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I have a 85 with a 6.9 diesel. I am leaking coolant and I can't figure out where and I am looking for suggestions. I see coolant on the passenger side of the engine compartment. I took the heater core off and checked it and it seems fine. I replaced the heater hoses with new ones. There is antifreeze on the housing for the heater core outside but not inside. Coolant is also on the starter, front spring and oil pan and everything in that area. I see no antifreeze on the radiator, fan, or radiator hoses. My motor oil looks black and smells fine. I don't have any smell in the cab or condensation on the windshield. Any ideas please reply thanks.
I looked around the block heater to see if it was leaking and it is all dry and seem so be sealing
Last edited by 85grey; Jan 30, 2011 at 05:59 PM.
Reason: more info
6.9's had a notorious leak at the back of the passenger side heads. Usually caused by the CDR valve not being maintained, sucking oil into the intake, and into the rear two cylinders since they were the closest to the CDR. This caused the bolts to stretch because the extra BTU's created by the burning motor oil in those cylinders. Check your passenger side head, rear end, closest to the firewall. Almost bet you can see where it has made a stream.
Also, these had some kind of a factory recall years ago. There was a small ball-bearing pressed into several places in the cylinder head to block off coolant passages. The factory recalled these to put a bigger ball-bearing in because the original wasn't quite big enough.
No guarantee's, but I'd start there and work it out.
thanks, It doesn't seem to leak when it is not running. I have a piece of cardboard under it so I could see any new leaking after it is cooled off and the cardboard is clean after a day and a half of sitting