High pressure on the upper radiator hose?

Question

It's a '96 Ram Van, 5.2L V8. I just put a new thermostat in yesterday, everything is back the way it should be, it ran fine yesterday, but after driving it today, I noticed the temperature was getting pretty high. Popped the hood, and the upper radiator hose is like.. solid. I couldn't put a dent in trying to squeeze it. Is this normal? I'm almost thinking the radiator cap is bad, because it's supposed to open up at 16psi to access the overflow tank....

Answer 1

Your thermostat is bad. The water should be able to flow through the area where the thermostat is mounted. If not, it'll cause high pressure in one or the other. If it's THAT high.. DON'T drive it. It can back up so much pressure that it'll blow your cooling system. (probably at the hose upper hose you mentioned.)

  It's possible whoever put in the new thermostat put it in upside down. It's a common enough mistake to not be all that embarassed about.. To be safe, I'd just replace it again. Should cost less than $10 for the part and gasket.

   I'm not terribly familiar with that engine, but the lack of overflow function with the cap can be explained by the pressure difference. If the system's high pressure point in on the other side of the thermostat from the cap, it won't release to the surge tank cause the thermostat's stopping the pressure from reaching it.  If that's NOT the case, I'd replace that too.  

Answer 2

you may have got bad thermostat or the head gasket is blown on it that will build up a high amount of pressure,if it didn't have any problems before this id try and see if the thermostat was in right,when you reverse one they will do this,the pointed end goes towards the radiator always on those,you have to burp that system also or the air pressure will build up but you wont have no coolant filling it,good luck.

Answer 3

Your new thermostat is either in backwards, or defective. DON'T keep driving until you fix it! What the previous answerer said, too.

j- The Gremlin Guy -