I'm new to this site and i am hoping someone can help me with my problem.
I have a 1995 f-250 7.3 powerstroke 4x4.I've got roughly 225000km on the truck and have owned it since new.It's been an excellant motor and truck up until recently.Witin the last year or so upon cold starts and after running for several minutes the degas bottle fills right up and overflows through the cap(brand new ford cap)This seems to go on until the degas bottle appears about half empty and then subsides.It doesn't seem to happen on warm starts.The first time it happened I had started the truck and driven 5 minutes down the road when I realized the temp. guage had risen past the usual position.Upon checking underhood coolant being released by the cap.2 minutes later it stopped and the guage returned to normal.I attributed it to a possible sticky thermostat.Now after changing coolant,cap and thermostat I still have the problem and it appears to be getting worse.I had it in to Ford but they couldn't find anything.I believe this was due to them starting it warm.It seems it pretty well has to sit overnight to completely cool down.What is going on and has anyone else experienced this?

 

Mine was doin the same thing about a year ago, it would over heat all the time, but I would never get heat to come out of the vents, the overflow would fill up and blow coolant out, finaly i replaced the thermostat and that fixed all my problems. the symptoms kind aound like a stuck 'stat, but you said that you replaced that. I wouldn't think a cavitation problem would stop after the truck is warm, or a head gasket. have you mechanic do a pressure test on the truck's coolant system when it is cold, if the pressure slowly leaks off then you definetly have an internal leak somewhere.


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