Upper Coolant hose

[sentra]

A couple of weeks ago, i started my 1994 Nissan Quest van after being parked for about a month or so. I let it idle for a few minutes and then drove it for about 200 feet.

After parking it, i raised the hood and tried squeezing the upper coolant hose that entends from the radiator to the engine. I couldn't squeeze it at all, due to what i assume was pressure buildup from a yet-to-be-known cause.

To relieve the pressure, i opened the radiator cap and some coolant gushed out, splashing onto my pants. Any idea what can be the reason for this pressure buildup?

 

[sentra]

Addition: A couple of weeks before parking it for a month, i had changed the coolant in the van following the procedure stated in the factory service manual, which included bleeding the air by opening the coolant air bleed screw.

I had squeezed the upper coolant hose a few times after the coolant change, and it was fine.

 

[JosephHarmon]

The cooling system is normally pressurized up to 17 psi. If the engine ran 5 minutes it generated enough heat &this would be normal.

There are only consequences opening a pressurized cooling system including severe burn injuries requiring emergency medical attention & coolant loss.

 

[Boomer]

It could also be caused by a leaking head gasket allowing combustion gases into the cooling system.. Do a pressure check of the cooling system.

 

[The_Eric]

It's probably fine. When you run it for a while (enough to open the stat) and the upper hose is still squishy, then there's likely air in the system. If you run it for a few minutes and the hose is stiff, then it's quite likely all the air is bled out. Remember that air compresses and liquid does not.

If it's any consolation, my Hyundai will start to build pressure in a minute or less.

 

[sentra]

Thanks for the response, guys. It appears everything is fine. Boomer, i am pretty sure the head gasket is not leaking.