I have a problem with my 1987 Case IH 885L 4WD tractor which is driving me to despair. It has been laid up for the winter but came out recently to do two jobs. The first was subsoiling in about 200 metres of water pipe. It ran for about two hours and performed perfectly – temperature normal. Yesterday we had it on the muck spreader which was a good work out for it. It ran a little warmer than usual (about halfway on the gauge – usually a quarter) but again ran for 2 or 3 hours perfectly. While being loaded it was idling at the heap and I noticed frothy water coming out of the radiator overflow the temp gauge was back down to a quarter. We continued to use it for a few more loads and it continued to spit water out occasionally. When it was stopped I took the rad cap off which fizzed like a pop bottle. No water came out but the water in the rad was foamy and continued to bubble and fizz for a while. As I said this is an ongoing problem and the tractor has had the following work Engine strip down to replace a leaking liner seal engine/head flushed, cleaned and checked New head gasket/ all other engine gaskets etc. new radiator new hoses new thermostat New rad cap Tested to ensure exhaust gas is not entering coolant (I have access to a testing kit for this) The only item I can think of which has not been replaced is the water pump but that was newly replaced when I bought the tractor a few years ago. I cannot understand how this can be a seemingly intermittent problem. Your thoughts would be most appreciated as my mechanic has thrown in the towel!