Daihatsu charade 1.3 1996 model. I bought the above car 3 weeks ago from a car dealer in WA. A week later the radiator overheated and has done so twice since. The thermostat has been changed twice but has not fixed the problem. The radiator cap has also been changed. large air bubbles can be seen when the cap is off which I am told could be the head gasket has gone. The car dealer is not very helpful so I need to know why the head gasket breaks down and any other information which could help me get this problem fixed. Any help greatly appreciated. Lucy Renouf

Thanks again for your speedy response I have had the car checked out and unfortunatly it is the head gasket. I am having to take the car back to the car dealer and hope he can fix it for me. It did help so much for all the comments to understand more of what the problems were. Thanks again Lucy.

The thermostat problem caused overheat, because overheat your head gasket maybe broke up and leak,
1. check the tail pipe see if there is steam blow out.
2. check the oil cap,see if there is steam white bubbles

If you got, that probably your gasket broken.

3. put a piece of cardboard in the front of the engine, open the radiator cap. fillup water.

4.start the engine and let's run at least 30 minutes, see whether it overheat or not.

5. check the radiator water, see if it is circling. if it is not circling, probably the water pump doesn't work.

6. you will find out whether leak or not.

The cheapest way to stop engine gasket leaking, if it is not too big, go to parts store get a bottle of good stop leak and try it. sometimes you can stop the leak area. good luck. Frank

Hi,

In its simplest terms, the head gasket is the spacer/insulator between the cylinder head and the engine block. When the piston (in the block) moves upward to compress the air/fuel mixture (against the cylinder head), tremendous pressure develops inside the combustion chamber. The pressure will find any easy means of escape to expand. If the gasket is defective, the pressure will pass through that gasket and enter the water jackets (where the collant flows through). The pressure/air bubbles will ride the coolant flow and eventually end up inside the radiator and would then be visible as you have posted.

Incidentally, the gasket may be OK but the cylinder head could be warped and the same fault would also be exhibited. This is especially more so on aluminum heads.

Both the gasket problem and/or the warped cylinder head could have resulted from a prior overheating problem.

Corrective procedure on the air bubbles would require top overhauling wherein only the cylnder head is removed. Of course once removed, your mechanic would be able to inspect the pistons and its sleeves and could decide if a general overhaul is required or stick to the cylinder head work. A top overhaul also requires cylinder head gasket replacement.

Unto the overheating problem, you may want to check the water pump, thermostat, fan, fan relay and fan clutch. It may also be to your added advantage if you would have the radiator flushed/cleaned as well as the water jackets. Some mechanics especially in warmer regions opt to completely remove the thermostat and permanently wire the fan to always be on.

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.

Thank you for using FixYa.