Is there any oil in the coolant?ViktorNova wrote:... Temperature stayed in the normal range and heat blew hot, but there seemed to be abnormally high coolant pressure - when I parked the reservoir cap was hissing and radiator inlet hose was noticeably less squishy than normal. ...
So other than running a compression test and changing the oil filter, what should I do now? ...
You can rationalize the firm hoses but that hissing is not normal, worth following up on. I would check the coolant for exhaust gases too, just to cover all the bases on the blown-head-gasket front.