hoodpad differences? - PeachParts Mercedes-Benz Forum

samiam4 · #1 12-13-2002, 12:51 PM

What's the difference between with and without a heatshield?

THe price is 2X! Mine is a non-turbo, but if noise or longevity is better, I'll spring the extra $30.

Michael

rwthomas1 · #2 12-13-2002, 01:27 PM

I was thinking about the heatshield model as mine is a turbo but then I did a search and saw what rebootit did with the fiberglass blanket from McMaster and that got me thinking. I have also looked at the hoodliner from Dynamat. Looks pretty good and is @$50. I have used Dynamat products before and it is really good stuff. Likely that is the way I will go. My concern with rebootit's install is the material is only rated to 180*F?? Seems a little low as the motor runs at about 180*F doesn't it? RT

JPL · #3 12-13-2002, 01:28 PM

Hey Samiam4

The turbo specific hood pad offers heat protection to protect the paint on the hood from stress because of the turbo's operating temp.

At least thats what I've heard. Perhaps someone more mechanically savvy than I can give a more detailed explanation.

J

samiam4 · #4 12-13-2002, 04:02 PM

rwthomas,

I heard your reservations with rebootie's installation. 180F doesn't seem that high... he also installed it with 3M 77 which isn't rated that high temp.
I was always told to use 3M 97? Anyway, the similar product but for higher temperatures. Somewhere, I saw someone that had installed a heavy material. He had expoxied tie strips to the inside of the hood. Looked like a really nice for sound and heat.

Michael

rwthomas1 · #5 12-13-2002, 05:26 PM

I think the Dynamat hoodliner has the adhesive already on it.... At least the regular dynamat does. I have seen it for @$50 on the web so it would be cheaper than the "factory" thermal hoodliner and not require any extra glue. Seems like a better deal to me. RT

Holson Adi · #6 12-13-2002, 09:22 PM

I thought the 'heat shield' mentioned is what seems to me a thin aluminum (aluminium.. :p) foil above the air cleaner?

rickjordan · #7 12-14-2002, 07:28 PM

The "heat shield" is nothing more than a section of foil. Also the shield lines up with the top of the aircleaner. Being it that the turbo is under the aircleaner, you would think that would be a sufficent shielding.

lrg · #8 12-14-2002, 08:05 PM

FWIW, on the late California cars the air cleaner is moved forward behind the right headlight so the turbo is exposed. On those I'd go the route of using the pad with the heat shield. On the others with the air cleaner over the turbo I'd agree with Rick, it's probably unnecessary to have the heat shield.

DieselHead · #9 12-14-2002, 09:29 PM

I replaced my hood pad a few months ago, and usually, when I don't know what to buy, I tend to choose the more expensive option. The heat shield seems to be a total waste of money. It looks a bit cooler, but who cares right? I'd save your money and use it for something more useful.

Alex

Peyton300TD · #10 12-15-2002, 02:11 PM

i have the hoodpad with the heat shield. yet i think it is silly because it is not the hottest part under the hood and that part of the hood doesn't receive the most stress from heat.

if you hold your hand over the engine while it is hot, clearly areas around the block are much hotter.

eric

#11 12-15-2002, 07:59 PM

I noticed I said I used 3m77 and was wrong. I used the high temp super strong 97 stuff. (went and looked at the can) I live in central FL. It is HOT here in the summer. Average of around 97 with a sun hot enough to melt most anything. I am sure the average underhood temp in the summer was well above 180. The material I used still looks new. Has not come loose, not sagged and not melted. Fiberglass is GLASS. It takes well above 180 to melt. It's the same stuff used inside your hot water heater, oven, etc. I don't see it bursting into flames in an underhood application. MB used an open cell foam rubber material. I doubt it had as much heat resistance as any fiberglass material.
I went with the blanket material because I had a use for all the leftover stuff here and there in the car for noise control. Also figured the cost was close to what a MB pad would cost but like I said it was nothing more than foam rubber. I can buy a 5x10 2.5" thick sheet of that for under $20.00 here local.

BobK · #12 12-16-2002, 07:10 AM

Daughters' 300D just got a new hood pad last month. Bought MB model with heat shield in it. Didn't cost too much. Previous pad had heat shield too, but had been installed wrong side down . Heat shield was against hood on driver side. New pad looks like a million bucks. Really dresses up engine bay. Now I have to replace them on my 560 and wifes' 190. If I do them soon, can of glue might still be usable!

#13 12-16-2002, 10:03 PM

If I am not mistaken, the hood pad with the heat shield was originally installed on 1986+ SD and SDLs. As these engines had the dreaded "TRAP OXIDIZER" which produced an enormous amount of heat. Being mounted on top of the exhaust manifold it was very close to the hood and insulation blanket. I wouldn't be surprised if the heat shield was installed so as to prevent a fire if the insulation blanket were to touch the TO.
I guess the metal would also help 'spread' the heat so as not to burn the hood paint too.
My $.02.

Bill.

Dcraig · #14 12-17-2002, 03:40 AM

I agree with Irg. My previous 1985 300CD (a CA car) had the hood pad missing. My turbo was very close to the hood, and it did crack the paint in a circle the size of a softball. I bought the pad with the sheild.

On my current 1985 300CD (another CA car), I plan on buying another sheilded hood pad. No blistering yet even though there isn't a pad on there (I think a turbo issue). Older models shouldn't need it.

I think the sheilded pad is only $40.

Craig

CamelotShadow · #15 09-17-2007, 01:59 AM

The hood pad with the self adhes is interesting Dyna...

Mine appears to be a waffle foam rubber
Its disintergrating.

My Volvo has a sort of felt
Its still in great shape.

I'd like to find something like the Volvo material
a wool felt or something that won't break down so easily from the heat

My ngine is running close to 100C
thats 212!