heater not working

alex henson · February 6, 2017

hi hoping some one can help me. I've owned my is200 since 2011 and will simply never sell it as it's been a brilliant car. for the last year or so the heater has only blown cold air out. I have replaced the radiator and thermostat and flushed the engine through and is still doesn't work. I run the car up to temp etc. but nothing. can any one help please?

sorcerer · February 6, 2017

Sounds like it could be the heater matrix. Same thing happened to one of my previous cars but because it meant that the whole dash had to come out to get at the matrix, it basically put the car beyond economic repair

alex henson · February 6, 2017

do you know how they determined that it was the matrix?

chr15gb · February 6, 2017

I'm not familiar with the IS200 but I'll chip in.

If you can get to the hoses in the engine bay which go through the bulkhead, one will be hot (engine up to temp and heater on max), the other will be cold as no water is getting through the matrix)

Anyone know how the hot/cold selection works? Might be an electrically driven flap, that may have failed so it never opens to let the air through the matrix??.

I've found two posts, one says remove the clutch pedal, the other is a bit more involved but neither require the dash out

alex henson · February 6, 2017

hi this is extremely helpful information. the gargling noise I thought was normal but I do remember. Berlin the smell around the time the heater stopped working so definitely think this could be the case then. only thing is both pipes going into the bulk head are hot. will give this a go at the weekend though and report back with my findings. thank you again.

chr15gb · February 6, 2017

The gargling statement is interesting, that suggests you have air in the matrix

There is a long post here about it
http://my.is/forums/f87/infamous-gurgling-behind-c-need-help-plz-415033/

TigerFish · February 6, 2017

There is a servo which controls the heater temp into the cabin. There are two, one does temp, one controls where the airflow goes. Could be the heat one. If it's like the GS, the heat one is on the drivers side of the matrix, the direction control one on the passenger side.

Sent from my Iphone using Lexus OC

alex henson · February 6, 2017

I've checked the servo in the glove box and taken it out etc. but didn't realise there was one on the driver side so will check this. I've had the car for so long now I really can't remember how long the gargling noise is there but will try both methods. I will also try flushing it through again as well. can any one advise where I can get a heater matrix from at all though if that is the problem? can't find one any where and really don't want to go to main dealer.

alex henson · February 12, 2017

right little update. I have flushes the heater matrix and expected a load of chap to come out of it but nothing. both pipes from the engine bay going in to it get extremely hot. I have checked under the steering wheel after removing the panel and can't see any servos but when the engine is a it's ideal temperature both pipes are also extremely hot. (I have the burns to prove it!) lol. I have checked the 2 servos behind the glove box and both seem to move freely and the fan is working well.

I have done some digging on the Internet about matrix failures and they all suggest that it should leak and I should get a weird smell inside and around the car, which I don't. the floor isn't wet and never has been and there are definitely no leaks from out side. I have notices that the driver side temp is a little warmer then passenger side though but it is no where near what you could call warm.

has any one got any more ideas to try? also can you advise where I could get a matrix from as I can't find one any where?

thanks again Alex

Farqui · February 14, 2017

Well done checking the servo's on both sides. I've been reading up on this for the past few days, my passenger footwell is blowing cold constantly.

Are both driver and passenger sides blowing cold all the time?

If so, then isn't there another servo that controls the cold/hot mix?

alex henson · February 14, 2017

On Mon Feb 06 2017 at 11:34 PM, alex henson said:

hi from what I can tell 1 adjust where the flow goes like feet or windscreen etc. the other adjusts the heat. they both seem to work as the heat one changes something in side so when you turn the heat down it blows out very cold air. when you turn it up the air gets a bit warmer but it's still cold coming out from it. no really sure weather to take the dash out or not as it's a big job and don't want to be back at square 1 if it's not that.