm a sign of faulty coils or ecu & can be due to the loom decomposing..worth checking

 

[jeffreyli86]

it still might be a miss fire if it's only under load & clears at 3000rpm a sign of faulty coils or ecu & can be due to the loom decomposing..worth checking

Cheers mate. Loom and ECU has been changed at the dealer about 4 years ago, so I'd hope it is still OK since the car is otherwise performing flawlessly.

I will check the coils. Where is it and what are the signs that it is shot? The car pulls fine within that rev range though.

Cheers

 

[kth286]

what's the resonator exactly?