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 11-29-2006, 09:54 AM
Tubber
 
Join Date: Apr 2006
Location: Whitby
Posts: 37
Trying to track a coolant leak, '84 300D

450,000 km on car, Frybrid SVO kit installed.

Aux. coolant pump wired to come on with ignition.

I've checked all my coolant connections that I installed with the kit and they are all dry. The water pump isn't making any noises. When the car is warmed up and then shut off, the leak is there sometimes and other times not. Some leaks are a few drips, other times I lose as much as 1/2-1 litre of coolant. The car doesn't leak when its running, only when shut off, and the leak stops after a couple of seconds, or as much as 10 minutes.

Trying to find the location of the leak is dufficult. The closest I can nail it down to is from underneath, it drips from the passenger side of the crank area, dripping off the oil pan.

Questions are is it the water pump itself or the gasket? And with the mileage I have, might I just replace the water pump anyways if the gasket is no good? Or is it something else? The water pump housing and associated clamps and connections appear dry. The belt driven fan appears to have blown some coolant around as well.

Oh, and I had the leak before I wired the aux pump to come on with the ignition.

Thanks

Blaine

Reply With Quote
  #2  
Old 11-29-2006, 10:19 AM
rrgrassi's Avatar
mmmmmm Diesel...
 
Join Date: Jun 2006
Location: Royse City Tx
Posts: 5,122
With the engine cold, but after you notice the leak, feel under the water pump. Mine started leaking like that, with the same kind of drip. Turned out to be the water pump.

Also, if you have a hose in hose set up, if there is an internal leak, you may not see it at the fittings. Check your veggie oil for coolant contamination.

Also, since you have the Aux Water Pump wired to run when the ignition is on, I hope you wired in a 1 amp fuse to protect other items ons the same circuit.
__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 133K miles-replaced the other '06 that quit after 300k miles. (did not catch the bad cam in time)

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 195K

90 Dodge D250 5.9 Cummins/5 speed. 400K
Reply With Quote
  #3  
Old 11-29-2006, 12:04 PM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,299
I'm guessing water pump. You might borrow a gizmo that applies pressure to the cooling system. Very handy for finding small leaks. You pump up a few pounds and walk away for a while.
__________________


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
  #4  
Old 11-29-2006, 02:33 PM
speedy82's Avatar
Raccoons killed a Honda
 
Join Date: Jun 2005
Location: Ottawa, Illinois
Posts: 130
Trying to track a coolant leak

water pump. same thing happened to me. It ran down along the oil pan before puddling.
__________________
1980 300SD (Mr. Sparkles), 1976 450SEL, 1982 300D turbo, 1989 VW Cabriolet morphing into a td cabriolet , 1997 TDI Passat, 1996 piece of Jeep,1993 F150, 1990 F250 7.3L...i think that's it, for now.
Reply With Quote
  #5  
Old 11-29-2006, 02:40 PM
Tubber
 
Join Date: Apr 2006
Location: Whitby
Posts: 37
Quote:
Originally Posted by rrgrassi View Post
With the engine cold, but after you notice the leak, feel under the water pump. Mine started leaking like that, with the same kind of drip. Turned out to be the water pump.

Also, if you have a hose in hose set up, if there is an internal leak, you may not see it at the fittings. Check your veggie oil for coolant contamination.

Also, since you have the Aux Water Pump wired to run when the ignition is on, I hope you wired in a 1 amp fuse to protect other items ons the same circuit.
I installed an inline 30 amp fuse for the aux pump, just to be safe. I'm not sure I understand how a leak in the HIH can end up coming out near the area of the water pump. Wouldn't I notice a rough idle and white smoke if coolant was in the VO? The car seems to run better on VO as it is. I can see the general area where the leak is occurring; its not a situation where I'm losing coolant and can't find an external leak source.
I drove it several times today. After a 15 km drive, I parked it in the driveway(slight incline) facing downhill and it leaked at least 1/2 litre steady for 5-7 minutes. I replaced the lost coolant, then drove it the same distance 1 hr later, parked it twice in dry parking lots, and it didn't leak a drop when shut off. Both instances were in town driving.
I guess when the system is hot and under pressure, something is letting the coolant out, I was just wondering if these symtoms I'm having are typical of a failing water pump,or its gasket. The water pump isn't making any funky noises at all. The mileage is higher and perhaps the increase in demand the VO kit has made on the pump, its decided to wave the white flag.
What is this tool called to pressurize your system when its cold and where has anyone borrowed it from? It'd be easier dealing with coolant issues on a cold car rather than a hot one

Thanks for the input

Blaine
Reply With Quote
  #6  
Old 11-29-2006, 07:45 PM
Registered User
 
Join Date: May 2006
Location: W. WI
Posts: 307
I had a mystery leak in a small Ford. I know of a good service wrench that put an ultra violet die in the coolant ... two cracked head bolts in opposite corners! Good news was I intended to change water pump, belts ... that weekend so ... and $1300 later, back on the road. I had tried every trick before the die and no go.
Reply With Quote
  #7  
Old 11-29-2006, 08:13 PM
winchester738's Avatar
1983 300 cd
 
Join Date: Oct 2006
Location: Mid Michigan
Posts: 24
Look at the bottom of the waterpump with a mirror, there is a "weep hole"in the housing that lets the coolant drain out of the pump when the shaft seal goes bad, chances are it will keep getting worse, sometimes they will leak when the pump is turning, othertimes they leak when you shut it off

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 10:45 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2022, 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