[Randy Kohrmann]

After replacing head gasket because I was getting coolant in my oil and blowing white smoke out of exhaust pipe I may be still having an issue. Now when I run it, it blows coolant out of passenger side underneath ( maybe reservoir). It has tremendous pressure build up in radiator even when it has cooled down hrs. later. I think it may be building pressure from motor compression. I fear I may have blown another head gasket but, their isn't to much coolant in oil and hasn't been smoking to bad. As it sit and heated up in shop, steam was rolling off of radiator cap and fan did come on after a bit. Then, motor did die but temp light never did come on. I ordered a thermostat, head gasket, water pump seals, propeller shaft. When I removed return line off of radiator it also had alot of pressure their also. I took cover off of water pump and ran motor a minute and its spinning.
Does anyone have any ideas what to look for because I'm about out of ideas?

 

[Sport4x4]

Definitely start with that new thermostat. Better yet first try running it with no thermostat and see if it improves.

 

[BadM0nkey]

I am certainly no expert here but it bothers me that there is high pressure even when it cools down. I would expect that the pressure would eventually equalize through the overflow. Even though my fan was coming on, it was simply not spinning fast enough and replacing it with one from Ebay fixed my problem. If you change the oil enough that you no longer see antifreeze and it stops coming in then I am wondering if it is a clogged overflow vent and a poor fan.

 

[AZTrail]

Make sure your radiator is full to the top start up the motor without the rad cap on and see if you get bubbles in the coolant in the rad neck, let your motor warm up good, bubbling would indicate a blown head gasket or some leak in the combustion chamber allowing pressure to enter the cooling system, sure fire test and easy to do.