No hot air from heater!

[Rich25i]

Hello, Just put the head back on 320i touring and now the heater inside the car only blows cold air. Is this an air lock? or something else?

[Grantley]

Sounds like it could be an air lock, I,m guessing u had the heater on hot when you refilled the system ? It might be worth checking that the heater valve is still working just incase. Other than that I would suggest bleading the system with the heater on hot and blowing out air. Keep the coolant level topped up and watch for any sudden drops in the level signaling escapeing air, might be worth haveing another person in the car to let you know when the hot air comes through.

[Rich25i]

Thanks for the help. Will try this asap. Where is the valve?

Thanks

[craigieeb]

best thing you could do mate is to undo the bleed nipple on top of the thurmostat housing, have the engine running, and the heaters on full hot when all the air has come out of the bleed hole and its just water coming thru just tighten the nipple up, and you should have hot air

[ian332isport]

Probably an airlock as discussed above, but seeing as you have just put the head back on, it could also be the heater hoses on the wrong way around.

If you do this, you can usually hear a dull thumping noise from the heater valve as the revs increase.

Ian.

[Brianmoooore]

If it's an airlock, then the engine normally rapidly overheats, with cosequent risk of head cracking.
What does the temperature gauge do?

[Rich25i]

The temp gauge started off by just going and going untill it reached 3/4 then i turned it off and waited for the engine to cool re bleed system. now it sits at half way, drops off when thermostat opens and goes back to half way. but no hot air.
I think its due to me doin it by myself and not filling the coolant tank up as it drops. Will be doing this on sun with a mate so im hopein this is it.

Thanks for all the help

Rich

[pauldeacs]

Im having similar probs with My E30 at mo after a engine swap. which hose goes to which outlet/inlet on the heater matrix as i have a feeling i may have them wrong way around


also when i filled the system from empty it didnt seem to take much water before it was full. started engine and had a continous jet of water from the bleed nipple as advised but after a while only one of the hoses to teh heater matrix was hot (matrix was flushed thru so i know its not blocked)

also bottom rad hose was stone cold, any ideas?