Gunite

Has anyone looked closely at how our engines are encased in sort of a tomb or thermos like housing. I noticed when the hood is completely closed there are no outlets for the air to escape anywhere. I originally thought the air ducts on the hood would allow hot air from the engine bay to escape but after close examination that's not the case. Those vents are behind the engine enclosure and do not allow hot air to escape. I suppose Mercedes did this strictly to mute engine noise.
Here's what I did. I removed the hood liner to allow heat to radiate through the hood. I removed the rubber insulator surrounding the engine compartment to allow hot air to escape out the hood vent. The whole thing took about 15 minutes.
I went for a spin and noticed the engine temp took longer to reach the usual 90C. This engine sounds simply beautiful with these items removed. I cant describe it just do it and listen for yourself. I think Mercedes made a mistake insulating the sound of this engine and in turn trapping heat buildup in the engine compartment. I can now feel the heat radiating out the hood vent after I shut her down.
It looks like you can take this mod a few steps further by re routing some of the wires under the hood vent and removing the insulation surrounding the engine compartment and placing a few holes to allow even more heat to escape and make its way out the hood vents.

Joe

regor60

The only thing I'd be concerned about is whether the hood gets markedly hotter and consequent effect on the paint

MB Fanatic

The yellow arrows you have drawn onto the picture are a mercedes trademark. Its the double firewall. I would sure as hell not remove that from teh car, god forbid something were to go wrong with the car. Also removing the heat shields from underneat the hood will have an adverse affect on you paint. It might discolor or crack if it gets too hot.

AMG2GO

Gunite I respect your enthusiasm in doing these mods, but don't you think that the engineers as MB have thought of all these heat issues already and determined what needs to be there and what doesn't? you are removing parts off a $90,000 car... hood paint may be just one of the problems... I don't know if I would be doing any of this if I were you. This isn't a Mustang you are messing with. The car is an '05 with full factory warranty, why do you feel the need to mess with anything at all?

Gunite

I appreciate all your concerns and comments. The paint issue is something I would like to get some more opinions on before I'm convinced removing the hood insulation is detrimental.

As far as messing around with a $90,000 car and possibly voiding my warranty is concerned, what then do we say to all the members who have installed after market pulley's, ecu reprogramming, evo cooling kits, headers, exhaust systems and on and on.

If Mercedes engineers put the double fire wall there to protect me from a possible engine fire I'll take my chances and simply rely on the first fire wall. I really didn't remove the fire wall only the hood insulation and the surrounding rubber seal to let the heat escape from the hood vent.

I still not convinced that what I did will have any after effects other then reducing under hood temperatures as opposed to increasing them with an aftermarket pulley and upping the boost on the engine. Again this was only a 15 minute procedure that's easily reversible.

I would like to urge someone else to try this and report your finding. Even if its only temporary. I really think you'll be amazed at the amount of heat that's being evacuated from the hood vent once these items are removed.

Joe

vraa

What kind of temperature drops are you looking at?

As for the heat affecting the paint, isn't the paint itself baked on because of the ceramic clearcoat?

medici78

Why not install thinner insulation, rather than eliminate all of it? The hood would be ridiculously hot without any insulation, so any water that would be heated, could cause potential paint damage, not to mention the heat alone. On the flip side, I know there's guys out there with turbocharged cars who safely run no insulation. So who knows, maybe it would be fine. Its your car, so do what you like and let us know how it goes.

MHaynes772

How do you remove those #*&$#^ little clips!!!!!!!????????

Gunite

I'll do some temperature drop testing next weekend. In all honesty the paint feels much hotter after sitting in the sun all day. After a couple of hard runs, and then shutting down I can still rest my hand on the paint. Don't forget, now as the car is sitting the heat is rising and escaping form the hood vent.

Removing the clips is easy. Just wrap a little electrical tape around the tip of a flat head screw driver, carefully pull back the insulation to expose the first clip and poke at the little nipple on one side while gently pulling on the insulation. Then poke at the other side where the second nipple is and it should release. Continue this until there all removed and then remove the plastic piece that covers the vent. Now just remove the rubber gasket surrounding the engine and this will create a gap for the heat to escape out the hood vent.

Joe

AMG2GO

The insualtion is there more as a fire and noise blanket. I don't think it will affect the paint short term. You may miss it if you have an accident... heaven forbid something does go faulty and cause a fire, MB can void any responsibility of damage because you removed the insulation blanket. I haven't seen it myself but the rubber seal may be there to keep rain water off critical engine parts... if its a seal, it may be there for several reasons.

I guess to me the real questions is, WHY? What are you gaining by doing this?

Obviously engine mods are done to make the car faster with measurable results... even though some of them are very questionable.

