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 12-19-2005, 02:41 PM
Biodiesel300TD's Avatar
|3iodiesel300T|)
 
Join Date: Dec 2004
Location: Albany, OR
Posts: 4,845
Do I have to drain the coolant to change the thermostat

I was just reading up on how to change the thermostat on good ol' DieselGiant's page. Is it necessary to drain all the coolant to change the thermostat? I just had my coolant changed when I got my blockheater installed last month. Is coolant going to spew everywhere if I open the t-stat housing without draining the coolant?

Thanks again.
Andrew

__________________
Andrew
'04 Jetta TDI Wagon
'82 300TD ~ Winnie ~ Sold
'77 300D ~ Sold

Last edited by Biodiesel300TD; 12-19-2005 at 07:43 PM.
Reply With Quote
  #2  
Old 12-19-2005, 02:43 PM
Big J's Avatar
Registered User
 
Join Date: Mar 2005
Location: Roswell, GA
Posts: 152
I just changed my thermostat this past weekend and I lost about 3/4 gal of coolant. I guess you could use a catch pan . . . .
__________________
1981 240D, Auto Trans, 160k miles -- CRASHED!
Reply With Quote
  #3  
Old 12-19-2005, 02:44 PM
Zerohour3k's Avatar
Diesel Enthusiast
 
Join Date: Sep 2005
Location: Ocean County, NJ
Posts: 367
Quote:
Originally Posted by Biodiesel300TD
I was just reading up on how to change the thermostat on good ol' DieseGiant's page. Is it necessary to drain all the coolant to change the thermostat? I just had my coolant changed when I got my blockheater installed last month. Is coolant going to spew everywhere if I open the t-stat housing without draining the coolant?

Thanks again.
Andrew

So long as the engine isn't hot, it won't really "spew" everywhere. I changed mine in the rain, last Wednesday. About a gallon of coolant will leak out, if you don't drain it.. so be sure to have some extra to top it off with. It's a really easy job.. just be SURE not to do it with a hot engine, or the fluid will obviously scald you badly.
Reply With Quote
  #4  
Old 12-19-2005, 02:53 PM
Zerohour3k's Avatar
Diesel Enthusiast
 
Join Date: Sep 2005
Location: Ocean County, NJ
Posts: 367
Here's a question, though. I replaced mine, and didn't notice any "arrow" on my aftermarket T-stat. In fact, Im not 100% sure which direction I put the thing in, at. I know the 'stat is orientated properly, just not sure if it's "facing" the correct rotation. Does this really matter? The car is running at peak performance, 82-90C.. so I'm guessing I have it right anyway.

Does that arrow really mean anything? If so.. did I just get lucky?
Reply With Quote
  #5  
Old 12-19-2005, 03:17 PM
Registered User
 
Join Date: Dec 2002
Location: RI shore
Posts: 2,937
Quote:
Originally Posted by Biodiesel300TD
I was just reading up on how to change the thermostat on good ol' DieseGiant's page. Is it necessary to drain all the coolant to change the thermostat? I just had my coolant changed when I got my blockheater installed last month. Is coolant going to spew everywhere if I open the t-stat housing without draining the coolant?

Thanks again.
Andrew
partially. You can open the radiator drain and empty 2 or 3 liters until fluid level is below top of upper radiator hose (which you are loosening the clamp from anyway. Drain until this connection sucks air rather than leaks fluid.

Now, I just had a thought: what if you reached into the t-stat casting with something like a brake adjuster - something that you could push against the t-stat spring (who cares if you hurt it - you are replacing it) and let loose the several more liters that typically flood out. If I had thought of this the other day, I would have tried it and collected the fluid.
__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.
Reply With Quote
  #6  
Old 12-19-2005, 03:22 PM
Registered User
 
Join Date: Nov 2005
Location: Iowa City, IA
Posts: 1,647
Careful with drain Plug!! Try

I drained miy coolant down past the thermo housing to my best guess. The head of a plastic drainplug to the radiator which takes a large flat blade broke almost as soon as screw driver touched it. Lucky I could still get pliers on it. It reminded me of some VW plastic parts that crumble in the fingers.
Reply With Quote
  #7  
Old 12-19-2005, 03:34 PM
Registered User
 
