Heater (or lack of)

[Greydog]

Hi everyone recently purchased an Avensis Estate 2.2 D4D high miles but great car apart from the poor heater??

I have carried out the normal internet searches and seen the head gasket stories, but I don't believe its the head gasket as the car reaches operating temperature (needle half way) and stays there under all conditions. In a month it has not lost any coolant, no mayonnaise under the oil cap and the oil is clean-ish. The water feed pipe to the bulkhead is hot in the cabin the fan runs and the directional controls work just no temperature.

So what controls the flow of water through the heater? The dial is at Max heat but no hot water flow.  where do Toyota hide the control valve, fuses, relay, etc I can find no information or schematics on the net? Help anyone

[Duggerz]

I may be stating the obvious but is the pollen/cabin filter in good shape? Any restriction there will reduce your output markedly.

[Greydog]

Hi Duggerz thanks for the reply

Fan operation is fine through all positions and it blows plenty of air at the vents, the direction to screen/footwell/screen etc works OK. It is just the lack of heat. I have searched trying to find schematics or some guidance to find the water control valve as I think that is where the issue is.

[Greydog]

OK follow up to my problem which is now fixed (I hope) finding any information on Toyota's is a pain I have to say any mention of lack of heat seems to flag head gasket failure as the cause, the car uses/looses no coolant so it came down to rolling up my sleeves and a bit of exploration.

1st following Duggerz tip my thoughts were "it cant be that simple" well sadly it wasn't, and as it turned out there was no pollen filter at all fitted ??? There is now though. So one possible cause out of the way.

While in there I could see the heater matrix feeder pipes and both were hot so it must be the air passing over the matrix (or lack of). I then played hunt the servo drive that controls the heat. 

Found it after digging under the drivers side dash the servo could be felt working when I rotated the heat control so time for tea and head scratching. Eventually I took off the servo to see if I could see any more or get a clearer view what was happening. The problem was the operating arm that moves the flap, the molded pin on the arm was missing changing the flap looks like a major dash dismantling job but moving the flap by hand proved that this was the issue. Time for more tea and head scratching, eventually I used my Dremel to drill the arm tapped a thread and fitted a grub screw to act as the pin. Before fitting the grub screw I dipped one end in Gorilla glue screwed it in and left it to set, All the moving bits I gave a squirt with Lithium Spray grease and made sure it moved easily, put the servo back and tried it. All working again so put it all back together. 

3 days now and still working so fingers crossed 

[TomdeGuerre]

Way to go David, I think that’s brilliant. Not only did you find the problem and fix it but you came back on here to close out the thread. 

So now that you’ve done the job and could probably do it all again in about half the time how do you feel about doing it with a video camera? Or even still shots would do. Like you said there’s virtually nothing out there to help and the amount of posts I’ve seen with owners having trouble with their heaters - bleeding, checking, going round and round and rarely do they ever get closed out. 

This post is clearly STICKY material!
 

[Greydog]

Thanks Tom

I am an old and battered bloke not young and bendy, my knees and back still haven't fully recovered  lol.

Having said that you are right pictures would have helped others more so when the weather improves I will redo with pictures.

[Notoyboy]

Well done Greydog, and thank you for telling us about your repair.  Always satisfying to work out a DIY repair which solves the problem

Hopefully it will last forever!

 

[waqar_lionheart]

Well done Mate.

Just goes to show, a bit of head scratching and determination gets the job done. Elbow grease is a given.

[jem555]

On 07/02/2016 at 3:25 PM, Greydog said:

OK follow up to my problem which is now fixed (I hope) finding any information on Toyota's is a pain I have to say any mention of lack of heat seems to flag head gasket failure as the cause, the car uses/looses no coolant so it came down to rolling up my sleeves and a bit of exploration.

1st following Duggerz tip my thoughts were "it cant be that simple" well sadly it wasn't, and as it turned out there was no pollen filter at all fitted ??? There is now though. So one possible cause out of the way.

While in there I could see the heater matrix feeder pipes and both were hot so it must be the air passing over the matrix (or lack of). I then played hunt the servo drive that controls the heat. 

