Heater (climate control) goes cool at idle
 

It was very chilli tonight, and couldn't really get the interior temp of the car very hot. It was warm enough, and comfortable, but wanted a real warm up after being outside in the freezing cold, but I was surprised that putting the Climate Control (heater in old money) on "HI" didn't make it hot.

I then noticed that the climate control was blowing cool as the car sat idle, but then went back to very warm (not hot) when on the move.

The engine temp gauge never moves off "middle".

The Air Con was turned off (Econ).

I ran a diagnostic check in the dark, and only the sunlight sensors errored; presumably because it was dark? Codes 21 and 22.

Any idea anyone?

Jim

Mine is too much @ 25 let alone high, static or on the move. Have you tried the same in econ mode, if it's more consistent then I would suggest a regas or at least get it tested.
Temp gauge should remain on half way.
I think the error codes are normal in darkness.

Yep, same in both modes.

are your coolant levels ok ?

all i can think is air lock. diky water pump oir sticking thermo stat or poss a blockage im heater matrix (are both sides cold ?)

I'd put my money on the stat if it is stuck open the engine won't reach the correct temp. that assuming the coolant levels are OK and the heater is functioning as it should.

hth

Mine does the same after a while at idle. Seems to me like it is an air lock in the heater matrix, in fact I can hear water gurgling behind the dash when I blip the throttle. It has always done this, right from brand new. The dealer has tried to fix this a few times with things like 'loose hose clips' 'vacuum coolant refills' and even a new radiator, but the fault still persists. I have just learned to live with it, and blip the throttle every now and then on a cold day in standing traffic!

Jim, do you get the same water gurgling noises?

I would have a go myself to get out the airlock, but I have heard that the KV6 is picky about being refilled with coolant, so have shyed away from fiddling.

Anyone any ideas about bleeding this out, I have had a good nosey around the coolent system and cant find any bleed valves in the heating pipes at all unless I am missing something? The only bleed valve I can find is on one of the radiator hoses.

I assume when you have had a coolant change you had it refilled again via a vacuum fill? you should not have to bleed it, when you have a colant change it should be vacuum filled and that will see the end of any airlocks.

Thanks chaps.

Butty - no, I don't get any gurgling noises. I will do a thorough check over the cooling system this weekend. I had a similar problem in my B a few months back, and it was an air lock.

Jim

Just out of interest for those of you with this problem do you get equally warm air through to the passenger side of the car or is it noticeably cooler?

Same both sides on mine.

Funny you should say that though, my wifes car had cool one side and hot the other. Turned out to be a thing called a DuoValve which I had to rebuild.