Join Date: Dec 2002
Location: RI shore
Posts: 2,937
Quote:
Originally Posted by biopete
I drained miy coolant down past the thermo housing to my best guess. The head of a plastic drainplug to the radiator which takes a large flat blade broke almost as soon as screw driver touched it. Lucky I could still get pliers on it. It reminded me of some VW plastic parts that crumble in the fingers.
Don't use a screwdriver, use a washer or a coin. Then you'll naturally apply the 1-2 Nm torque desired. - I'm not that smart to think of that, I just read that recently in the FSM.
__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.
Reply With Quote
  #8  
Old 12-19-2005, 04:18 PM
meltedpanda's Avatar
Certified Benzaholic
 
Join Date: Mar 2003
Location: Central Ky
Posts: 6,265
Quote:
Originally Posted by Zerohour3k
Here's a question, though. I replaced mine, and didn't notice any "arrow" on my aftermarket T-stat. In fact, Im not 100% sure which direction I put the thing in, at. I know the 'stat is orientated properly, just not sure if it's "facing" the correct rotation. Does this really matter? The car is running at peak performance, 82-90C.. so I'm guessing I have it right anyway.

Does that arrow really mean anything? If so.. did I just get lucky?
Yes it does and yes you did . I understand the arrow posistions thermostat for r proper air bleed
__________________
Ron
2015 Porsche Cayman - Elizabeth
2011 Porsche Cayman - Bond,James Bond
Sadly MERCEDESLESS - ALways LOOKING !
99 E320 THE Queen Mary - SOLD
62 220b - Dolly - Finally my Finny! Sadly SOLD
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
19 BMW X5 - Heaven on Wheels
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
Reply With Quote
  #9  
Old 12-19-2005, 04:45 PM
Registered User
 
Join Date: Nov 2005
Location: Iowa City, IA
Posts: 1,647
Quote:
Originally Posted by Pete Burton
Don't use a screwdriver, use a washer or a coin. Then you'll naturally apply the 1-2 Nm torque desired. - I'm not that smart to think of that, I just read that recently in the FSM.
Thanks for tip. Who would a thunk a drain plug with 1 Nm torque? Good lesson learned about plastic fasteners.
Reply With Quote
  #10  
Old 12-19-2005, 07:37 PM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,299
"Does that arrow really mean anything?"

Yes, I thought so....but the last T-stat I bought didn't have one. I examined it very carefully as they were hard to see anyway, no arrow. So No, maybe it doesn't or never did matter. Depending on your T stat housing the arrow pointed ahead or up. Anybody seen an arrow lately??
__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote
  #11  
Old 12-20-2005, 08:48 AM
Registered User
 
Join Date: Dec 2002
Location: RI shore
Posts: 2,937
Quote:
Originally Posted by Stevo
"Does that arrow really mean anything?"

Yes, I thought so....but the last T-stat I bought didn't have one. I examined it very carefully as they were hard to see anyway, no arrow. So No, maybe it doesn't or never did matter. Depending on your T stat housing the arrow pointed ahead or up. Anybody seen an arrow lately??
I just put in a new Behr thermostat last week. The arrow was hard to miss.
__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.
Reply With Quote
  #12  
Old 12-20-2005, 11:23 AM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,299
"I just put in a new Behr thermostat last week. The arrow was hard to miss."

I have a brand new "Wahler" (OEM yes) here and no arrow, I'm pretty sure they used to have one.
guess I'll get "Behr" next time.
__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote
  #13  
Old 12-20-2005, 12:17 PM
Registered User
 
Join Date: Dec 2002
Location: RI shore
Posts: 2,937
Quote:
Originally Posted by Stevo
"I just put in a new Behr thermostat last week. The arrow was hard to miss."

I have a brand new "Wahler" (OEM yes) here and no arrow, I'm pretty sure they used to have one.
guess I'll get "Behr" next time.
you're correct. The Wahler I replaced had an arrow too. Whatever bean counter decided to omit the arrow stamp should be chained to a car and required to remove and install that thermostat 360 times, reoriented in 1 degree increments each time.
__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.
Reply With Quote
  #14  
Old 12-20-2005, 02:26 PM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,299
"chained to a car and required to remove and install that thermostat 360 times, reoriented in 1 degree increments each time"

LOL... Roger that

The last arrowless Wahler I installed was rotated to match the writing on the cross bar of the old one (a Wahler with arrow).
__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote
  #15  
Old 12-20-2005, 07:29 PM
Diesel Giant's Avatar
Registered User
 
Join Date: Oct 2004
Location: Loganville/Atlanta
Posts: 2,156
Just do this

http://dieselgiant.com/thermostatreplacementandmodif.htm

__________________
1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair
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 01:42 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page