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 ShopForum > Technical Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #16  
Old 07-16-2010, 05:09 PM
Registered User
 
Join Date: Jul 2003
Location: Bellevue WA
Posts: 167
When you replaced the standard fan and fan clutch

with electric fan/s, what did you do re the aux fan switch in the top front of the engine? The aux fan is in front of the radiator. Aside from its use with AC, it is my understanding that it also comes on when heat rises from load conditions. You may have replaced its functions with another electric fan, but the aux fan really reduces the temp when it comes on going up hills. And, if your new fan relies on that switch to turn on, you could have a bad switch which is very common. Also your definition of normal temp may be quite low. I have read that anything below ~110 is OK-but only under load.
__________________
87 300D 265Kmi
Factory rebuilt crate 603.96x engine at 200K
Reply With Quote
  #17  
Old 07-17-2010, 12:44 AM
CANDIDE's Avatar
300SDL 265K
 
Join Date: Aug 2008
Location: Placerville,CA
Posts: 167
Quote:
Originally Posted by eltito View Post
Lol - awesome. I'll keep my eyes open.

Reason I ask is that I passed a guy in a black 300SDL going up Bass Lake grade a few weeks back, then saw him later on Pleasant Valley Rd. Stood out because it's exactly the same color scheme as my car - even had the same wheels!

If your ever out and about in P*Ville and you see a tall bald guy in a black & silver 87 SDL with a Biodiesel emblem on the trunk, feel free to say hello.

Incidentally, I'm having the exact same overheating issues you are. Just ordered a new Behr radiator and I'm hoping that takes care of it. Only things that won't be new after that is the water pump, monovalve and temp gauge.

I'm also missing the noise panels that are supposed to be under the engine. No idea how that affects cooling.

Could altitude have anything to do with it? We're not that high up, I don't see why it would.
We are at about 3000', yes the air is a tad thinner, but I don't think it matters. It increases the boiling point of water a few degrees.

I haven't seen many sdl up here, if I see yours I'll give a hello.
Reply With Quote
  #18  
Old 07-17-2010, 12:54 AM
CANDIDE's Avatar
300SDL 265K
 
Join Date: Aug 2008
Location: Placerville,CA
Posts: 167
Quote:
Originally Posted by theref View Post
with electric fan/s, what did you do re the aux fan switch in the top front of the engine? The aux fan is in front of the radiator. Aside from its use with AC, it is my understanding that it also comes on when heat rises from load conditions. You may have replaced its functions with another electric fan, but the aux fan really reduces the temp when it comes on going up hills. And, if your new fan relies on that switch to turn on, you could have a bad switch which is very common. Also your definition of normal temp may be quite low. I have read that anything below ~110 is OK-but only under load.
I've got a 16" fan and a 10" in a steel shroud that is 1/2" above the radiator. They both kick on at 80C. My controller uses the MBZ temp sensor for its reference. The temp I read on my gauge matches my IR gun within a few degrees.
It seems worse since I installed the new radiator and thermostat, but, the ambient temperature has risen lately. Last few days its been 90-100F. AC sure works good...too bad it exacerbates the temp issue
Anyhow, once I get my home projects under controll and the stock market takes the dive, I'm betting on, I'll have the time and a few extra bucks to devote to Whitey.

After reading the troubleshooting guide, I'll investigate the air flow through the radiator. Although, at freeway speeds the fans are not the main source of cooling.
Reply With Quote
  #19  
Old 07-17-2010, 09:04 AM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by CANDIDE View Post
I have 2 electric fans and a custom shroud instead of stock fan.
Plenty of hot air being emitted from fans.




But, obviously I'm missing something.


You've clearly replaced every single component in that system and, at this point, it should be operating perfectly.........with one glaring exception.

When you change the airflow characteristics via the use of different fans/shrouding........etc, the result must be considered an experiment. You claim that "plenty of hot air is being emitted by the fans", however the engine might beg to differ with you.

Airflow across the radiator is a complicated subject at higher speeds and the fans may impede this airflow rather than enhance it.

I'd change back to the stock setup and see if your issue disappears.
Reply With Quote
  #20  
Old 07-17-2010, 12:31 PM
CANDIDE's Avatar
300SDL 265K
 
Join Date: Aug 2008
Location: Placerville,CA
Posts: 167
Quote:
Originally Posted by Brian Carlton View Post
You've clearly replaced every single component in that system and, at this point, it should be operating perfectly.........with one glaring exception.

