The heater getting hot quickly would indicate the water pump is OK...
As another test. Put the heater to fully cold, warm up the engine, then set the heater to fully hot. Does it respond in just a few tens of seconds blasting out hot air?
I wouldn't trust a modern car not to have an auxillary electric pump for the heater circuit tho'... What does "the book" say?
I tried your suggestion of running it without the cap for a bit, seemed to do the trick.
As I posted elsewhere in this thread. Ran it up to temp, took the cap off and ran it for a few more mins and could feel the bottom rad pipe getting warm, indicating the water was flowing.
Anyway, took it for a spin, expansion tank didn't bubble up and the fans didn't come on, so fingers crossed that's done the trick.
Cheers all!
Have something to add? Share your thoughts — no account required.
Ask the community — no account required