I have a 95 Honda Accord LX that has a 2.2 L non vtec. After the car is cranked up for about 15 to 20 minutes it starts overheating. It is blowing steam out of the radiator overflow hose. I have done a compression test to check the head gasket all cyinders hold good compression. I have also checked the fans to make sure they are working properly and the thermostat. What could cause it to build up pressure like that?

 

I would suspect that your thermostat is stuck shut and not opening to allow coolant to circulate through the engine block. Have it changed, replace the coolant and the radiator cap as well. Honda OEM parts only...No aftermarket !! Also, be sure your radiator and heater core hoses are all in good shape...Any doubts, replace them all. How about the radiator...Any leaks from top or bottom tanks...You might need a new one if the core is clogged up.

 

Is it overheating by temperature gauge, or just the steam blowing out? If it's only the steam then maybe its just a bad radiator cap.

 

I have replaced all the hoses allready and they are not leaking. I have also checked the radiator and there are no leaks from it either. As for the thermostat, I did the test on it and it opens up. It is overheating on the gauge after about 15 to 20 mins of driving and once it starts to overheat it is blowing steam from the overflow hose (not water) like it is building up to much pressure. I have also put a new radiator cap on it also.

 

Did you do a compression test or a leakdown test? What were the readings?

 

There is also a combustion gas test you can do for ~$35 (~25 for the kit and ~$7 for the test fluid). It will test for combution gases in the coolant.

Just another idea if you can't get your hands on a leak down tester.