Cooling Climatic on a long journey

[Tups1974]

Hi All,

After some advice if this is the norm or not, I've just done a trip from the south coast to Newcastle over the weekend and back again. We started off with the heater set on 22 degrees and speed one, but after a few hours on the road the inside of the car started to feel cold so we turned up the temp a bit more and then a bit more and so on until it was almost 26 degrees and the car still felt cold, turn to the heat up to max and with a few mins its too hot. But when we stopped at the services for a break and then resumed ther journey 22 degrees was fine again for another few hours until we had the same issues again.

Any ideas if there is the norm or I might have an issue?

Regards, Bill

[Teflon]

I'm assuing that if you are able to set 22 degrees, you have the two zone climate control?

Don't bother with the speed setting. Select temperature and put it on auto. Don't hit the Econ button, leave the system to do its thing. The climate control should do the rest and keep you at a constant temperature. If not, then yes, maybe you have a problem.

[Tups1974]

Thanks for the reply, but its an SE with the standard climatic system of three dials, 1st dial set temp, 2nd dial select speed, 3rd dial selects direction, Air con permanntly on unless eco switched pressed - wish the car did have dual climate control...

[billythetidd]

That's just aircon, not climatic.

[gingernut352000]

I have climatic and have a same sort of problem was advised on here that it could be a flapper motor but have been out of work so not got it done. Back in work now so may get garage to investigate next time it's in but I think the motor was in the region of £90 plus a couple of hours labour +vat. Some one also suggested that it coudl be a temp sensor in the heater box.

I am a layman to car repairs.

[Tups1974]

That's just aircon, not climatic.

Nop it definately says Climatic on the middle control - plus the hand book talks about three set ups available: Air Con, Climatic & Climate Control

[Tups1974]

I have climatic and have a same sort of problem was advised on here that it could be a flapper motor but have been out of work so not got it done. Back in work now so may get garage to investigate next time it's in but I think the motor was in the region of £90 plus a couple of hours labour +vat. Some one also suggested that it coudl be a temp sensor in the heater box.

I am a layman to car repairs.

Cheers, I think that its off VW this week for a look!

[patomlin76]

Climatic is a form of climate control, just not fully automatic. When you get it working properly again, you will notice that on hot days 22 will cool the car to approximately that temperature, whereas on cold winter mornings it will pump out warm air to raise the temperature.

Having said that I would have liked the Climatronic if I'd known about it at the time of buying, it just wasn't a dealbreaker.

[manity]

will be interested in how this works out have exactly same issue with mine dual climatic aswell.

[Tups1974]

Well the car is booked in for Thursday and even the service depart at my local VW agent have admitted if the fault code scan comes back clear it will be an interesting one....

The car was fine this morning on short runs, checked the oil, water levels etc all fine and on the max level, when the car is up to temp, the temp gauage sits at 90 degrees and does not move.

[manity]

same here short runs are no problem it only happen`s on longer runs. i have VCDS and no fault codes appear with that.

[gingernut352000]

Concur short journey & town OK its when u open it up on the motorway mone goes hey wire.

Please post the garage diagnosis etc.

[Tups1974]

Update: Well local VW dealer can not find a fault but they have replaced a sensor that has caused and fixed this issue in other cases but my situation is still the same - it is as if the Air con is over cooling the car - the case has now been referred to VW Tech for advice.

[Lincs Vagcom]

Sounds like the flap to divert air through heater matrix is failing to me.

[gingernut352000]

Do you know what sensor was replaced?
Thanks
Adrian

[Tups1974]

Not sure on the part number as I've not paid for the work yet despite getting my car back last week, all I do know is that it is a sensor that fits into the plastic heater ductwork behind the dash!

Without any fault codes and no real experince of this issue before, my local dealer has been waiting for further guidance from VW, they are now talking about changing another sensor on the engine side of things, the motor flap (as this clicks a little when starting up) and also the climate control ECU which will be about another £300 worth of work on top of the £150 already on the slate, but the ops manager is going to look at the overall labour as some of the removal work and refitting work would have been duplicated, I'm due for an update on things tomorrow

[Tups1974]

Well got the car back last night after having a new ECU fitted for the heating system (flap motors were fine) which seems to have cured my issue - however the new ECU (heater control unit) no longer has the ECON button or the words CLIMATIC on the middle control - so I am now wondering if the dealer has fitted the wrong part as before the aircon was permanently on and switched off with the ECON, now I have to switch on the aircon using the AC button - any ideas if the orginal part has been updated in any way?

