Hi all,

I have a '92 Grand Caravan 3.3L.

When the engine is running it runs smooth, runs cool, and all is ok.

When i stop the engine however, the engine starts to boil-over into the coolant overflow tank.
It does this for quite a few minutes and at such a rate that it spills most of the contents of the overflow tank onto the ground.
Then when the engine is cool, ill check the radiator and find it needs >1L to top it back up again.
It does this ever single time i stop the engine... so as you can imagine, filling up the radiator all the time does become quite annoying.

Also, when the engine has cooled down, the top radiator hose colapses in on itself.

I have tried a new radiator cap, but 2psi lower pressure than the standard one (in an effort to stop the hose colapsing)... the boiling over after running still happens, but it has solved the hose problem.

Does anyone know why this is happening??

The normal cap is 16psi, the one i tried to stop the hose from colapsing is 14psi.
To me it almost sounds like it actually needs a higher rated cap to stop the boiling over.

Thanks for any help.

 

Did you try replacing the cap with a correctly rated cap? Your old cap might just be defective, as a collapsed upper hose is usually a sign of a bad valve in the rad cap.

Are your cooling fans running?

Have you checked your thermostat?

 

Well i only bought this van a few months ago so im not sure if the cap that came with it is the correct one or not.
I guess i should get into a NAPA and buy the correct cap.
The correct cap may fix the colapsing hose problem, but i cant see why it would fix the boiling over problem.

The cooling fan is running.

The thermostat was replaced ~3 months ago.
The engine also heats up and operates as you would expect with correctly working thermostat and cooling fan.

Its just this boiling over when turned off problem that has me baffeled.

 

Did the correct cap fix the hose collapsing problem?

Does it make a difference if you don't run the AC as to what the motor does after you turn it off?

 

Do a cylinder leak test, take the rad cap off to see if the water level rises when there is air pressure in each cylinder.
you may have a head gasket with a slight split, and it could still run fine.
Does anyone know of a forum similar to this one but for Chrysler-Dodge-Jeep Dealer techs only?