Hello Group -

I recently bought a house which has a driveway with a pretty nice
slope.
When I park my jeep (facing downhill), my coolant bubbles up and
returns to the reserve.
Does anyone know why? Is the car over heating? My temp gauge shows
about 200 all the time when I'm driving..
The car is a 1998 Jeep Wrangler. If you have any insight on this -
could you please email me at chelelmz (AT) optonine (DOT) net. I would truly
appreciate any insight the group can share with me.

Thanks - Matt

chelelmz wrote:
not a real good idea to post your email in the clear, too much spam.

my two cents on this.

Your system has some expansion and probably a bit of air in it.
When you park the pressure drops to the point the little valve in
the radiator cap will open up and allow excess coolant (usually air
if your parked level) out and into the overflow bottle. Since your
parked nose-down it's going to be mostly water as the air will
collect in the upper hose and engine.

It could be you simply need a new radiator cap.

Other than that, it's normal.

--
DougW

DougW wrote:

Close. The pressure needed to force air/fluid out into the overflow is the
system pressure - 15 PSI nominal. The return direction to suck fluid back
into the radiator/engine requires a very small vacuum. Agree on the
result - need a new cap.

You also need to bleed as much air as you can out of the system. If you
have an air bubble that gets caught in the rear of the engine when you shut
down, the temp can rise pretty high which will force even more fluid out
where it should mostly air escaping. Parking off-level, especially nose
down, can cause some screwy radiator problems if you have any trapped air.

--
Will Honea