'87 300E almost overheating

[anthonyb]

Got an 1987 300E with 172k miles on it. I just wanted to know at what point the auxiliary fan comes on in this particular car - i read on a somewhat related thread that for a 190E it kicks in around 110C, is it the same for the 300E? Around here, the summertime temps get up in the 100-110's (F, not C), and my engine temp routinely gets up to about 110C sitting at idle in traffic - awfully close to that 120 redline. Is this basically normal for this car under these conditions, or is my cooling system not working as it should?

thanks,

anthony

[PThiringer]

My 90 300E temp never really gets much above 100C and it normally runs around 90-95 in the summer, when the car is moving. My mechanic once replaced my thermostat when the car temp was getting up to your levels when idling...

[Michael]

I've got a '88 300TE that almost NEVER hits 100 C. Perhaps your radiator's lost some/much of its capacity to get rid of the heat? Could be it's clogged, at least partially...however, a relatively cheap place to start would be to replace your thermostat; if no help, then I'd suggest you have someone take a look at your radiator, and go from there. Another product that might help is Red Line Water Wetter. This product increases your cooling system's capacity to wick heat away from the metal, so it'll make the hottest parts of your engine run cooler. If you're interested, I'll put you in touch with the manufacturer. Good luck!

[donwo]

My 1987 300e with 60,000 mi ALWAYS runs with the temp gage right between the 80 and 90 degree mark. In summer at idle it will rise to about 100 degrees but will immediately return to the 80 degree mark once I start moving. I would start with the thermostat and maybe change the coolant.

Good luck


------------------
Donwo
1987 300E (60,000 mi)

[This message has been edited by donwo (edited 07-15-1999).]

[MB STARS]

Have you check your engine fan clutch..????
a defect fan clutch will cause high temp in engine idle or clogged radiator too.

------------------
MB STARS Master Guild Technician,12 years MB tech
5 years independent shop owner

[anthonyb]

Thanks for the responses, it'll give me a good place to start. Now that i know that this *isn't* normal, i just hope i don't overheat it before it gets fixed. =)

anthony

[Benzmac]

Do the easy thing first and replace the thermostat!! It is cheap and easy to replace and I have seen a rash of them faulty lately. I'll bet if you rev the engine it'll cool off. Very clear signs of a thermostat problem.

------------------
Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

[anthonyb]

Took the car into the dealer this week and had the thermostat replaced - didn't solve the overheating problem. So now I'm thinking either the fan clutch or clogged cooling system. I know the main fan *runs,* but is there any way to figure out if the fan clutch is good/bad? And would a coolant flush help things out?

thanks again,

anthony

I had the exact same problem with my 87 300E and I replaced the thermostat and nothing happened. The way to tell if your fan clutch is bad is to rev the engine and have someone watch the main fan. It should speed up in relation to the engine speed. If the clutch is bad, it will just barely turn while the engine is doing high RPMs. After changing my thermostat, my tech wanted to see if the aux fan would cut on, so we parked it in the garage with the AC on and let it idle, we even put a sheet over the front of the radiator so as to block off air flow, and we could not get get the temp above 110. the aux fan will not cut on until the temp gauge hits the white line directly below the red line, my aux fan still worked, he connected the wires to make sure it ran. In conclusion, we found that we could not make my car overheat, even though it runs at temps of 95 to 105 regularly, so we decided i just have a 300E that runs warm. It is not harming anything, so oh well. Hope this helps.


------------------
Chris
'87 300E