1.8 TDCI Focus heater (MK2)

[Matthen]

Hi all - driving home last night, I discovered that accelerating full throttle off a roundabout or loading the engine by accelerating up a hill made the heater blow cold. The cold would continue for 20-30 secs before resuming blowing warm. Temperature dial also drops.

Coolant was just below min last time I checked. Topped it up before last nights journey.

Any ideas what could be up? Heater works fine whilst cruising.

[shoehorn]

Air in the heater matrix from where the water level has dropped,Id suggest you may have a small leak.

[Matthen]

shoehorn said:

Air in the heater matrix from where the water level has dropped,Id suggest you may have a small leak.

I've changed the radiator cap, upon inspection the lower sealing washer was shot. Going for another run tomorrow, see if that's cured it. If not I'll get the system pressure tested.

Cheers