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

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 01-24-2018, 07:54 PM
Registered User
 
Join Date: Jul 2003
Location: Ocean Isle Beach, NC
Posts: 2,443
Overheating

Yesterday I was stuck in a slow moving parade out of a parking garage. Was hardly moving for about 45 minutes. Had the car in Drive the whole time with the AC on. After about 25 minutes or so I noticed that my temperature gauge had hit the 120 mark. It wasn't quite to the red line, but it was darn close. I immediately turned on the heat, hoping to get some cool coolant flowing through the system. That seemed to work as the temp slowly came down to about 100. Then on my three hour drive home, the temp dropped to its usual 75 to 80 degree number.

All seemed well, but is there any chance some damage was done and is there anything I should check?

This is my E300D BTW.

__________________


Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - being parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 219,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 19,000 miles
'14 Smart electric cabriolet 13,500 miles
Reply With Quote
  #2  
Old 01-24-2018, 07:56 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Location: Texas Hill Country
Posts: 4,915
Fan clutch and/or thermostat.
__________________
'11 Honda Accord EX - "The Daily" 69K
'83 500SL Euro - "The Money Pit" 116K
'91 350SD - "Diseasel Jr." 173K
'94 BMW 530i Touring - "BMWtf LoLwagen" 233k
Reply With Quote
  #3  
Old 01-24-2018, 08:00 PM
Dubyagee's Avatar
All fields are required
 
Join Date: Jul 2006
Location: SE
Posts: 5,439
Quote:
Originally Posted by Diseasel300 View Post
Fan clutch and/or thermostat.


Yep. A flow problem. Air or coolant. Simple thing would be to rinse out the fins of the radiator of dirt, debris.


Sent from my iPad using Tapatalk Pro
Reply With Quote
  #4  
Old 01-24-2018, 08:12 PM
Registered User
 
Join Date: Jul 2003
Location: Ocean Isle Beach, NC
Posts: 2,443
Wow, quick replies - thanks guys.

Thermostat was replaced seven years and 70K miles ago. Original and replacement are both 80 degree thermostats. Coolant done every three years with GO5 or Mercedes coolant. Have to check the radiator fins, but I would be very surprised if they weren't pretty squeaky clean.

Might not be a bad idea to replace the thermostat. How do I check the fan clutch? This is the first time in the 17 years I've owned the car that I've had an issue like this.

Does the fact that things cooled down and got back to normal after turning on the heat and doing the drive home tell me that anything is definitely good or bad?
__________________


Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - being parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 219,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 19,000 miles
'14 Smart electric cabriolet 13,500 miles
Reply With Quote
  #5  
Old 01-24-2018, 08:20 PM
dkr dkr is offline
Registered User
 
Join Date: Oct 2009
Posts: 563
My new thermostat got flaky after about 40K miles. Unfortunately, with the quality of new parts these days, putting a new part in recently doesn't mean it will stay working.

Dkr.
Reply With Quote
  #6  
Old 01-24-2018, 08:21 PM
Registered User
 
Join Date: Dec 2006
Posts: 3,479
Did the electric aux fan come on?
Reply With Quote
  #7  
Old 01-24-2018, 08:48 PM
Registered User
 
Join Date: Jul 2003
Location: Ocean Isle Beach, NC
Posts: 2,443
Quote:
Originally Posted by Mxfrank View Post
Did the electric aux fan come on?
Have no idea. Is there a way to test it?
__________________


Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - being parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 219,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 19,000 miles
'14 Smart electric cabriolet 13,500 miles
Reply With Quote
  #8  
Old 01-24-2018, 09:00 PM
Registered User
 
Join Date: May 2009
Location: The slums of Beverly Hills
Posts: 6,164
Common problem. The viscous clutch fan can't keep up with the cooling needs of these engines at low speeds. A new viscous clutch won't fix this because the fan is limited by the engine speed.
Reply With Quote
  #9  
Old 01-24-2018, 09:12 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Location: Texas Hill Country
Posts: 4,915
Quote:
Originally Posted by tjts1 View Post
Common problem. The viscous clutch fan can't keep up with the cooling needs of these engines at low speeds. A new viscous clutch won't fix this because the fan is limited by the engine speed.
Sure seems to work for everyone else.
__________________
'11 Honda Accord EX - "The Daily" 69K
'83 500SL Euro - "The Money Pit" 116K
'91 350SD - "Diseasel Jr." 173K
'94 BMW 530i Touring - "BMWtf LoLwagen" 233k
Reply With Quote
  #10  
Old 01-24-2018, 09:18 PM
Registered User
 
Join Date: May 2009
Location: The slums of Beverly Hills
Posts: 6,164
Quote:
Originally Posted by Diseasel300 View Post
Sure seems to work for everyone else.
Yeah it works so great that this question comes up dozens of times every spring on the 124 forums. People replace the viscous clutch and the problem comes up again. Then some genius tells "Oh well you need to replace the radiator", they do that and then they come back again. "Oh well how old is your water pump blah blah blah".

