Possable airlock?? need help!

[buzzlight]

I have a weird problem with my cooling system, about once a week my temperature gauge goes up high and my heaters go cold, if i stop the car and remove the water cap let the built up air go it instantly returns back to normal running temperature. I've been advised to replace the thermostat but most of the time the temperature seems to be ok and with the current cost of replacment i'd like to try all avenues first. Someone has also told me that it could be an airlock if so how do i clear?

 

[Tom Two]

Airlock

Does sound like an airlock.

I had a similar problem in my last car and it was due to a sharp bend in a pipe that trapped air, bad design

I had to 'rattle' the coolant pipework to free the air when the engine was running at temperature, watch out for moving belts when doing this. Is you expansion bottle got the right level?

Hope thats usefull, TOM

 

[buzzlight]

Airlock

Thanks Tom I'll give that a try?

 

[Brad]

Try more pressure

If you have the remote header tank you can undo the mounting bolts and string the tank up high while filling.

 

[Spyder]

Re: Try more pressure

Sounds about right, if there is air in the system it is easy to rectify.
With the engine cold remove the radiator cap from header tank(located somewhere on drivers side) then start the car and allow it to run until the temp gauge in car reads just under normal temp, occasionally rev the engine to surge the water through the system but don't over do it. Then when the temp is just under normal and the water is hot but not BOILING replace the radiator cap and every thing should be fine.
If however it continues to persist then check your water level reg' as there may be a hole in one of the pipes allowing air in.
I don't think it is your thermostat.

 

[J Moore]

Re: Re: Try more pressure

When I changed the coolant on my 1.6SX I managed to get an air lock which gave similar symptoms you are seeing.

It turned out to be in the radiator. The 1.6SX radiator fills through an expansion bottle, and the radiator wasn't filling up correctly.

The radiator is fitted with a plastic bleed screw though. Located drivers side, near the top on the back of the radiator. I ended up removing it and topping up there. This sorted it. It took about 3/4 litre. I've not needed to top up since, but would now do this using the expansion bottle filler now that the system is air free.