Why so much heat? Not an overheating thread - PeachParts Mercedes-Benz Forum

latief · #1 08-07-2010, 06:50 PM

No, my car is not overheating......

But generally speaking, it seems like these cars generate tremendous amounts of heat (especially the m104)....my other car, and other cars i have dealt with don't seem to do so.......is there something about the design that causes this? the engine bay is not cramped - relatively speaking, and there is an abundance of air movement.........

just a thought.....i wonder if the newer v6 engines make so much heat...

any thoughts ?

gschira · #2 08-07-2010, 07:12 PM

Ive often thought the same thing about my '88 300 SE (m103). So much heat under the hood. I've speculated (with not a whole lotta edumacation behind that speculation) that a lot of that heat has to be from my pre cats. When that car is standing still and your face is in the engine bay---well, you know, heat rises... Triple dose from radiators, engine and pre cats. My older car (86 Sable-v6) didn't seem to generate anywhere near the same amount of heat Don't have any experience with newer v-6's..........

tjts1 · #3 08-07-2010, 08:47 PM

There is no heat shield over the exhaust manifold and the ignition timing is extremely consevative on US cars because there is no knock sensor.

lkchris · #4 08-08-2010, 10:25 AM

More heat = better fuel economy.

anziani · #5 08-08-2010, 07:25 PM

We've lived at the Desert (Palm Springs) for about 10 years. In the summer (100-118F) I raise the hood on our cars when we return to the garage, especially the E420. I can't believe how much heat boils off. Hopefully I am saving the wiring if nothing else.
Anziani
'93 300CE 190K
'95 E420 120K

latief · #6 08-08-2010, 07:48 PM

Quote:

Originally Posted by anziani

We've lived at the Desert (Palm Springs) for about 10 years. In the summer (100-118F) I raise the hood on our cars when we return to the garage, especially the E420. I can't believe how much heat boils off. Hopefully I am saving the wiring if nothing else.
Anziani
'93 300CE 190K
'95 E420 120K

Exactly my point! they might be withing 'normal' operating specs, but that does not change the fact that they generate tremendous amounts of heat..i guess it is an emissions and fuel economy thing as the guys are saying....

Ivanerrol · #7 08-08-2010, 08:05 PM

The E240 puts out so much heat, I went to the dealership to query this.
Bonnet got so hot above exhaust you could not touch it.

I was more worried about the ultra thin coating of paint that M.B. now use on their cars and the effect that heat would have on it.

All normal according to the dealership technical service manager - for the reasons above - emissions and economy.

Rahulio1989300E · #8 08-08-2010, 08:18 PM

Quote:

Originally Posted by anziani

We've lived at the Desert (Palm Springs) for about 10 years. In the summer (100-118F) I raise the hood on our cars when we return to the garage, especially the E420. I can't believe how much heat boils off. Hopefully I am saving the wiring if nothing else.
Anziani
'93 300CE 190K
'95 E420 120K

Okay, so I am not the only one that does this.

Rahulio1989300E · #9 08-08-2010, 08:19 PM

I suppose we could combat this by using exhaust wraps and upgrading to higher CFM electric fans?

throne7 · #10 08-09-2010, 01:09 PM

Quote:

Originally Posted by latief

No, my car is not overheating......

But generally speaking, it seems like these cars generate tremendous amounts of heat (especially the m104)....my other car, and other cars i have dealt with don't seem to do so.......is there something about the design that causes this? the engine bay is not cramped - relatively speaking, and there is an abundance of air movement.........

just a thought.....i wonder if the newer v6 engines make so much heat...

any thoughts ?

Wow, I was wondering about this myself, I own a 1987 260E. It is hot under the hood. Sometimes I need to check the level of the transmission fluids, which can only done after the car has run for a while on the road. So I pop the hood open and tried to reach for the transmission dipstick, it's so hot, like I am picking up a hot kettle surface with my bare hand. Now a day I keep a pair of winter gloves (yes thick winter gloves) in the car so that if I need to check the trans fluid I wont' get my hands burned. Enough said.

tjts1 · #11 08-09-2010, 03:40 PM

Quote:

Originally Posted by lkchris

More heat = better fuel economy.

LOL yeah right.

latief · #12 08-09-2010, 03:58 PM

since we are talking heat here, and I am obsessed with it these days due to the weather, what is more effective at withstanding high temps, diesel grade oil, or synthetic oil? I am running Mobile Delvac 15w-40 in my car per manual recommendations...

thoughts

oldsinner111 · #13 08-09-2010, 04:09 PM

I use diesel rated oil in my gasser's.I'm running 5w40 sync. rotella in the s320.15w40 regular rotella in my 300sd.I change the diesel every 4,000 miles,because of carbon.

lkchris · #14 08-10-2010, 11:35 AM

Quote:

Originally Posted by tjts1

LOL yeah right.

You're laughing in ignorance again.

mak · #15 08-10-2010, 12:31 PM

Quote:

Originally Posted by gschira

Ive often thought the same thing about my '88 300 SE (m103). So much heat under the hood. I've speculated (with not a whole lotta edumacation behind that speculation) that a lot of that heat has to be from my pre cats. When that car is standing still and your face is in the engine bay---well, you know, heat rises... Triple dose from radiators, engine and pre cats. My older car (86 Sable-v6) didn't seem to generate anywhere near the same amount of heat Don't have any experience with newer v-6's..........

my 89 300se Euro had tremendous amount of heat soak after shut-down. this would lead to stuttering re- starts for a few seconds. problem resolved by installing a exhaust heat wrap .The under hood temperature has dropped dramatically. Amazing difference in hot starts too.
mak