Hello members!

Car: 1987 300 DT

I have this weird problem. I dont think my car likes the antifreeze fluid at all. I have been having this issue where it will drain the complete reservoir tank every time i turn the car off. The tank cap had been changed about 2 years ago, and the thermostat has been replaced about 2 years ago also. Any ideas what is causing this flushing of the fluid?

Thanks!

Cracked head,gasket,waterpump,stuck thermostat.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

the antifreeze is pouring from the bottom of the car, does that relate to some of the stuff you described?

This weird problem you describe has a very esoteric scientific name. It is called "A Leak." Something has got a hole in it or has failed. If the leak is external and as bad as you describe it should be easy to find. It could be a cracked or punctured hose, a hole in the radiator, a crack in one of the radiator tanks or fittings, a bad water pump, or (less likely) a failed head gasket. Most of these are relatively easy and relatively inexpensive to repair. Relative to a cracked head or bad head gasket, that is. I have probably missed a few possibilities. With the way my luck has been running lately, I've probably missed your problem completely. I'm sure someone else will chime in here.

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1987 W201 190D

If your car still has its belly pans, the fluid may be running out of the failure point, flowing along the pan to a low point and draining at that point. So don't assume the point of failure is immediately above where the fluid is trickling down.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

It sounds like excessive cooling system pressure is blowing it out through the overflow reservoir. This is a symptom of either a cracked head, or a head gasket that has an internal leak. I have the same issue on my car (87 300D). I'm getting things ready to do the big job myself. Fingers crossed for the gasket. A new head is gonna hurt my a$$.

Could be... hopefully not. In my experience, the pressure in the system will eject some coolant mostly while the car is being driven. Once it's parked and shut down, the coolant usually then enters the cylinders making it hard to start the car again, or especially with a diesel, possibly bending the rods due to hydraulic lock. Still, it could be what you say especially if the belly pan is catching the coolant and letting it drain out when the car is parked.

I replaced the head (and gasket, of course) on my '87 190D recently, so I feel your pain. Make sure you have a good machine shop pressure test the head. Mine had no visible cracks (and I'm pretty good at looking and finding). It turned out it was cracked behind one or two of the valve seats. I posted some pics on this on another thread a while back. Fortunately I got a good used head from another member here very reasonably. Unfortunately it is one of the very earliest castings, so I fear that I do not have a very long term solution.

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1987 W201 190D

Hmm.. I see. Well when i took it to the dealer, the mechanic said he thought it was the water pump so i had a new waterpump sitting in my garage, i am fixing it as we speak. Dam thing takes forever to come out.

I hope the mechanic was right =/

I am also changing the belt tensioner, and the thermostat.

Does anyone have a diagram of the thermostat in the 87 300DT, OM 603?

Thanks!

Diagram showing what? I haven't figured out how to remove the thermostat without removing the 50*C switch just ahead of it. I don't remember if it takes a 22mm or 24mm wrench. There's a notch in the thermostat that corresponds to a tab in the radiator hose fitting so it only goes in one way.

[edit] Oops, too quick on the draw. I suppose the thermostat can be installed with the wrong end into the water pump housing. I have neither an image nor an old thermostat handy to advise you which end goes towards the water pump housing.

Sixto
87 300D

You sure there's a T back on that trunk lid?

Do you see this fluid being blown/forced out of the reservoir or is it just empty after a period of time? They are known to crack.

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Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

the dealer sticker says that the build of the car is a 1987 300 DT.


so unless the dealer lied.. yes it sure is a 300 DT


Its not blowing out of the reservoir tank, it is dripping from the bottom of the car somewhere. the under paneling of the car is removed, so all my tranny oil drips and this radiator fluid leaks are very visible. I assembled the pieces back this weekend after i changed the water pump and the thermostat. The thermostat housing was not closing completely i could only close 1 bolt, because the other bold had cracked inside, so i took the car to a shop and they are going to attempt to remove that broken bolt inside the housing. Hopefully that will stop the leak, because it was leaking from that housing.

Ah..the dealer...did he/she look for "The Trunk Badge Of Truth"?

Hope the leak is fixed, did you ever get a good visual of where it was coming from? The thermostat housing? Or was it leaking from the water pump as well?

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On some nights I still believe that a car with the fuel gauge on empty can run about fifty more miles if you have the right music very loud on the radio. - HST

1983 300SD - 305000
1984 Toyota Landcruiser - 190000
1994 GMC Jimmy - 203000

https://media.giphy.com/media/X3nnss8PAj5aU/giphy.gif

That'd be a first, wouldn't it

Sixto
87 300D

300DT is the 300D turbo. confusing, as there is also a 300TD which is the wagon version of same car.

running with zero coolant is egregious in any vehicle, but especially in an OM603. Get er fixed. asap.

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Paul
Benz-less
I need an SDL !

I will keep you guys posted.

The water pump was bad, it was very loose,


but yes it was leaking from my thermostat housing..

That thermostat is such a pain to change.. WOW! aAHH


Anyone know how i can adjust the idol on the car? my idol is pretty low, its at ~700rpm