Well I smelled a whiff of coolant the other day and managed to find a very small drip of coolant coming from an area "Above" what looks like it should be the water pump... (The water pump looks very small if that is what it is)... Anyway I have a 1985 300SD with the 617OM. I'll try to post a picture or two here so you could see what I mean, it looks clearly like it is seeping from around a bolt, not the weeping holes typically associated with water pump failures..

This would be my first time opening up one of these fine motors, so I want to be sure before I pay the big bucks for the parts!!

Comments?

Steve

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1981 300SD, 174000Miles
1982 300SD, 247000KM
1985 300SD, 318000KM and counting

Steve

Snug up your bolts a bit before trying anything more radical. It does look like it's leaking around the bolt or gasket.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

It's odd that it's leaking around the bolt head. Maybe the water pump housing is cracked. You might try wiping the area down and tighten that bolt up just a bit and see what happens. Run the engine a bit and see what happens. You can also pressurize the coolant system with some compressed air to see if that is were the leak actually is.
It's definetly not the water pump. If it were toast you'd see coolant coming out the weep holes.

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I thought it was very odd myself, safe to maybe take the bolt right out and clean it up a bit I suppose? I would balk at a crack, but stranger things could have happened that is for sure.. Is it true that the water pump is that small? It seems odd on such a hard working engine..

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1981 300SD, 174000Miles
1982 300SD, 247000KM
1985 300SD, 318000KM and counting

Steve

I'm guessing it's pretty cold at your location at the moment. Odd coolant leaks can occur at those temperatures.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

You think "let it fly" until it becomes a more significant leak then? Notice I'm not arguing about the temperatures up here right now..

I want to stay on top of the engine issues here, I know my 617 only has about 30k on the MB rebuild after grandma blew it up with no oil.. it's just a baby...

Cheers to block heaters by the way!

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1981 300SD, 174000Miles
1982 300SD, 247000KM
1985 300SD, 318000KM and counting

Steve

I just replaced my water pump on my 603 and the best deal was at the stealership, a MB rebuilt pump for 78 bucks, with a warranty.

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

I'd at least wipe it down and keep and eye on the coolant level. If it's a small leak it won't cause a problem, but it will get worse eventually.

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