Interior Heating Blowing Cold

[anchorman]

It isn't really a function of time, it is more about work done. In winter things take a turn for the worse and it really slows down. I used to travel about 6 miles to Buxton and first thing on a frosty morning it would have a job to be blowing warm for most of the way. That included about half a mile up a VERY steep hill.

They wouldn't include a leccy heater unless there was a real problem.

[ianfish]

Would the heater/aircon self test function help to point to a potential cause in this case Anchs?

Can you do a test on the climate/heater to check if all is ok, mine is a bit erratic?

[Ex Tiff]

Just a thought if your thermostat is stuck open (or missing) your warm up time would be much longer.

[Davrav]

Would the heater/aircon self test function help to point to a potential cause in this case Anchs?

Can you do a test on the climate/heater to check if all is ok, mine is a bit erratic?

Yes - it involves pressing control buttons in a certain order and the system will cycle through a test routine.

I quote Anchorman here 'cos I couldn't remember the details :

'If you want to check all the servos just press and hold the "auto" and "Recirc" buttons together and the heater will enter its self check mode. Press the auto button and the heater will test cycle through all its various settings. Press the auto button again and if there are any faults it will give you a 2 digit code. If there are, let me know and I will tell you what it means but I think you will find nothing. If nothing else you will have fun watching the heater doing all its checks!'

If you want to know how it all works, fill yer boots from the attached PDF

air con _description.pdf

[anchorman]

If the thermostat is duff it won;t heat up at all.

[ianfish]

Would the heater/aircon self test function help to point to a potential cause in this case Anchs?

Can you do a test on the climate/heater to check if all is ok, mine is a bit erratic?

Yes - it involves pressing control buttons in a certain order and the system will cycle through a test routine.

I quote Anchorman here 'cos I couldn't remember the details :

'If you want to check all the servos just press and hold the "auto" and "Recirc" buttons together and the heater will enter its self check mode. Press the auto button and the heater will test cycle through all its various settings. Press the auto button again and if there are any faults it will give you a 2 digit code. If there are, let me know and I will tell you what it means but I think you will find nothing. If nothing else you will have fun watching the heater doing all its checks!'

If you want to know how it all works, fill yer boots from the attached PDF

thanks Davrav, you 're a star!

[ianfish]

Would the heater/aircon self test function help to point to a potential cause in this case Anchs?

Can you do a test on the climate/heater to check if all is ok, mine is a bit erratic?

Yes - it involves pressing control buttons in a certain order and the system will cycle through a test routine.

I quote Anchorman here 'cos I couldn't remember the details :

'If you want to check all the servos just press and hold the "auto" and "Recirc" buttons together and the heater will enter its self check mode. Press the auto button and the heater will test cycle through all its various settings. Press the auto button again and if there are any faults it will give you a 2 digit code. If there are, let me know and I will tell you what it means but I think you will find nothing. If nothing else you will have fun watching the heater doing all its checks!'

If you want to know how it all works, fill yer boots from the attached PDF

Got two codes, 21 and 24

Ian

[anchorman]

Those are normal, don't worry.

[ianfish]

Those are normal, don't worry.

41 is shown as well

Ian

[Tech01]

Just to pull a few points together in this long post...

1. Diesels are efficient; the heat of combustion goes largely into the exhaust, and the block is therefore slow to heat up. Hence the good mpg!

2. Anchs is absolutely correct: the time it takes for a diesel to really warm up (ie for the cabin heater to decently work) is NOT a function of "time on the road", but of how the car is driven. Leave home and tiddle about, sit in traffic, or head off mainly downhill, and the engine will take forever to get hot. Drive away uphill, or at speed, and things are quite different. (In the first case, the gauge reaching N (halfway) might take 45mins! In the second case, between 5 and 10.) It's simply a matter of how much fuel you are burning, and at idle or over-run, diesels consume next-to-nothing.

3. If in any doubt, replace the engine thermostat. If one of these gets stuck open, you have to wait until the whole of the cooling system gets hot before the interior heater does anything helpful, and in very low temperatures the icy blast through the radiator will prevent this from happening! If working correctly, the thermostat initially shuts off the main radiator from the engine cooling circuit, and leaves just the engine block/head, interior heater, and oil cooler/heat-exchanger (if fitted) in circuit. The water in this part of the circuit is fairly low in volume, and heats quickly. When it reaches 'thermostat opening termperature' (usually around 90degC), it opens and allows some cooler water in from the main radiator, then closes again as the temperature drops, opens again later, and cycles to maintain a high (proper working) temperature in the engine block/heater etc. A thermostat may get stuck closed (unusual, and engine usually boils), or may just get old and inefficient, or open at too low a temperature. Just replace.

4. For very cold and downhill-from-home conditions, our diesels have three PTC electrical heaters sitting in the air-intake of the cabin heater. Anchs has described how they work. On the RAV4.2 (I guess later models are the same) the PTCs come into operation if you set the rotary heater control to maximum (the last 5-10 degress of turn switch them on) when the engine cooling system is cold. As it warms up, they automatically shut off. These PTC heaters consume about 25-30A each (and there are three of them!), but the engine's idle speed will automatically rise to keep the alternator output up to cope. Using the Idle Up switch (if fitted) will achieve the same.

On my 4.2, at an outside temperature of 5degC, and driving away from home downhill, the PTCs produce useful warmth from the heater/demister after only 2 minutes.

