Rubis

Hi! My first post here and yes I did read many threads about similar problems but didn't get a solution for my problem.

So the car only blows cold air to the drivers side of the cabin. Other side gets both cold and warm as requested. More accurately the face level four vents from left(driver) to right(passenger) blow:
1:cold
2:a little warm
3:hot
4:hot

The leg vents:
driver:cold
passenger:hot

Windscreen vents I didn't check but I presume similar results.

I took the car to service and for my surprise they said the servo controlling the cold/warm flap is working as it should and the flap itself is moving as it should. All buttons/controls do what they should and there are no error codes. So it doesn't matter which way the flap is. The result is cold air anyway.

What can it be? And thanks for all the help you can give.

Edit: Ah yes the car is MY2009 if that matters

technixp

Hey, i have the same problem.

Already tried ( and failed ):

1. Checking coolant levels
2. Flushing heater core

Does 1st vent blow warm air if you manually close vents 2,3,4 ?

Rubis

Hi! I went and checked a bit more and yes the first vent blows warm air when I close the others. Not fully hot, only warm. It seems we have the exact same problem going on. Also I tried the filter button (between auto and front/windscreen heat buttons) and the warm air from the drivers side changes to cold as well. If I turn the filter off the air turns to warm again.

Also I checked the windscreen vents and the passenger side blows hot and the drivers side blows warm but not hot.

Let's keep each other updated if we find something! Thanks for your last message.

ibidu1

iTrader: (1)

Maybe a clogged heater core in the dash, have you tried reverse flushing it with water? Undoing both inlet and outlet water hoses on the core, and putting a water hose on the outlet side to see if any junk comes out. Or maybe a clogged thermostat?

Tried this when you see the problem, try mashing the pedal under load while driving. See if it fixes itself, if it does it could be related to coolant and the heater core.

You said they checked the flap servos and there ok, maybe the heater core is so clogged that only partial of it is working.

Rubis

The car is going to be flushed tomorrow in the shop, but I was reading about this from the IS forum and it seems that it will only partially remove the clogging once done. So the flush should be performed again after some time and then again and so on. I'm starting to think I should just do it myself because it would be crazy and expensive to do it multiple times in the shop.

Here's a link (for technixp) to the IS forum where someone drawed a nice picture explaining how the heater core works in the IS model. It's got to be the same principle in the GS as well? I didn't know it can clog like that causing the core to only work partially.
https://www.my.is/forums/f115/heater...41/index2.html

Technixp is your car really blowing from the passenger side as hot air as it should? I don't think mine is. It's warm but I think it should be warmer.

ibidu1

iTrader: (1)

Its very easy to do yourself, this video should help you.

Rubis

Thank you! I technically know what to do but I don't know where the heater core is located. Should it be done from the glove box or can it be accessed from under the hood?

Rubis

All right. The car's cooling system was flushed in the shop and it worked. Now it can blow warm air for the driver too. The shop told me it would be wise to repeat the procedure after a week or two when the fresh coolant has cleaned the heater core a bit more. I agree. Maybe I'll do it myself this time.

Technixp you said your system was flushed too but it didn't help? Unfortunately it looks like your heater core is clogged way more than mine. Maybe it can't be saved and needs to be replaced?

technixp

Rubis, Glad that it worked for you!

I did flushing by myself. Maybe I was to gentle
My cars passenger side is so hot that it burns

Rubis

Maybe more crap will come out your system if you did it again. Did you flush it with water? The shop used some kind of a product which is meant for cleaning the system. I believe they mentioned it was from Bosch.

And thanks for the picture. Now I see it can be done from the engine compartment. Can you tell what diameter hoses will fit?

ibidu1

iTrader: (1)

Did you try reverse flushing it? Also you can try putting white vinegar and let that sit while raising both hoses up so the vinegar can break down any crap thats in your heater core.

sha4000

iTrader: (1)

I flushed my 460 with CLR last year after the dealer did a flush and showed me all the crap that was coming out, the tech said it looked like the PO put some stop leak in the system. The heat would come back but eventually it would blow cold only on the drivers side again. I did another flush a couple of weeks ago and still pushed out some crap but my heat is back again.

technixp

I used vinegar. My mechanic suggested that.
After flushing with hot vinegar i have connected garden hose for several minutes. well.. did as in CrisFix video.

Hose outer diameter is about 1.9cm. Use original clamps to have secure fit.

technixp

By the way driver side started to blow warmer air after driving in twisty roads. I think there is still some air in the system

Rubis

That's nice to hear! I mean about the warmer air. If you know how to be careful I would suggest thick gloves and opening the coolant cap slightly to check if air comes out when the car is up to operating temperature. This way you should get at least most of the air out if that is the problem. If no air comes out you know it's just more flushing ahead.

Driving on twisty roads did you mean turning a lot or a lot of power? When you press down the accelerator and let the engine work on full revs it makes the water pump also operate with full power. This creates good pressure in the coolant system and is indeed the way to clear the clogged crap from HC. Driving like a lunatic fixes so many problems with cars...