E55Greasemonkey

Marc may have been running in EC mode (compressor off) ?

I'm just of the opinion it may be a moot point, also maybe the increase in temps was the car getting progressively hotter as it warmed up, as in, the heater case getting warmer internally, or the firewall, etc..There are a lot of variables here. Even with the shield in place, the area around the cabin filter (sheetmetal) will get progressively hotter as the car sits at idle, to a point. So, not quite sure about the real effect here. Either way the A/C will still cool inside. There is no doubt some of the hot engine compartment air is mixing with fresh air, how much is debatable, you'll see in the video. But, in reality, compared to most other brand cars, the A/C intake gets some hot air from under the hood and around the cowling as they are not tightly sealed like the MB design, and are usually located at the base of the windshield behind the hood.

E55Greasemonkey

To prove this theory, you can block off the cabin intake and then the underhood temps should not drop

I think the ultimate solution here is to find a way to keep the cabin air intake section separate from the center of the grill, for example extending higher the rubber seal, so it presses against the bottom of the grill,but easier said than done due to the design in that area.

hpV12

I agree it's a moot point. But I'm entertaining this "con" in hopes of shedding light on the issue to those who haven't done this "mod" and are on the fence, so to speak. Because I feel it's a great mod with little if any negative side effects and to be put off by false and misleading information is a real shame given the benefits of doing it..

marc.l

That would be a good idea seriously carbon monoxide poisoning is not a good thing , you won't smell it , you will just drift slowly off to sleep . A different story but quite a lot of people die from it in the uk every year , last one I can recal was a family camping using throw away charcoal BBQ , they thought it had gone out , put it in the tent and it killed there children .
You will ask what's the risk of cracking an exhaust manifold or having an exhaust leak under the hood ? Pretty low I guess , but not a risk I would take !!! And tbh I think if you did and caused a problem to a passenger you would be on a manslaughter charge , is it worth the risk for a drop in under hood temps ?

E55Greasemonkey

Vids are up:

The outside temp was about 90F, engine fan running at about 70%, hood liner and panel removed

PACougar

To each their own, if you are that concerned about it you shouldn't do it. I think you're taking safety to an extreme. Even though you can't smell carbon monoxide you very much can smell exhaust and hear it. I'd say this is very low on the dangerous chances myself and others take in life. Hell, getting into your car and driving it on the road is way more dangerous

E55Greasemonkey

It would have to be a huge exhaust leak to be worried (aka open headers) , and further more there is still a large amount of fresh outside air being sucked in as well....

jcjmw

Wow! That is facinating! Thanks for doing it and showing us!

cij911

Maybe we are all saying the same thing, but the videos show exactly what Marc and I said they would - when you are standing still the the fan creates the high pressure zone and forces the air out of the grill. I would be very surprised if the fan forced the engine air out when the car was moving at anything more than 45 mph (or so) - my guess is the lowest pressure zone is under the car and most of the hot air is pushed (via the fan and velocity of the car) under the car (low pressure zone). The video also validates the left side will draw air (and will do so even more when the car is moving).

I will try to get my video (car moving) up before the weekend. Good stuff

PACougar

I think the key is when you're driving at speed cold air will be forced down through the hood and then out the bottom of the car. Regardless of whether heat is escaping through the vent or cold air from outside is being forced into the engine compartment through the vent the same thing is being accomplished, a cooler engine compartment.

cij911

Possibly ...Some of the GM cars used a raised cowl for cold air intake

Wouldn't that be interesting if what we found was removing the center part of the grill allowed air to pass into the engine compartment (at speed) and aid in cooling .

alextaylor29

Overall this has been a very informative thread and thanks for the videos GreaseMonkey! I have no conerns and am keeping my hoodliner and vent removed. I live in a very hot climate (AZ) for me me, this is a no brainer. I run my AC on recycle mode anyway so I'm not worried.

Good stuff there though and everyone kept it pretty civil which is a testment to the MB Owners forum.

Ryououki

I took my liner and plastic piece out yesterday and like the sound from the engine bay.

Did anyone else have major issues with those plastic screws in the plastic piece? After breaking them I had to just drill them out.

E55NOVA

Back from 2012. Anyone else removed the hood liner and plastic piece? Any negative effects? Thanks

E55NOVA

Anyone else?

brdaun

Were the 160+ posts from 2012 not enough of a sell?
For what its worth i have both of those removed. heat definitely dissipates from the plastic vent and the liner allows for a little more blower noise (mainly under cruising conditions)

E42AMG???

E55NOVA

Well, after 6 years I was hoping to see what others have experienced from removing the vent and liner.

E55NOVA

That I knew about. I was just making sure no one was affected by apparent CO poisoning, God forbid.