CABIN HEATER NOT WORKING!

would be good if you could monitor the temp that the ECU is seeing whilst the gauge it going up and down

I agree with Steve B these are classic thermostat failure symptoms, but the last few weeks have been very cold outside temps and asa result my TDI as not got past 70 Deg C on the gauge on my commute to/from work which is 7.5 miles on all B roads.
When it is very cold outside and the cabin heater is on full, unless the engine is above around 2000 RPM it simply does not generate enough waist heat to heat up the cabin, hence the temp falls away.
The Webasto helps greatly, but at the expense of burning extra diesel
All I am saying is that it may not be the thermostat, but simply slow driving and cold ambient temps

My own A2 will hit 90Deg on the gauge after about 4 miles of motorway running at 70MPH, but then pull off the motorway and drive through towns etc without the webesto off and it will drop on the gauge quite quickly when it is only 1 or 2 deg outside
 
Birchall said:
Forgive me if you have already done this but they are the classic symptoms of a thermostat failure. Did you have it replaced??

If you did then it may be that the new one is faulty. But as I say these latest symptoms indicate a failed thermostat.

Steve B
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Hi Steve.

I can answer this. The thermostat was replaced (post#32), but I do note originally the garage saw no point in thermostat replacement and a cynic might wonder ............ or just bad luck with a faulty new part.

Take Paul's point about cold weather, (my FSI is taking much longer to reach 90), but surely after a what sounds like at least 30 minutes of motorway a TDI should reach 90?

Like a detective story this, and the ending will be revealed when Au2ro reports back on his monitoring of the temperature received by the ECU.

Andy
 
Even in the cold weather you should still see 90 on the gauge after a reasonable time.
A car that runs below that temperature would soon have problems, so cars running in Norway etc. would I expect be able to reach 90 unless it is extreme cold.
But in the UK 90 should be achievable.

Steve B
 
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Birchall said:
Even in the cold weather you should still see 90 on the gauge after a reasonable time.
A car that runs below that temperature would soon have problems, so cars running in Norway etc. would I expect be able to reach 90 unless it is extreme cold.
But in the UK 90 should be achievable.

Steve B
Click to expand...

Just to clear things up a little. If my tdi is on the motorway even in 0deg c ambient outside temp the gauge hits 90 and stays there providing the road speed is above 50 mph with the cabin heater on full hot. However as soon as you come off the motorway or get stuck in traffic and are doing less than about 20 mph then the gauge will drop back from 90 deg C
If the webasto is turned off (econ lite up) then it will go down to just over 60 deg C. If the webasto is on then you here it kick in and the temp is maintained around the 80 deg C mark


Sent from my iPhone using Tapatalk
 
Well, that's it fixed now.

Just to clarify, the first garage that I asked to change the thermostat while they were changing the alternator said that the symptoms did not require a thermostat replacement. That was before the fan went.

The second garage that I asked to fix the heating problem said that they had removed the thermostat, hot water tested it, and it tested OK so they replaced it i.e. the put the old thermostat back in.

Sorry if I was not clear enough about this earlier.

I got an OBD2 scanner that sits on the steering column in front of the dash and, during this weeks commute, this confirmed that the temperature gauge on the dash is now working OK. There is a lag on the temperature gauge on the dash as the OBD2 scanner gets up to around 75 degrees before the gauge lifts off 60 degrees but after that the gauge and the scanner kept pace quite closely. Before installing a new thermostat the water temperature never got past 80 degrees and it took a while to reach a stable 80 degrees as it would fluctuate depending on traffic conditions, even on the motorway it was slow going some days because of the weather.

So I decided to fit a new thermostat myself, I bought it from ebay.
https://www.ebay.co.uk/itm/Meyle-Germany-Thermostat-Coolant-with-seal-100-121-0048/291685546008?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I tried all the tools that I had that I thought would fit to get the old thermostat out last weekend but none of them would get to the bottom bolt so I looked on ebay for a suitable tool.
I got this one https://www.ebay.co.uk/itm/Trident-T264350-3in1-Mini-Ratchet-10mm-Inc-1-4-Dr-Socket-Adaptor-Bit-Adaptor/160993259617?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
as it came with both a 1/4" Socket Adaptor & Bit Adaptor.
It worked well with a 10mm socket that I had but the hex bit that I had was just too long for it to fit. It took a lot of fiddling about to get it in place and turn the bolt but the ratchet was fine enough and the handle small enough to turn several clicks each time it returned between the obstructions. Once the bolt was loose I had to hold the back of the socket adaptor with some needle nose pliers for the ratchet to work but once the bolt was sufficiently protruding I managed to release it with my fingers. I had a magnetic pick up tool ready to catch the bolt as although I could turn it with my fingers I could not hold it and pull it out with my fingers.
I did not take the hose off the thermostat housing as the hose was flexible enough to just move it out of the way.
The old thermostat was a little rusty but was not visibly broken. I guess they just loose their springiness after a while and don't open and close at the correct temperatures?
Very little coolant seemed to come out but in the end I had to top up with just under 2 litres of coolant that I had ready for the job.