Its not like the car is having heat soak problems and the engine is stalling... that the A/C is not working... or that plug wires are melting... I have no doubt it gets hot under there.... but that's why MB runs their cars in death valley for weeks. If there was a real issue, don't you think that some of the hundreds of MB engineers would have figured it out? If something is going to fail or power is being robbed, don't you think one of the engineers would say "hey we should remove that blanket or change it for a thinner one"?

My point is that $90K gets you a well engineered car. Especially in a Mercedes. I would be shocked if there is a real issue that was just neglected and now a pair of pliers is solving the problem. I have never seen Brabus, Renntech or Kleemann remove this, even after mods that create more heat... There may be a valid reason for that.

Gunite don't take me the wrong way man, I am not trying to knock what you are doing... I have done many things like this myself in my race cars... and I like to tinker myself as well... so I am with you... but I don't see the benefit of this one.

vraa

But AMG2GO, a lot of people are experiencing heat soak.

AMG2GO

What exactly is happening? heat soak is a term generally used when there is so much heat under the hood that the fuel inside fuel lines starts to boil... and the car then runs rough and stalls. I am sure that is not what is happening here is it? what is the problem you guys are having?

vraa

Oops, from what I've read on the forums, heat soak is just the heat getting to the supercharger, and the efficency of the supercharger .. well.. plummenting so low that the car no longer feels like a true AMG.

MHaynes772

When my car gets hot, it stalls, has happened 3 times since I've had the car in the past 2 1/2 weeks.

MB Fanatic

Get the Evo cooling system upgrade if you want to cool your engine.

MHaynes772

Yeah, I want to, but damn that thing is expensive! Every upgrade for our car is expensive. I guess they figure if you can afford the car, you can afford high priced upgrades.


GUNITE- Well just did it, so what should I keep an eye on and whatnot.

MB Fanatic

If your car catches fire, dont expect it to be covered under warranty anymore, thats what I would expect lol. I hope you didnt remove the insulation from the firewall.

MHaynes772

Okay Okay Okay...I put it back on...If I didn't have bad luck, I wouldn't have any at all. So it's back on...Sorry GUNITE.

Also- I have a 3m clear bra, don't want to take any chances with discoloration.

Evolution Marine

Why not just remove the vent cover and rubber moulding at the top edge of the firewall and leave the hood insulation? Also, one thing to consider, is the source of air for the A/C system and interior venting system most likely comes from that same vent area. Removing the rubber moulding from the top of the firewall and the hood vent cover allows the hot air from the engine compartment to mix with the intake air for the A/C system and interior venting system, thus letting in engine smells and reducing the A/C system efficiency. Let us know Gunite if you notice any effects like this. - Bob

Gunite

It would be nice if some tuners chimed in here and gave us their opinion on removing these items because I'm still not convinced I created a worse situation inside my engine compartment by lowering temperatures and allowing heat buildup to escape. Do you really think I created more of a fire hazard or increased the risk of causing fire by removing these items. Please explain this in detail. If this wonderfully engineered $90,000 dollar car has a history of engine fires I'm selling it tomorrow.

I didn't notice any adverse effects on the A/C. Since the hot air is continually rising and escaping I doubt its mixing with the A/C unit there on the left. How do other car manufactures deal with this when they don't encase the engine inside a thermos.

I considered only removing the rubber molding and plastic cover over the vent but after feeling the temp. of the hood after making some runs it just doesn't seem like an issue.

I appreciate the feedback.

Joe

stevebez

Personally I would not do this - paint issue and also electronics in between the two firewalls have been isolated for a reason - temps and water.

I dont think the risks are worth this one... but thats just my 2c.

Rgds Steve.

benzmodz

Why bother having a hood at all. Just take it off completely.

Rafal

Or get a C/F hood with vents and get your head chopped off ..... :v

vrus

Hey Gunite,

I also thought of doing this. I've removed hood insulation on a few of my cars before but because of the high heat the motor generates and the fact that my car is black, I didnt remove it for fear of causing some paint bubbling.

I think it's a good idea personally and was thinking of pulling it off and coating the hood with some thermotech heat wrapping.. It is much lighter than the factory stuff and I believe it also acts as a fire retardant.

I see you have a black car also.. I am feeling a little more confident now that you mention you didn't notice an increase in hood temps.

Let me know what you think in a few more days of driving with it off.

AMG2GO

Guys, can someone tell me what the real problem is? I mean I know it gets hot there, but is something failing? I would think if there is a genuine problem MB would have a fix.

There are all sorts of fixes, but they all remind me of the things you do on a chevy... not on an E55. If there is a genuine problem it needs a genuine fix.