Have an issue with my 1978 Ford tractor. Engine is a 4 cylinder diesel. Had a radiator leak bad enough that I swapped the radiator out for a new one. Installed it after feeling my way through the removal and reinstall with the help of Youtube. I am not a mechanic by any stretch of the definition. The old radiator was leaking down low on the starboard side. The leak presented itself as foam. If I tried to add water with it running it would belch foam. The coolant was half green antifreeze and half water. I checked the thermostat by putting it in a pot of water on the stove. It opened and closed properly. The oil is clear with no evidence of coolant contamination. I used the tractor today in about 25F degree weather. The coolant I put in was one gallon of green antifreeze and the rest water. I moved 2 large rolls of hay and purposely ran in a lower gear than necessary to keep the RPMs up and warm up the engine. It took about 30 minutes and all together it traveled about a mile. When I finished and parked I looked and saw foam coming out of the overflow at the cap. The engine seemed unusually cool to the touch and the lower hose had no heat at all.
Do I have exhaust getting into the cooling system? As I said there is no evidence of water in the oil. If not that what is going on?