I topped up the expansion tank and then I ran the engine for a while and revved it a little, squeezed the hoses and topped up some more.
I took it for a short drive but it did not come up to temperature before I thought I had better check for leaks and top up again.
I checked it after going to a shop and when I came back I saw a puddle under the engine, for a moment I thought I had a leak but realised that the puddle must have been there when I parked - I just did not think to check before going to the shop. Doh. It was not leaking.
I topped it up some more and went for a spin, only a for few miles but I got up to 60mph for a few minutes before the gauge and OBD2 scanner showed it creeping up to 90 degrees and once it got there it stayed there. When I got back to the house I left it running and it stayed at 90 degrees. No leaks and no more topping up was necessary.
 
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Oh I forgot to link to the scanner I got, it was this one:-
https://www.amazon.co.uk/gp/product/B01HET7ANE/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
It did the job, and was better than risking watching a phone app while driving.
It seems to monitor the temperature OK, but I think that the speed monitor would need calibrating as it does not seem to register the correct speed out of the box.
It is not wireless either, you need to loop the cable behind the lower panel in the foot-well to avoid a trailing cable in the foot-well.
 
Good news then. Can I take it everything is working as it should and all your problems are sorted? - Andy
 
Birchall said:
Even in the cold weather you should still see 90 on the gauge after a reasonable time.
A car that runs below that temperature would soon have problems, so cars running in Norway etc. would I expect be able to reach 90 unless it is extreme cold.
But in the UK 90 should be achievable.

Steve B
Click to expand...

I can confirm that at least 2x 1.4TDI AMF engine code, both reach 90 degC within 13-14 min of driving up to -25 / 30 without any modification.
Over here it is quite common to partly cover the radiator or reduce intake air area to faster be able to reach correct engine temp (90) faster.

If you remove the skid plate (the plastic plate underneath the engine) you will hardly reach 75 degC when the outdoor temp is -5 or lower.
Even if one of the sideplates are missing on the skidplate you will notice extended heatup time.

I use electrical engine block heater on mine so they are 55 when I turn the key wintertime. This reduce wear, fuel consumption and most important: hot air on the icy windows after 10 sec.... The brand I use is Defa. Can definitively be recommended :)

dieselfan
 
audifan said:
@Au2ro you didn't see my post fastest-way-to-replace-water-thermostat-without-removing-alternator.
Click to expand...
Yes, I saw it but did not have a suitable ratchet ring spanner that I could have inserted a 5mm bit into that would fit it like you must have had. The one I bought was ideal for use with the adaptor for a 10mm socket that I had rather than the adaptor for a 5mm bit, though if I had a shorter 5mm bit that would have done just as good a job.
I really did not think it necessary to remove the spring clip that secures the hose to the thermostat housing either as it was easy enough to just move the housing and hose out of the way and back again once the thermostat with new ring was inserted. I probably would have spent extra time trying to get the spring clip released.
I am sure that if it was something that had to be done regularly to get the hang of it either method would have been just as quick.
 
dieselfan said:
I can confirm that at least 2x 1.4TDI AMF engine code, both reach 90 degC within 13-14 min of driving up to -25 / 30 without any modification.
Over here it is quite common to partly cover the radiator or reduce intake air area to faster be able to reach correct engine temp (90) faster.

If you remove the skid plate (the plastic plate underneath the engine) you will hardly reach 75 degC when the outdoor temp is -5 or lower.
Even if one of the sideplates are missing on the skidplate you will notice extended heatup time.

I use electrical engine block heater on mine so they are 55 when I turn the key wintertime. This reduce wear, fuel consumption and most important: hot air on the icy windows after 10 sec.... The brand I use is Defa. Can definitively be recommended :)

dieselfan
Click to expand...

Dieselfan,

Any more info on the block heater - does it need the sump modifying or is it a plug and play diy job?

Simon.
 
Hi Simon,
You can via this link see what Defa recommend today: http://old.defa.com/en/automotive/warmup/find_your_engine_heater/
I was supprized to see that they for the AMF have changed to hose fitted heater, I will check with my dealer.
Mine have block heater fitted to the hole for one of the frost plugs in the block. They are old, probably fitted at 0km...

Not my intention to preach a brand over others. There are several on the marked, Calix is one of them.

I will try to read off my part number and see if the heater I have still is in production.
 
I did a search on this Forum and did not find much related to engine heating systems. Maybe a topic for a separate thread ?

On the picture below you can see some of the advantages that this system can bring to your car.. battery charging every time you connect, you can program the heater to start 1h before you plan to go to work, or you can communicate with your smart phone....

cal1762461_large_3.jpg
 
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