S320 CDI sound proofing...

[Kenwin]

Although a (very proud) new owner of a (April) 2001 S320 CDI, I find the car disappointingly noisy, especially starting from cold (sounds like a truck!). Can anyone provide advice on better sound proofing?

 

[Baron_Samedi]

Ear plugs?

 

[corned]

Firstly, I would ask if you are sure it has all its under-bonnet sound-deadening panels and engine compartment under-trays in place?

 

[Kenwin]

Thanks corned...

Will check. Sorry if it's a bit of a noddy question but is it obvious what they look like?

 

[Kenwin]

Thanks Baron_Samedi...

Ear plugs?

... but how will I hear the radio?

 

[Baron_Samedi]

Doh!

There's always a downside to every great plan

 

[Kenwin]

Thanks Baron_Samedi...

Doh!

There's always a downside to every great plan

... Ta anyway!

 

[corned]

The bonnet should have a large (probably black) 'cover' on the underside which looks like a fabric material, clipped on. If you can see body colour paint then it is missing!

The car should have black plastic under-trays under the engine and possibly extending rearwards under the gearbox. The front one should clip onto the front valance. I.e. if you look up under and behind the valance, you should not be able to see any engine compartment components. A quick look underneath should tell you all you need to know.

 

[renault12ts]

Someone, probably on here, said that the rubber boot on the steering column as it goes through the bulkhead can break and let noise in...have a look.

Of course the straight 6 cdi is noisy on start up...especially on these cold mornings.

 

[Kenwin]

Thanks again corned...

The bonnet should have a large (probably black) 'cover' on the underside which looks like a fabric material, clipped on. If you can see body colour paint then it is missing!

The car should have black plastic under-trays under the engine and possibly extending rearwards under the gearbox. The front one should clip onto the front valance. I.e. if you look up under and behind the valance, you should not be able to see any engine compartment components. A quick look underneath should tell you all you need to know.

Will check what you so kindly described.

 

[Kenwin]

Thanks renault12ts...

Someone, probably on here, said that the rubber boot on the steering column as it goes through the bulkhead can break and let noise in...have a look.

Of course the straight 6 cdi is noisy on start up...especially on these cold mornings.

...The car is quieter once warm but my previous car (Honda Legend 3.2) was whisper quiet at 6 years old and ~80,000 miles on the clock when I bought that (not so quiet in later years). Perhaps I'm being a little unreasonable to expect the same of a 8 1/2 years old diesel that has done ~122,000 miles?

 

[christopherwk]

Someone, probably on here, said that the rubber boot on the steering column as it goes through the bulkhead can break and let noise in...have a look.

Ah yes! Mine is loose. I didn't think it would make it any noisier inside, I'll have a closer look tomorrow.

 

[corned]

I have noticed that on my 211 as well - the black rubber boot at the base of the column is not attached and can be moved around.

After a very brief investigation I couldn't see anywhere to fix it; there were no clips, screw holes, etc in the rubber moulding, although I noticed that the moulding has a quite wide flange around its base. Is this supposed to simply tuck in behind the carpet, or something other than that?

 

[christopherwk]

I have noticed that on my 211 as well - the black rubber boot at the base of the column is not attached and can be moved around.

After a very brief investigation I couldn't see anywhere to fix it; there were no clips, screw holes, etc in the rubber moulding, although I noticed that the moulding has a quite wide flange around its base. Is this supposed to simply tuck in behind the carpet, or something other than that?

Yes, I had a look just now, and have no idea where it goes. It just flaps about. The carpet is stuck down so I don't think it tucks behind.

 

[prc]

Ok not an S but to quite the noise down a bit on my w203 added:

1- Dynamt dynaliner under the original equipment sound deadening (used the 1/8" variety). Also used behind A-pillar, door skins and B-pillar

2- Same as above but 1/4" under front carpet.

Helped quite a bit.

 

[corned]

Christopher:

Exactly like mine! You would expect to see some moulded screw holes in that bottom flange, or some kind of clip, but no - it just flaps about like you say.

In a sense I'm glad it's not just me, but on the other hand I find it very odd that it has no obvious method of fixing. I'm sure it would be better from a build quality perspective, and potentially safer, to have it fixed down to something.

Imagine getting your shoe caught on it when going for the brake pedal! Not that this has ever happened to me, but there is always the potential...

 

[Kenwin]

Thanks corned...

The bonnet should have a large (probably black) 'cover' on the underside which looks like a fabric material, clipped on. If you can see body colour paint then it is missing!

The car should have black plastic under-trays under the engine and possibly extending rearwards under the gearbox. The front one should clip onto the front valance. I.e. if you look up under and behind the valance, you should not be able to see any engine compartment components. A quick look underneath should tell you all you need to know.

... checked what you described. Looked fine and felt quite secure.

 

[corned]

OK - good news! Thanks for letting us know. At least everything is where it is supposed to be.

If nothing is missing, then either your car is making the normal amount of noise after all, or it is the engine itself which is louder for some reason.

Reasons for this could be wide and varied. However, quite a few people on here say that their CDI engines quieten down after a good application of injector cleaner - Forte, for example - and this seems to reduce the famous diesel clatter noise. I have no personal experience to go on - just anecdotal evidence from these hallowed pages. It can't do any harm, so you never know - it might just do the trick.

 

[Kenwin]

Thanks renault12ts...

Someone, probably on here, said that the rubber boot on the steering column as it goes through the bulkhead can break and let noise in...have a look.

Of course the straight 6 cdi is noisy on start up...especially on these cold mornings.

... Checked this today. Looked pretty untidy around there, not sure I felt any rubber but foam padding which I don't want to pull at too hard. Nothing flapping about but appeared to be incomplete with gaps (possibly through the bulkhead?).

 

[Kenwin]

Thanks

Yes, I had a look just now, and have no idea where it goes. It just flaps about. The carpet is stuck down so I don't think it tucks behind.

Like I said found nothing similar flapping about but found foam padding around the base of the steering column, apparently incomplete, i.e. gaps (possibly through the bulkhead?). Not sure how or how well secured as I don't want to risk pulling it too hard.