Coolant problem

[davmac]

^^ A bad water pump that is somehow not circulating coolant (seized pump shaft or impeller is spinning freely on the shaft) will cause overheating, but unless it is leaking will not be the source for air in the cooling system.

Is it possible for the headgasket to leak antifreeze to cause bubbles without entiring the oil?

YES

I just removed my radiator for access yesterday, and put it back on. Refilled, ran to warm, topped it off, then took it for a short road run. After I got back, and the engine cooled, it had pulled most of the coolent from the overflow. I refilled the overflow, and all is fine.

your case puzzles me.

Jim

I agree that the MX3 is not too hard to rid of air in the coolant. This assumes you have no leaks.

Based on the symptoms Electronblue is reporting my guess would be leaking head gaskets. Head gaskets can leak externally so you do not see water in your oil. It is very hard to see coolant that is leaking into the valley between the cylinder heads because it is covered by the intake manifold. Also the head gasket can have a combustion gas leak that pushes what should be exhaust into the coolant passages. Again no oil contamination, but the car will overheat.

No need to be frustrated by not knowing where the leak is. Read my earlier post and go rent a coolant system pressure tester - or ask a shop to perform the diagnostic. If a shop does this you will pay ~$100 but will finally know the source of the problem.

[mx3driv]

try puyting the car in nutural and reving it to about 3000 rpms with the colant cap off. and add coolant to it as it is reving. do this until it will no longer take any coolant. you should not have any bubbles in the raditor after this. i do not know which size engine u have but i did the timin belt and water pump on my 1.6L mx-3 and the pump is a pain in the neck. hope its not your pump you have to take the timin belt off to get to it...