856 blowing water out radiator yet. help!!!!

I've never been into that particlular engine, but the symptoms almost sound like an upsidedown thermostat. Don't know if that is possible on yours, tho.

Have you put a straight-edge on that block? It's about gotta be downstairs after 4 trips thru the head area.

Allan

Does it blow the water out immediately after cranking or after it warms up a bit? Try putting a radiator pressure tester on it without pumping it up, crank it up and see how much pressure it builds up and how fast. What does the temp gauge say while its doing all this?

Stupid thing to say I suppose but it's obvious you have a leak into one of the combustion chambers. The reason I asked about how soon it pushed the water out, I see a lot of cases where there is an air pocket in the coolant that heats rather quickly, causing a loss of coolant soon after it cranks. My suggestion (and you may have already tried it) is to open something near the top of the engine just below the thermostat (a hose or plug, maybe the sending unit itself) to make sure the head especially is full of water with no air pockets. I would also get it full of water and pressurize it and let it sit for a day or two (if it will hold presuure) and see where the water goes. If there's a leak, it will show up somewhere. Don't overlook head bolt holes and such. I've seen the bottoms of them knocked out by having oil or coolant in the holes before tightening them and causing a leak into the water jacket. If it's that bad, should be able to find.

Hope this helps!

Yes and I have used it on something I wanted to get rid of. It will work but I still think, as difficult as it is, you should be able to locate the leak. Drugstores used to sell it around here but I'm not sure now. I think the technical name for it is sodium silicate solution. Is this engine turbocharged and does it have any kind of water/air intercooler or aftercooler? There are test kits available that will tell you if the coolant has any combustion by-products in it. If you get a negative on that, you may be getting air from another source. Kinda' strange its not overheating if its a leak into a combustion chamber or cylinder. Another way I have checked some engines is to take the glow plugs or injectors out of each cylinder and re-install them one at a time (only one), put the pressure gauge on it, and crank it over. The faulty cylinder should show up on the gauge when you put the glow plug or injector back in.

Keep hoping this helps!!!!!

Tommy