Found it after digging under the drivers side dash the servo could be felt working when I rotated the heat control so time for tea and head scratching. Eventually I took off the servo to see if I could see any more or get a clearer view what was happening. The problem was the operating arm that moves the flap, the molded pin on the arm was missing changing the flap looks like a major dash dismantling job but moving the flap by hand proved that this was the issue. Time for more tea and head scratching, eventually I used my Dremel to drill the arm tapped a thread and fitted a grub screw to act as the pin. Before fitting the grub screw I dipped one end in Gorilla glue screwed it in and left it to set, All the moving bits I gave a squirt with Lithium Spray grease and made sure it moved easily, put the servo back and tried it. All working again so put it all back together. 

3 days now and still working so fingers crossed 

hi i have the same my heater is not that warm

[Mike169]

Hi to those with not so hot heaters, this may sound daft but something for you to try and perhaps report back on this forum if it worked...............................try instead of having the temp. control knob on 'max' turn it down just 1 degree and see if it's any hotter, there are reasons this may work.

Mike.

[jem555]

tryed that its still the same

[Mike169]

Hi jem555, I am assuming your temp. gauge on the dash is reading somewhere in the middle, i.e. the engine is at running temp?

[jem555]

yes it is

[Mike169]

Can you get your hands on the 2 hoses that go to the heater matrix to check both are hot, careful not to burn yourself of course.

[jem555]

yes there hot

[Mike169]

Hi, here's a page of possible problems, certainly worth a read.

https://www.google.co.uk/search?q=Toyota+Aventis+2003+d4d+heater+not+getting+hot%3F&ie=utf-8&oe=utf-8&gws_rd=cr&ei=DvHFVrOHBsz1-AGZz6cY

[Greydog]

Have you checked the servo that controls the heater flap? I have read your heater supply pipes are hot I am assuming Fan control is working and the Air direction control is working OK

Mine is the cheapo version (3 dials) Air direction Fan Speed and Temperature, I pulled back the carpet in the drivers foot-well and the servo is visible. If you get down low enough in the foot-well (damn the robot that put it together never thought about the narly old bloke that's not very bendy anymore trying to fix it) I could get my hand on it and feel the operating cam moving when the temp control was operated, my issue was that the cam should move the flap that allows air over the heater matrix. When I undid the mounting screws and removed the servo the flap operating arm is visible moving it by hand gave instant heat.

I would think the more up market digital control will have servos on both sides to allow separate passenger/driver control. I guess both need checking in that case

 

 

 

[Mike169]

Hi Greydog.

I like your reply and reading your higher up post I wonder if this is a weak point on these cars. Following up on what you wrote I have a Rav 4 2012 with digital controls for each side I am assuming I have 2 servo's?

Mike.

[jem555]

On 18/02/2016 at 5:05 PM, Greydog said:

Have you checked the servo that controls the heater flap? I have read your heater supply pipes are hot I am assuming Fan control is working and the Air direction control is working OK

Mine is the cheapo version (3 dials) Air direction Fan Speed and Temperature, I pulled back the carpet in the drivers foot-well and the servo is visible. If you get down low enough in the foot-well (damn the robot that put it together never thought about the narly old bloke that's not very bendy anymore trying to fix it) I could get my hand on it and feel the operating cam moving when the temp control was operated, my issue was that the cam should move the flap that allows air over the heater matrix. When I undid the mounting screws and removed the servo the flap operating arm is visible moving it by hand gave instant heat.

I would think the more up market digital control will have servos on both sides to allow separate passenger/driver control. I guess both need checking in that case

 

 

 

hi greydog is it easy to access is it located on the clutch pedal side

[Greydog]

Afternoon Jem

Yes it is fairly easy to access I took off the plastic panel above the pedals (2 or 3 screws) and then lifted off the footrest and pulled back the carpet. You need to be low down and you will see the servo motor assembly (black unit with a white cam on the inside face) mine is just above the height of the heater control panel. When you increase/decrease the temperature you should see/feel the white cam section moving. You will see the screws holding the servo on and the electrical plug in the bottom, when I took mine off I could see the operating arm on the end of the flap with the engine running I moved the flap by hand and got instant heat (yay) Then all I had to do was figure out the fix.