Friday, September 23, 2011

My car keeps losing coolant from the reserve tank after it warms up?

I have a 1997 Mitsubishi 3000 GT, for some reason it keeps losing coolant from the reserve tank, after you turn on the car and drive it for 20 or 30 mins, I come to a stop I see that it is releasing the water from the hose on the reserve tank. I have already taken the car to a mechanic and 600 dollars later I am still having the problem, the following are components which I have already changed, radiator, thermostat, cooling fan thermostat switch, top and lower radiator hoses, bypass hoses, oil, oil filter, spark plugs, spark plug wires, distributor cap, distributor router. The only thing that鈥檚 left is the water pump. I have checked the oil and it does not seem to be mixing with the coolant. Any suggestions.
My car keeps losing coolant from the reserve tank after it warms up?
sounds like a head gasket leaking a pressurising the radiator.usually when its over 175,000 miles.
My car keeps losing coolant from the reserve tank after it warms up?
I assume you are not filling the reservoir tank to the top. Full is usually half way or less on the tank when cold this allows for expansion of the coolant when it gets hot, if you fill it cold it will run out. If you are not then I would remove the radiator cap (when cold) start it up and check for constant bubbles which would indicate a head gasket. Also if your heater works fine then I would look else where before the water pump.
The level on the coolant reservoir will always go down a bit while the car is running, that's 'cause the engine will pull in all that liquid in but, once the engine is off, some coolant will slowly come back to the reservoir, if you pour too much coolant in the reservoir, this container will dump some of it out thru an attached hose on the reservoir itself. You shouldn't worry much about this issue unless you see the temperature gauge in your car going over...if you car over heats then you have a problem.
One possibility is an air lock in your coolant system, this happens when you had a coolant change and it was not bled properly. As the engine gets hot the air in the system pushes the coolant out to the overflow bottle/ reserve tank.



My suggestion is to completely drain the coolant again (to bleed it properly involves tilting the car to the opposite side of the drain plug and switching the heater to max setting to release coolant in heater matrix). Another thing is always do a 50/50 mixture of water and coolant as too much water in your coolant system will just burn away or evaporate.