Hi please can someone help me. My car was over heating so we replaced the thermostat, but it still kept over heating so we bled it to remove air. Now the pipes furthest away from the water bottle are getting hot, but the pipes closest to the bottle and the radiator are staying cold. There is still high pressure building up in the water bottle and it is bubbling. The fan comes on randomly even when the radiator is still cold.

Do you think I still have air in the system? or what else could it be! :(

Hi, Your problem does sound like a massive air lock

thats what I thought too, thank you. Any advice on how I can solve this problem please and tell where the air lock is? I have had the car running for 20 minutes with the bottles cap off, but it still does it when I drive it.

Try putting the heater to hot and the blower to max, Keep squeezing the cold hoses to try and shift the air lock. Without seeing the car i can't tell you where the air lock is.

Thanks I will give that a go :) shall I do that with the cap off again?

In theory it shouldn't make much difference as most cars should be self bleeding. But it won't hurt to try it with the cap off. Good luck with it.

Thank you :)

That's ok

That's ok :D

Most modern cars do not need bleeding as they self bleed, if the water is acctually bubling i would suggest that your have hed gasket failure. have you checked the oil level? does the water level keep dropping? what colour is the water, also is there any white stuff on the cap of the radiator?

I was hoping no one would mention the head :( The oil level is fine and the water is clear. I haven't noticed the water level drop, but the car should be cold now so I will go and check. The radiator is a sealed unit, so do you mean the water header bottle cap?

The water level has dropped, but I think I can safely say the head has gone, as when I rev it there is water coming out of the exhaust :( :(

You will get water out of the exhaust anyway as that is what the cat converts the gases to. Try changing the expansion tank cap. It sounds like its not holding the pressure, which makes the coolant boil at a lower temperature and stops it circulating properly which gives you hot and cold spots like an air lock.

Good luck.

Thank you, I have ordered one and will collect it tomorrow, lets hope that is all it is. All this advice is great, I am ruling everything out and trying to sort the problem before having to go to a garage. :(

Thank you, I have ordered one and will collect it tomorrow, lets hope that is all it is. All this advice is great, I am ruling everything out and trying to sort the problem before having to go to a garage. :(

Let us know how you get on.

I will :) fingers crossed

it is the head gasket, I went to a garage today :( :( :(

Sorry to hear that. It may have gone as a result of it over heating rather than it over heating as a result of the head gasket.

I was hoping you would get away with the cap change as some years ago my Father in Law had the same symptoms. Took it to a gargae who said it must be the head gasket. Had it changed and it still over heated. As it was a Honda engine I had my doubts it was anything to do with the head so when I saw him a few weeks later I changed the cap and no more issues.

I also had the same experience with a number of cars and changing the cap sorted those to. Must have been too late with yours.

Thank you for the suggestion it was worth a try before going to a garage and paying out for something that we could have fixed ourselves. Unfortunately this time like you say it was to late :( I should have my car back today :)