water leak



This started on Monday night, after driving the car and turning it off, it dumps water out of the overflow :?:
The water temp is fine (needle sits at about 11 o'clock), oil temp is fine, I checked the level in the radiator this morning before I left home and it was just below the cap.
I noticed the rubber seal on the cap was looking a bit chewed up- would this cause it?
Cheers peeps


If the seal in your cap is gone- it could well be the cause, so get that changed first of all.

If that still doesn't solve it, then there may be something causing excessively high pressure in your cooling system, causing the spring in the cap to lift and vent water out (thats why its there afterall).

From my experience, i have seen several cars suffer this due to head gasket leaking between combustion chamber and water jacket (or in a rotary, the o-rings leaking in the same manner)

It could just be that your car is getting hot in the summer sun due to another reason i guess- maybe blocked rad, defective water pump.

If you suspect it to be gasket (i hope not :() then get your car to a garage and they "should" be able to test your header/expansion tank for traces of exhaust gas.