Allis D15 engine problrm?

[tomstractorsandtoys]

I have a series II D15 gas Allis Chalmers that I bought two years ago because both my grandfathers had one as well as my Dad. I used it last summer a few hours on a side mounted mower to trim field edges. Last fall the antifreeze was weak so I drained it. A week ago I added new antifreeze and ran it for a half hour or more. Today i used it to move the soybean planter to the shop and it started making a hammering sound in the engine. It is has the correct amount of oil in it and the oil pressure is way over in the normal. The sound seems to be coming from the top of the engine. I also noticed a little antifreeze coming out the overflow tube. When the radiator cap was loosened I got lots of antifreeze as it had a fair amount of pressure in it. The antifreeze was cold as I had been running it about 10 minutes.Temperature guage had not moved yet but maybe it does not work? The block was not extra hot. What do you think happened? Where should I start? Thanks Tom

 

[Janicholson]

Use a bore scope or fiberoptic and look in each cylinder for a piece of carbon or a small screw stuck to the top of a piston. Either one might be made to move and be removed. (let us all hope) Jim

 

[Steve@Advance]

Did the idle/power seem any different?

Might take the valve cover off, look for a broken valve spring, bent pushrod, stuck valve.

The coolant may have been coming out because it was over full. It needs some expansion room.

 

[Bob Bancroft]

AC kept punching and pushing that little engine until, with that last 160 cu in version, they claimed as much or more HP as the old low compression, slow turning 226 in the WD45. Well maybe, but at a cost. That 160 is the only engine I recall having a pre-ignition/knocking problem. If the timing and/or fuel wasn't just right, that knocking would lead to problems. I don't want to be an alarmist. And certainly some time spent checking peripherals is wise. But don't be surprised if you end up pulling the head. Hopefully cleaned surfaces, a new gasket, and maybe some new, better capscrews with a little extra torque is all that is needed. It is easy to work on.

I have a D15II with an AC side mounted mower which is my edge/ditch trimming machine. No engine problems, but it does pop out of third.

I still recall when my cousin [20 years my senior] bought a brand new D15II. What a sweet little tractor. He worked it hard for several years. After he traded it off the casual use home owner had problems with it. The knocking had chiseled a little groove right at the head gasket surface between a couple of cylinders!