Under bonnet foam liner deterioration. Again..

Started by carl888, 13 January 2014, 11:47 PM

carl888

Thanks for the tip Daniel, it's already on however.  Used some 130 degree contact adhesive, we'll see!

daantjie

If you can get that stuff Down Under it really is like gold, I love all things 3M 8)
You can use that 3M Super Trim Adhesive on carpet, weatherstrip etc, really good stuff.
Cheers
Daniel
1977 450 SEL 6.9 - Astralsilber

oversize

I would never use the factory stuff after seeing how poorly it holds up over time.  I was considering removing all traces of the original and painting it properly.  However I've heard another function of the insulation was to stop vibration and noise emanating from the bonnet which is a large, largely flat and unsupported panel
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

oversize

Quote from: carl888 on 17 January 2014, 03:30 AM
Finally, all the new rubber firewall grommets that I bought at the same time as the new hood pad...........................................are cracked.  So is it true that the replacement parts are inferior in quality to the originals? 

That's very disappointing and I'd hope MB would offer some sort of guarantee on their parts...  And source a better supplier.  They should last at least 10-15 years if not abused.
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

oversize

BTW the new foam looks much nicer.....  Good work!
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

rob280sel

On my girl the under bonnet liner is a leathery looking thing, I think its the original one. If so its 40 years old and looks in not to bad nic.

marku

The one on my 450 was disintegrating rapidly when I got it. The replacement I got from MB, quite cheap, was foam exactly like the other so I hope it lasts. The ones I have seen on the 126 look much better.
1974 450SE silver green/bamboo velour/green vinyl roof

koan


The new new bonnet line looks good Carl, I should get one for my 116.

As far as paint protection goes, I ripped mine off 10 years or more ago, it was falling apart, paint hasn't been affected. Clear coat is peeling in other places though but it is the original paint.

Boogity, Boogity, Boogity, Amen!

carl888

Well, the original hood liner seemed to last the best!

1974 280 SE
replaced in 2008 at 91,000kms.
replaced in 2015 at 109,000kms
open cell type

1980 300 TD
replaced in 2007 at 596,000kms.
Similar style to the above and holding up well.
open cell type

1982 280 SE
replaced in 2006 at 74,000kms
different construction to W116/W123 version, has outer cotton liner, holding up well.

1985 380 SE
replaced in 2012 at 104,000kms.
different construction to W116/W123 version, has outer cotton liner, holding up well.

Moral of the story:

1. The original fitment at manufacture is the best quality
2. Buy a 300 TD!

Mark, the rubber components I bought for the firewall in 2006 have all perished.  The only one that still looks good is the rubber gland around the fuel filler neck and the little rubber stops for the fuel filler door.  The others have all perished and look as bad as the ones on the car when I bought it.  I've kept samples of all the deteriorating rubber and plan to send them to the classic centre for comment.  It's not like the rubber is being heat cycled regularly with the nominal mileage on the W116 since replacement.  Annoying!
   

andrewk

A little bit of research as i'm in the process of replacing the hood/bonnet lining foam. It seems to be the original foam and has turned to dust, the free Chlorine from the chloroprene foam has also caused corrosion and pitting on many of the metal parts in the engine bay. Not good.

The adhesive MB use is Teroson (Terokal) 2444 made by Henkel, Germany. The foam part that is available locally is from Febi and looks to be of average quality. I bought this piece for around $130 AUD but haven't asked MB or an OE parts supplier if they can obtain it, or how much it costs for an original part. I assume very expensive, or not available. Given they are asking $1300 for a door or trunk seal, I assume 500-600+ for a hood insulation panel, if they actually have it.

I'll review the formulation of the 3M adhesive and see how it differs from the 2444.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

dima

Good afternoon everyone!  I used Germeton A15 sheet material, which is very similar in density and composition to the original.  The size 1000*750 comes with an applied adhesive layer.  Works great for 3 years now!

Jan S

Used standard aftermarket pad with strong adhesive 3M 08090.

So far so good, time will tell ....
1975-mod W116 450 SE with 6.9 engine

Zimmersci

Heat also must be detrimental. When you bring you car into the garage after any trip, open an lift the hood to promote cooling, it'll be good for other soft components as well.

goldacre

I to do the bonnet lift after a long drive in the heat, just drove to Carnarvon (Western Australia) in 42oC heat for 6 hours in a modern diesel SUV and first thing I did was pop the hood when I arrived and parked up... this was a trick I learnt off an old bloke when I travelled across the Nullarbor in a petrol car to prevent the fuel vaporising in the carby. The best part of that was the amount of people who pulled over asking if I needed any help  8) bless them  :-*

G
12/1979 450 SEL 148K on clock (museum piece)
12/1986 Lotus Esprit Turbo 87K on clock 'Darling, look what Q has brought for us, isn't it nice' :)