5. In very cold weather, put the heater on Recirc (to prevent icy air coming in), use the PTCs (ie max heat), and, if neceassary, switch on the AC (to remove moisture from the air, and prevent/remove windscreen misting).

Note that if you set the AC to on, but leave the temperature control low, you can actually chill the windscreen enough, at its lower edge, to the point where mist starts forming on the outside of the screen!

If using Recirc, it is essential that the heater's pollen/dust filter is kept clean, otherwise the circulation of air inside the cabin will be significantly reduced. Don't operate without the filter in place.

____

Try the above first. If this fails to produce decent heater output, then it might be time to start looking for a blocked heater matrix, neglected or mixed-type coolant, or other nasties.

Hope helpful,

Chris

[ianfish]

Those are normal, don't worry.

I have also got 41 showing, is that the Servo motor?

[anchorman]

Don't worry too much about these codes unless there is something wrong. If for instance you turned the ignition off while it was part way through an automatic change it will show a fault code.

[ianfish]

Don't worry too much about these codes unless there is something wrong. If for instance you turned the ignition off while it was part way through an automatic change it will show a fault code.

Demister setting not working, major job methinks!

[anchorman]

Well if you have a problem thats different. It signifies the servo motor or the amplifier for the air mix servo on the passenger side.

[Rabbijon]

Hi again.Just to add to my woes I have also noticed recently the radiator fan runs fairly regularly during my 20- 25 minute commute to work. Outside air temp is rarely above 5 or 6 degrees. Is this normal as well? Or is something seriously wrong. I will check the coolant level before I return home tonight. (Should this be moved to a new thread?)

On the original issue I will give the heater test a shot as well. Still to check my cabin filter. Got time today to do all that and I will update. I've been very busy recently. Heater issue has not been so much of an issue since its been slightly warmer than previous weeks but it still takes time to get warmed up around 20 minutes.

[Big Kev]

Hi again.Just to add to my woes I have also noticed recently the radiator fan runs fairly regularly during my 20- 25 minute commute to work. Outside air temp is rarely above 5 or 6 degrees. Is this normal as well? Or is something seriously wrong. I will check the coolant level before I return home tonight. (Should this be moved to a new thread?)

On the original issue I will give the heater test a shot as well. Still to check my cabin filter. Got time today to do all that and I will update. I've been very busy recently. Heater issue has not been so much of an issue since its been slightly warmer than previous weeks but it still takes time to get warmed up around 20 minutes.

Are you ok on the cabin filter position and ease of check, Rabbi ? If not jiss shout and I will nick doon to your gaff.

Big Kev

[Rabbijon]

Yeah ok to check it cheers. Checked the coolant level and the reservoir looks empty. Opened the cap and I could not see any coolant either.

This is the troublesome part. Do I need to drain the stuff thats left or can I top it up? As for the distilled water, is that a must as well? Would tap water from the west of scotland be soft enough?

[Tech01]

Hi again.Just to add to my woes I have also noticed . . .

The more you describe, the more this sounds like a faulty/erratic/sticking thermostat: slow warm-up, erratic behaviour of cooling fans, etc. Check also for air-locks in the cooling system (use the bleed points). Personally, I'd just change the 'stat - it's cheap and easy enough - as well as bleed. At least this eliminates one obvious candidate.

If draining (or part-draining) the cooling system, remember NOT to mix antifreeze types or brands. Drain the whole lot, flush with a hosepipe, and refill with new, diluted (if necessary) with de-ionised/distilled water, NOT tapwater. Run and bleed carefully afterwards.

Let us know how you get on.

Chris

[Davrav]

You need to use a particular type of coolant Rabbi - can't remember what the spec is but the Toyota stuff is pink.

On early models the coolant used at that time was implicated in the head gasket failure issue.

Others will advise on the correct stuff.

While you're under the bonnet check to see if there is any evidence that the coolant has been spraying out of the overflow pipe just below the coolant filler cap.

[Big Kev]

You need to use a particular type of coolant Rabbi - can't remember what the spec is but the Toyota stuff is pink.

On early models the coolant used at that time was implicated in the head gasket failure issue.

Others will advise on the correct stuff.

While you're under the bonnet check to see if there is any evidence that the coolant has been spraying out of the overflow pipe just below the coolant filler cap.

........or uderneath the pull off foam plastic engine cover.....?

[anchorman]

Your fans will run every time the AC goes through the compression phase. Normal.

If they are running with the AC off and the engine is cool you might have a problem.

[Rabbijon]

Your fans will run every time the AC goes through the compression phase. Normal.

If they are running with the AC off and the engine is cool you might have a problem.

I dont have the AC running in winter.

Need to wait till daylight to check for anything from overflow.

[Rabbijon]

Hi, little update. Let toyota look at it today. They phoned back saying my water pump is leaking. £360 to replace it with genuine toyota part. Id assume that would explain the slow heat up, the low level of fluid in the coolant reservoir and the radiator fan coming on regularly. My questions. Does that sound like a rip off? How easy is it to get to the water pump to DIY it?

[anchorman]

Nope.

Most water pumps weep. It will not cure the slow warm up - forget about that. Idoubt that it will cure the fans unless it is so low that it is overheating. Has the coolant gone out of the header tank altogether?

[Rabbijon]

Hi again. Just wanna say thanks for all the advice and help you guys are giving. Its very much apprecated. Yeah the water in the tank is gone altogether. Im assuming there will be some in the radiator, but the tank is empty.