Overheating #3 Options

[Araykhel]

I'm back to the boards and at the mercy of you clever bunch once again. Right, so some background: Prior to last February I was overheating at the most random of times, coolant disappearing and the like. Replaced a thermostat, checked hoses, added coolant, and made sure never to drive any longer than emergency would have it when I got into the red. That evolved into a full blown leaking water pump and thus I fixed the issue on my own after learning how (thanks for that).

Now, fast forward three/four months since I changed the water pump and my engine overheats, I check under the hood and there is steam blowing out of the radiator cap. I did a flush (probably horribly) when I changed the pump and made sure the coolant levels were great but here I am with an empty reservoir/ plenty to add to the radiator.

When I drained the coolant last month there was no mixing that I could see, and just yesterday after a 40 minute drive I had good temperature but my radiator was spitting fluid from the "sealed" cap.


Help me you magnificent gear-heads.

[nics]

You have an internal leak. It could be a blown HG to cracked cylinder head. Oil and coolant mixing is not always the case so you would not see a milky coffee like coolant.

The blown HG or crack in the cylinder head pushes the exhaust gases through your cooling system and this is why steam is comming out of the radiator cap. The radiator cap can only hold a certain amount of pressure and when it goes beyond this pressure, the coolant is pushed in the coolant reservoir. Since your cooling system is not a closed system anymore, this explains the loss of coolant in the form of steam.

[Araykhel]

You have an internal leak. It could be a blown HG to cracked cylinder head. Oil and coolant mixing is not always the case so you would not see a milky coffee like coolant.

The blown HG or crack in the cylinder head pushes the exhaust gases through your cooling system and this is why steam is comming out of the radiator cap. The radiator cap can only hold a certain amount of pressure and when it goes beyond this pressure, the coolant is pushed in the coolant reservoir. Since your cooling system is not a closed system anymore, this explains the loss of coolant in the form of steam.

I appreciate the responses, I will replace the radiator cap just to do something for the time being... However I can't help but agree with you nics. What can I do to confirm 100% that it is a HG?