what's the swirl tank for?

[Stopherson]

Can anyone tell me what the swirl tank does on a serpentine engine?

I'm getting slightly erratic temperatures in traffic at the moment, but the expansion tank always has the same water levels in it. The fans are OK and the thermostat seems to be working.

Although the expansion tank level is always the same the swirl tank was half full - I topped it up but problem repeated. I would have thought that the expansion tank would be the highest point in the cooling system in order to remove air locks but the swirl tank seems to be performing this function at the moment.

Is this responsible for the temperature fluctuations (abour 100deg in traffic?)

thanks

Chris

[Stopherson]

...ask a stupid question!

[Stopherson]

So to remove an air lock to i run the engine with the swirl tank open, do i have the expansion tank also open?

Any ideas how to check if the expansion tank is blocked?

Much appreciated

Chris