Coolant problem

[Sandip]

I've got a slight problem with my coolant level, seems to be losing coolant, the car isn't heating up, no signs of water leakage on the floor, no gunk on the oil cap. What i noticed was when i opened the expansion tank there was a hiss, so the pressure is there but as i opened the cap the water level went up. (car turned off).
The only thing whats been sounding strange recently is the auxiliry water pump, could this be causing an air lock in the system?
Any ideas?

 

[FazS3]

it would hiss when opened if the car is still warm from being started or driven,was it bubbling though?how much coolant isit losing?can you smell coolant at all?

 

[Sandip]

smells normal, its not bubbling and the temp is on 90, hard to explain how much its losing really, when you look at the expansion bottle i filled it 2cm above the join and basically went back down towards min the day after, topped it up this morning done a few miles and it seems to have stayed right, its just seems the lose it suddenly now and then

 

[Jacko4130]

Have you made sure there is no air locks in the system?

 

[Sandip]

Thats what i was thinking but where would the air lock of happened?

 

[abdus]

air lock anywhere in the system.

remove the expansion bottle cap and start the car and let it idle for some time. If there is any air trapped, you should see bubbles coming out. They will stop after some time and top up if needed

 

[Sandip]

Thanks for that, i'll give that a go tomorrow, hopefully should cure it

 

[Clach]

you will lose coolant after that procedure, so have plently to top up with..

 

[simch]

Remember to have your heating on max when you do this also.

 

[abdus]

thanks for pointing this out simch, i missed it in my post