When you change the airflow characteristics via the use of different fans/shrouding........etc, the result must be considered an experiment. You claim that "plenty of hot air is being emitted by the fans", however the engine might beg to differ with you.

Airflow across the radiator is a complicated subject at higher speeds and the fans may impede this airflow rather than enhance it.

I'd change back to the stock setup and see if your issue disappears.
Yes, that makes perfect sense.
Reply With Quote
  #21  
Old 07-27-2010, 01:13 AM
CANDIDE's Avatar
300SDL 265K
 
Join Date: Aug 2008
Location: Placerville,CA
Posts: 167
Quote:
Originally Posted by Brian Carlton View Post
You've clearly replaced every single component in that system and, at this point, it should be operating perfectly.........with one glaring exception.

When you change the airflow characteristics via the use of different fans/shrouding........etc, the result must be considered an experiment. You claim that "plenty of hot air is being emitted by the fans", however the engine might beg to differ with you.

Airflow across the radiator is a complicated subject at higher speeds and the fans may impede this airflow rather than enhance it.

I'd change back to the stock setup and see if your issue disappears.
I installed the original mechanical fan. The overheating is worse. And the engine feels more sluggish under acceleration. So, I went back to my electric fans. Also, today I removed the new MBZ thermostat and put my original MBZ thermostat back in. It runs cooler. About 10-15 degrees C cooler. Both thermostats have identical P/Ns and were bought from the same MBZ EDH dealership.

And now I measure 30-40 degrees F difference between upper and lower radiadtor hose.

I am happy with the reduction in operating temperature, I am, however, flummoxed by the difference by changing 2 identical part number thermostats. I have other projects that compel me, so I can't delve into a more definite description of my overheating problem.
Reply With Quote
  #22  
Old 07-27-2010, 05:26 PM
Registered User
 
Join Date: Oct 2005
Location: Austin TX
Posts: 352
I ended up replacing my fan clutch and drilling a hole in my therm and all is nice and cool. Just a hair over 80C .
__________________
Professional greasecar installer
Austin TX


98 Jetta TDI with grease car kit + veg-therm (totaled)
87 MB 300SDL running on B99 / greasecar kit + 30 fphe
www.austingreaseguys.com
Reply With Quote
  #23  
Old 07-27-2010, 06:26 PM
CANDIDE's Avatar
300SDL 265K
 
Join Date: Aug 2008
Location: Placerville,CA
Posts: 167
Quote:
Originally Posted by latitude500 View Post
I ended up replacing my fan clutch and drilling a hole in my therm and all is nice and cool. Just a hair over 80C .

Fan clutch tests good.
What size hole did you drill in the thermostat?
Reply With Quote
  #24  
Old 07-29-2010, 11:20 PM
Banned
 
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Quote:
Originally Posted by CANDIDE View Post

I am happy with the reduction in operating temperature, I am, however, flummoxed by the difference by changing 2 identical part number thermostats. I have other projects that compel me, so I can't delve into a more definite description of my overheating problem.

Clearly, M/B quality control is not what it should be............
Reply With Quote
  #25  
Old 08-11-2010, 07:08 PM
CANDIDE's Avatar
300SDL 265K
 
Join Date: Aug 2008
Location: Placerville,CA
Posts: 167
Update

When I went back to my original thermostat, the overall engine temps did drop, I still was still unable to use the ac going up Bass Lake grade on highway 50. If ac on then engine temp would hit 110C, with it off, about 95-100C.

Today I modified my spare thermostat by cutting the springs out, heating it until it was opened 1/2 inch, then soldering the main brass shaft and the diverter in place. It fixes it open all the time and retains the diverter.

It was cool today at 80F, I drove up Bass Lake grade with ac on at 65-70mph and the temp hit 95C max. I am a happy camper. I know that I'll have to change back the original thermostat in November, but its a small price for the engine temp reduction.

Before, when I re-installed the old thermostat, and today when I installed the modified thermostat, I had to drain coolant. When I poured the coolant back in, I poured it into the upper radiator hose untill it started to dribble out of the radiator top hose nipple, the rest of the coolant was poured into the tank. This method seems to get more air out of the head. Later I parked the car on a hill to add coolant to the hose and found I could not add any, usually I could add coolant a couple of times before it was full. This may have been what dropped my engine temps when I re-installed the original thermostat, unable to say for sure.
Attached Thumbnails
300SDL overheats-thermostat1.jpg   300SDL overheats-thermostat2.jpg  
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 07:26 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page