m116 Overheating Questions
 

Hey everyone,

I've got my 420SEL here and the other day it was having some temperature issues.

At Idle w/ AC On, sitting for a while in a driveway it crept up to around 110C. The aux fan works.

Around town w/ac (about 35-40mph) it was around 90-100C

On freeway it was around 85C with ac on.

Not really sure about w/o AC. Haven't checked it yet.

My mechanic said that the fan wasn't moving as much air as it normally should. So maybe clutch?

Others have suggested the radiator.

Right now, I'm gonna replace the cap on the bottle (which is a COMPLETE pain to remove as it is right now) and the thermostat.

I'm not sure how old the radiator is, its made by "IMI Radiators." I've never heard of them, but it has a MB emblem on it and some codes. It LOOKS ok and the fins look clear of debris...

Anyone have any thoughts on the whole thing or the radiator. I was hoping someone knew more about the radiator...

http://imgur.com/ykGFol.jpg

http://imgur.com/SVtDGl.jpg


If the cap/tstat don't make a difference..what should my next step be? Replace rad? Replace clutch? $288 (Behr rad) vs $150 (Behr) clutch?
[img]

If the issue was overheating on the road, then the radiator would be to BLAME!

Since the problem is at idle, air flow is the problem.

Fan clutch is the most likely cause. OR debris between condensor & radiator.

ditto.

I believe you guys might be right.

I drove it today, 80 on the freeway, 80 around town for the most part. Got to 100+ in the drivethru with a/c on. Got cooler the more we drove at speed.

I've heard bad things about some clutches any recommended brands?

Most of what I've seen are Behr, $150, Uro for $150, Meyle for $288
Auto Haus lists a Fichtel-Sachs (OES) but it has a 2100005043 part number which I can't seem to find in the EPC and they want $270 for it.

Fan clutch replaced...problem still exists. replacing t-stat and flushing system seeing if that does anything.

RANT: WHAT GERMAN MASOCHIST DESIGNED THIS THERMOSTAT HOUSING?! WHY IS THE THIRD BOLT BURIED BEHIND!? WHO PUT THIS ALTERNATOR BRACKET HERE?! WHY IS IT SO LARGE!? UGH, THIS IS MILES MORE PAINFUL THAN m103/om617! I WANT TO REMOVE THIS ALTERNATOR BRACKET ROAR /end rant.

Ahem.

This was after sitting in the driveway for around 20 minutes with a/c on after some spirited driving...
http://imgur.com/rnYIHl.jpg

What came out of the radiator:
http://imgur.com/WqwFal.jpg

Performed a flush, changed t-stat (PITA)....

that temp looks normal, so it is fixed now?

why is the coolant so red?

temp is not normal. normal is around 80C. That temp was sitting in my driveway and it was climbing upwards, and it was only around 80 outside, the outside temp sensor on the car was under the influence...

Not sure why coolant looks red. it came out golden colored. Probably just camera/bucket.

Going to order new radiator as per recommendation of Hit Man X.

Well make sure there is no crap stuck between the aux fans and the condenser too, you will be surprised what builds up after 10 years... let alone 20.

New rad is partially installed. Some dumb **** killed the threads when they installed the tranny cooler lines to the old radiator...so they wont go on the new one...and i cracked the fan shroud in half.

Replacements will be here tomorrow, then refill, and will be done..hopefully

Also gotta figure out why it was dead this morning...It hasn't been driven in a few days but thats no excuse. My guess is battery issues as its old and the incorrect size...

100 is normal especially with the A/C on. Even talks about that in the owners manual. 120 is overheating. If 110 was an issue red would be at that mark. Remeber these cars are made for speed, idle doesnt do as well as movement. Age is a factor but 100 is normal with A/C on. Compressor steals power causes load and uses power and creates its own heat and moves heat that transfers to the block.

If you do a search here and benzworld.org youll see alot more of it. Since its warmer out the temps just get higher on the gages. Its gonna happen.

If you want it to read lower try cool harness which tricks the Aux fans to come on sooner to keep it cooler.

Problem solved. New radiator. Idled for atleast 20 minutes with full AC on.

http://imgur.com/OCcWKl.jpg

http://imgur.com/3BEDkl.jpg

Nice going. Another happy ending. I love it when guys try to tell you what's normal, when you've lived with a car for 10 or 20 years and know very well it's not normal.

Exactly, my 560 has never been that hot at idle in traffic here in Texas...

A new radiator makes a world of difference on these cars.