The viscous clutch fan on the inline 6 powered W124s is undersized. Look at the 4 or 5 cylinder W124. These cars use a viscous fan with much wider blades because theres more room for the fan. The inline 6 doesn't leave enough room between the engine and the radiator for a properly sized viscous clutch fan.
http://www.benzworld.org/forums/search.php?searchid=25474937
Reply With Quote
  #11  
Old 01-24-2018, 09:51 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Location: Texas Hill Country
Posts: 4,915
Quote:
Originally Posted by tjts1 View Post
Yeah it works so great that this question comes up dozens of times every spring on the 124 forums. People replace the viscous clutch and the problem comes up again. Then some genius tells "Oh well you need to replace the radiator", they do that and then they come back again. "Oh well how old is your water pump blah blah blah".

The viscous clutch fan on the inline 6 powered W124s is undersized. Look at the 4 or 5 cylinder W124. These cars use a viscous fan with much wider blades because theres more room for the fan. The inline 6 doesn't leave enough room between the engine and the radiator for a properly sized viscous clutch fan.
Mercedes-Benz Forum
That's great, so explain how so many folks have the viscous clutch fans on the 6 cylinders WITHOUT overheating problems?

If the engine cooling system is healthy (and that includes internal cooling passages), the stock cooling system should keep up, especially in the winter time and in cooler climates.

If the OP wasn't having overheating issues previously, use common sense and fix what broke.
__________________
'11 Honda Accord EX - "The Daily" 69K
'83 500SL Euro - "The Money Pit" 116K
'91 350SD - "Diseasel Jr." 173K
'94 BMW 530i Touring - "BMWtf LoLwagen" 233k
Reply With Quote
  #12  
Old 01-24-2018, 10:42 PM
CDTurbo001's Avatar
Registered User
 
Join Date: Oct 2017
Location: Campbellsville, KY
Posts: 190
With those symptoms I'd first check the fan clutch. If the air coming out from around the fan shroud is good and warm but the fan is mostly coasting on the shaft, it's bad. Could also be general crud in the cooling system but seems unlikely with your regular coolant flushes.

That's about the most gentle way to overheat an engine - got warm slow, didn't shut off and heat soak or rapidly cool, and got cooled down gradually and completely. If any damage was done it's only because said component was on the brink anyway.
__________________
'82 300CD
"Pearl", the very first turbo diesel 123 coupe
Totaled 11/23/18, rebuild in progress.
'85 300TD, "Artemis".
'78 300D euro, "Ol' Red", mostly retired.
'85 300D, "Gandalf".
Reply With Quote
  #13  
Old 01-24-2018, 10:48 PM
Registered User
 
Join Date: Mar 2014
Location: Philly
Posts: 449
Easy test for the fan clutch is to see how it behaves when you shut off the engine. have a helper shut off the engine and if the fan comes to a dead stop right away its probably good. If it freewheels to a stop its on its way out and should be replaced. That test and a new clutch solved my higher temp problem.

A new radiator can also be an option. I had to replace mine last year and never put the fan back on. Ran fine from Feb 2017 to today and its still off. Not that I recommend that for anyone, but the new clean and free flowing radiator seems to handle all ranges of ambient temps even with the AC on.

If youre going to replace the fan better get the proper allen tool, i.e. allen bit on a long metal shaft, other wise prepare to fight getting the fan bolt loose and out. There another tool to lock the water pump pulley. Not hard just there aint much room in between the radiator and fan clutch. BTDT on my 87 300TDT recently. Lots if how to's on this one
__________________
Treetops
87 300TD 227K Miles
99 E300 225K Miles
Reply With Quote
  #14  
Old 01-24-2018, 11:01 PM
Registered User
 
Join Date: Dec 2006
Posts: 3,479
The electric fan is triggered by two conditions:

Low speed comes on when the a/c high side pressure exceeds about 300psi.

High speed comes on at between 100-105C depending on the engine. At high speed, there should be more than enough airflow to keep the engine cool regardless of whether the clutch fan is working correctly.

You can jumper around the low pressure switch to see if the fan is functional, but that wouldn't tell you whether the switch was working. Same for the high speed switch.

One thing you should probably do is to check the low speed fan resistor, which is a white ceramic box on the left inner fender. These resistors often fail.
Reply With Quote
  #15  
Old 01-25-2018, 12:25 AM
#TRUMP2020
 
Join Date: Jun 2012
Location: Virginia
Posts: 790
I'm surprised no one has mentioned the fan belt? Your w210 has two aux radiator fans triggered by the A/C. One electrically driven, and a second fan that is driven by the first fan via a small rubber belt. If you lose the belt, you lose the 2nd fan. It's easy to test - with the car off, spin one fan, and the other should spin as well.

__________________
1998 E300 turbodiesel

America's Rights and Freedoms Are Not The Enemy!
Reply With Quote
Reply

Bookmarks

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 10:04 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