Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

LinkBack Thread Tools Display Modes
Old 06-09-2003, 04:40 PM
Rick Miley's Avatar
Spark Free
Join Date: Jun 1999
Location: Land O Lakes, FL
Posts: 3,086
June is Cooling System Month

Since everybody else is posting about their cooling system problems, I'll chime in with mine. Becuase of a faulty relay connection, I've had some experience with an inoperative aux fan in the 240D. I've noticed that when the fan isn't working, the coolant temp quickly runs up to 105 at any road speed. When the fan is working, however, the coolant stays right at 90.

I would have expected more ram air coming through that huge upright W123 grill at highway speeds, but apparently it needs help from the electric fan. Does anyone think the cooling system has a problem?

And no, I'm not ready to sell this car yet.
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References
Reply With Quote
Old 06-09-2003, 04:54 PM
The Warden's Avatar
Certified diesel nut
Join Date: Mar 2002
Location: Pacifica (SF Bay Area), CA
Posts: 2,946
On hot days with the a/c on, my water temp will start to rise. I shut the a/c off at 100 to prevent damage, although I'm sure that the cast-iron OM617 can handle it. This is with a non-operational auxiliary fan, and I also believe that my engine fan clutch is dead.

Have you ever heard the engine fan activate? If it's anything like the fan on my truck, the car will all of a sudden start doing its jet engine impression. In addition, the car might feel like it's losing some power, but I'm not sure on that. If you're not getting this, try spinning the fan with the engine not running...if the engine's cold, it should turn but with difficulty.

My guess would be that the engine fan clutch is dead but that the cooling system is otherwise happy. I'm sure it could stand to be flushed out, though...I know that I need to do that with mine.

Hope that helps some...good luck!
2001 VW Jetta TDI, 5 speed, daily driver
1991 Ford F-350, work in progress
1984 Ford F-250 4x4, 6.9l turbo diesel, 5 speed manual
Previous oilburners: 1980 IH Scout, 1984 E-350, 1985 M-B 300D, 1979 M-B 300SD, 1983 M-B 300D
Spark-free since 1999
Reply With Quote
Old 06-09-2003, 06:08 PM
Registered User
Join Date: Sep 2001
Location: central Texas
Posts: 17,277
Well, you are just having one thermal problem after another... bummer given where you live..
"engine fan clutch is dead " I second this probablilty.. and you might as well switch to the 9 bladder while you are in there..
Reminder... the fan clutch is supposed to be stored vertically,,,, and do not set it down on its front side...
If this does not really really help... it might be time to blast the inside of the block and flush...and clean or replace the radiator....and check the opening temp of the thermostat... and make sure you do not have any air bubbles...

But call me if you get really disgusted working on such an old car....
Reply With Quote
Old 06-09-2003, 06:52 PM
Old Deis
Posts: n/a
Two years ago in the sweltering NW heat (I think it got to 80 that week) I began to notice some high temps on the old 78 300D.
The cure was to remove the radiator and spray through the fins with degreasor and then water. Amazing how much stuff was in there. Can't do it in place very well with the AC condensor sitting right behind it.
Reply With Quote
Old 06-09-2003, 08:08 PM
The Least of These
Join Date: Jun 2002
Location: Exton, PA
Posts: 559
One of the two aux fans on my 124 went this time last year. When I removed the fan for replacement, I noticed a ton of road junk caught between the fan motor and the AC condensor essentially restricting any airflow to the vents of the motor. I believe that this ultimately caused the failure.

Perhaps periodic cleaning of this vital area could save someone $131 and a few knuckle scrapes.
1996 (W210) E300D 86K - Traded in for a Lexus
1992 (W124) 300D 2.5 Turbo 202K - Sold
1983 (W123) 300D, 146K - Sold
1970 280S, 263K - Sold - Beginning of addiction
Reply With Quote
Old 06-09-2003, 08:59 PM
engatwork's Avatar
Join Date: May 2000
Location: Soperton, Ga. USA
Posts: 12,202
I took my 240D up to Jackson on Sunday to take a look at an old 180. On the interstate, at 80 with the a/c on max and going up hills it would go to 100 dC or just slightly above. Shutting the air off and running heat on hi would drop it immediately. I am putting a new radiator and water pump in it over thne next day or so and will let ya'll know if that makes any difference. I did notice that the impeller on the water pump is slightly smaller than the new one. The 300D gets to 90 dC and stays there under the same conditions. I'll keep ya'll posted.
Reply With Quote
Old 06-10-2003, 10:56 AM
Rick Miley's Avatar
Spark Free
Join Date: Jun 1999
Location: Land O Lakes, FL
Posts: 3,086
No fan clutch on this baby.

It's got a solid metal hub. Greg, does yours have a clutch? I'm thinking that might be a nice addition, so the fan doesn't draw engine power when not needed. Imagine that - having some extra power on tap in a 240D! OTOH, this being sunny Florida, the clutch would be engaged most of the time anyway.

I'm not in fear of the engine overheating, now that the electric fan is working. And I have plans to change the coolant and clean the exterior of the radiator while I'm there. I was just hoping for some comment on the apparent lack of ram air effect.
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 04:04 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page