Water Pump or Headgasket or neither??

[VanMan_Jas]

Right...

My van started overheating due to an airlock. SO i bled the system and it was fine for the first journey, then overheated again.

 

I knew my heater matrix was leaking, so ive just changed that and also replaced the top rad hose which wasn't too good.

 

So now everything should be ok. But, if i leave the engine to idle, an airlock builds up. The heaters still blow cold air.

The top radiator hose is just full of air. Even after bleeding, it build back up again.

 

The fan cuts in and out again, but the heaters dont warm up.

Am i right in thinking that if the fan cuts in, then the thermostat is fine?

 

Ive tried bleeding the system but cannot get rid of the airlock.

 

So i started thinking maybe its the water pump? If thats broke the water is not being pushed around the system?

 

Any ideas or checks to do to narrow this down?

 

Cant believe i spent a good 5 hours removing the dash and replacing the heater matrix and it hasnot solved the problem!! Arrghhh..

[Dave C]

when you blead the system,did you have you leave the reservior cap off, & squeeze the hose,while ticking over?

 

Also,i dont know how much truth is in this,but apparentlly you should have the heater contol on hot when bleeding.

[Andy_GTi]

if your getting air in the system that quick i would say it's getting air from the cyclinder, ie being pushed throught the head gasket or !!!! you have a knackered water pump/leaks so there for suck a bit air.

 

when you start the car does all the hoses het hot ?