Heater not working

[Alvis]

Hi all
I have a 2006 Toyota Hilux which is had problems with the heater. So about a month ago I flushed the heating system which worked for about a week and then got gradually cold again. so I did this about a week ago and it started again. Really annoying and it's getting cold can anyone help ?

[BAT091]

Heater core is blocked ?? Or farked for that matter...

[Alvis]

Don't know but I have found two hoses on the passenger side of the firewall . I have run water through both sides and the water is running clear .So does that mean that the Heater core is blocked ?

[Hellbound]

Could be the actual dash mechanism thats not working right. Take it off and keep removing bits until u can see the metal rods and linkages that should be attached to the heater core - if coolant is passing in AND out of it ok then by bets on the linkage being stuffed...

[mattwhite]

Old thread I know. I've got one to repair next week. The core is flowing and hot and the cables are free. Just wondering if there's a known fault and repair been reoccurring. Thanks in advance for any heads up.

[johnwood]

Whats wrong with your one to repair? The dials might move but the cable might not?

[mattwhite]

Plenty of air but no heat. The cables move as do the corresponding arms on the outside of the box. It's like there's a flap come away from a rod or something. I'll report back when I find it. Just thought I'd ask.

[bennyc10]

I have a similar issue however it seems my passenger LHS vent is actually blowing hot air.
I stripped the dash down and found nothing mechanical wrong with heater box. All internal flaps and dampers appear to actuate as intended.
Following this I flushed the core individually by disconnecting inlet/ outlet at firewall and found clay like material come out during the flush.
I have reassembled and will top coolant up and run this evening.
2008 A/T Hilux w PTC heater.

[mattwhite]

Just reporting back. Flushed the core just to confirm. Definitely good flow and heat. Removed the glove box and l/h footwell vent and I could see the heater control flap. I haven't seen one like it before. It's like a curtain arrangement. On cold the curtain rolls under the core and stops air flowing through the heater. On hot the curtain blocks the air bypass and all the air has to go through the core. Not sure what the curtain arrangement is made of but this one had lost some sort of lining and all that remained was a mesh type material and so the air was free to bypass the core even on hot.
I rang the local parts and was told I had to buy the entire heater box for $1250 retail. The local dealer had done one but apparently there are dozens in Perth ready to go so I'm not the first. If you want to check one yourself just rip the glovebox and the foot vent. You don't want to be able to see through the curtain.
This may never get read. Might help someone one day though.

[PRS]

Matt
This style of HVAC box was developed by Denso to be much more compact than traditional "blend Door" style HVAC boxes. It doesn't need the physical size to allow for opening and closing doors inside.
The new Denso style door is more like a cavity sliding door than a swinging one.

The door itself is made from clear plastic, very much like a piece of laminated paper without any paper inside.
There is a fine stainless mesh screen that supports the clear door from bellowing inside the box, caused by air pressure from the blower fan.

These doors are operated by a cable sub assembly that rolls or winds the doors through their range of operation. These cable sub assemblies fail very frequently and no longer operate the doors correctly. They are like 3 very fine wires inside a moulded plastic outer, with a dial on each end. One dial connects directly to the sliding door on the HVAC box, the other to the control knob behind the dashboard. I've replaced countless on Yaris's and other Toyotas.

Ref fig 87-15


I have replaced many heater cores in 2005 -2015 Hilux's, but never seen and issue with the actual sliding door arrangement. Thanks for the heads up, I'll keep a keen eye out for this issue.

[mattwhite]

Ah all good prs. That makes sense then, the plastic has gone leaving the mesh. Yeah I'm familiar with the cables and if one more person tells me it's a cable problem I'll scream. Hahaha

[jiggins]

Hi guys,

I noticed a few months ago the heater not working properly and as the weather wasn't cold I didn't worry to much but now as the weather is cooling off I'm starting to feel it of a morning driving to work.

After a day out yesterday and the wife telling me the heater is working and me saying it's not almost all day we discovered that the passanger side had heat coming out and the driver side was cold.

I ran the motor today for about 10-15 minutes with power heat on checked the heater hose temperatures and both seem to be running at around the 45-50C mark. I kicked the heater and fan on flat out, the passanger side started warm for a few moments and driver was cool but then the temperature dropped out of them both.

I rechecked the heater hoses with the fan/heater running and the temp was still reading the same but the out was running colder at around the 35C.

My original thoughts where the thermostat not working. But after 4WDing for hours on end yesterday I would think it would have warmed up enough to run the heater. The temperature gauge needle seems sit in its normal position.

I will re test the heater hoses tomorrow after a drive home from work.

Is there anything else I should look at or advise as to what it is causing the problem?

[jiggins]

So after almost 12 months of freezing my butt off travelling to work last winter as the heater was not working I bit the bullet a few weeks ago and had my mechanic look at it.
After 2 weeks 2 visits to my mechanic, an auto electrician and $300 plus dollars later its my turn.

So I pulled part of the dash apart and fiddled with toggles and all flaps are working fine.

I flushed the heater core with the garden hose and some crap came out. Cool it was blocked. Back together and running at normal operation temp I have heat now from the Passenger side vent only at around 50Deg C the drivers 30Deg C if I'm lucky.

I've now tested the core itself for temp and with fan off I get temps around 65-72 Degrees across the core. When I crank the fan to full tilt the core end closest to the in/outlet pipes holds at 65-70 Deg while the middle drops to around the 30Deg mark and the driver side some where round the 40-45Deg mark.

My conclusion is the core is still blocked or at least partly blocked.

Is there something I can pump through it to unblock it or am I flogging a dead horse and should just replace the core, If so can it be don't without removing the entire dash?

I have a limited time frame as I leave for the high country Good Friday and would like it done before I head off.

Any help is much appreciated.

[fracturedranga]

Id take it into a radiator mob and get them to chemical flush it.

[Hobbie]

Hi guys, new to this. I have a 2008 Hilux kun26r, and my heater is blowing hot air from the passenger side vent and cool air in drivers side, but if I close the pass air vent it tends to blows warmer air on drivers side. Heater core has been flushed out, heater box removed and found all flaps operating. Any ideas. Thanks in advance

[Hobbie]

Hi guys, new to this. I have a 2008 Hilux kun26r, and my heater is blowing hot air from the passenger side vent and cool air in drivers side, but if I close the pass air vent it tends to blows warmer air on drivers side. Heater core has been flushed out, heater box removed and found all flaps operating. Any ideas. Thanks in advance