[patomlin76]

My climatic model does have the econ button (so have to switch off air-con), but does not have the words climatic on the middle control.Must be a few versions of this going around...

[hartry]

My old '08 with climatic had an AC button and didn't have the word climatic printed on it, just like your new part Tups.

[manity]

is the heater ecu built into the control unit?

[Tups1974]

is the heater ecu built into the control unit?

Yes the ECU is built into the control unit - however after a long run today it seems that the sensor that is located in drivers side air vent and the new ECU/conrols that has been fitted has not cured the issue at all........ now getting really fed up with the car! bet my bottom dollar that in the fix is something so simple! i'm even now starting to wonder if there could be an issue with the matrix or thermostat

[Tups1974]

My old '08 with climatic had an AC button and didn't have the word climatic printed on it, just like your new part Tups.

Thanks, my VW dealer says that the control unit /ECU has been updated five times since 2006, and the reason why they when from the ECON to AC button is that the ECON button confussed too many people??? I am also wondering if fuel economy and emissions had anything to do with this decision as well? as the air con is no longer on all the time!

[Tups1974]

Just done a trip up to the Midlands and its confirmed what I had thought the replacement ECU and sensor has made no difference at all, the car is booked back in next week for more investigation work. The flap motor is making no noise, and this passed the measured block test the dealer carried out. After todays run, I firmly believe that external air flow is getting into the cabin as on our trip up the colder the external temp got the colder the inside of the car got, and at 1.5 degrees my car was set to 26 degrees jsut to keep us warm.

If any forum users could provide me with a comparsion on the following set up I would be grateful, as I'm not back home til monday and therefore can not use the wifes car and my is booked in for Tuesday next week.

At Motorway speeds, heat set to 22, blower on speed 1 and direction on windcreen/feet and all of the four dash vents on the car open
* I get cold air coming out the the two side dash vents and warmish air directed on the feet and windscreen

Same set up as above but this time with the blower off - I get cold air out of all vents - windscreen, feet & side dash vents

Is what my car doing the norm with anyone else?

[Tups1974]

Back to the dealers yeterday, another ECU fitted a few sensors changed and the car seems to be working okay inside a workshop - but VW UK suggested changing the ECU again, so today new ECU was fitted and now the latest news is that there is now officially some kind of problem depsite the ECU and sensors changed the car thinks that the inside temp is at least 28-30 degrees hence why the aircon system is trying to cool down the car, even when the temp is set to 22 degress or lower so back over to VW tech for help.

Interesting enough we also discovered last night that my wife's 08 Passat estate does the same thing, goes into "chil mode" after about an hour of being on the road and then resets itself when the engine has been turned off.

Talking to a few other people I know they say the same thing is happening in their cars............ perhaps a software fault? who knows

[Tups1974]

Now my local dealer who has been very helpful in this matter has described this issue as " A characteristic of the car" because whilst in the work shop it all works fine, but as proven yesterday (to the dealership) that once the car has down the motorway for about 45 mins the car will blow out cold air even when set to 25 degrees - so now awaiting further guidence from VW tech although I am starting to lose faith in this.

I am wondering based upon some of the comments made by the guys working on the car that this issue is caused by the sensor in the heater control (little black button shape found above the AC / Econ button) being heated by the backlighting of the surounding switches and therefore over a lenght of time heats up so much that its gives the heater ECU a false reading of the temp inside the car, hense why the car blows out cold air. I'm gonna try out my theory by doing a long distance drive during the day without using the lights (if I can do so safety), it will be intereting to see if the heater works normally with the lights off.

Plus I've also noticed with the newer models that this sensor is still located in the heater control panel but not near any light / heat source..........

[manity]

i dont think it can be the heating up of temp switch, ive had this problem with mine for awhile now during the summer after about an hour of driving in warm temps outside my heater control just shuts the vents so no air con comes into the car so gets quite warm in car. and in winter the same after an hour vents close again and temp in car drops. i know its the vents closing because if you turn the fans up you can hear them running but no airflow. ive found if you turn the heating off using center on/off button then give it 5 minutes then turn it back on it resets itself for another hour. i dont do many long trips so ive learned to live with it.

[Drash]

Hi all,
Just noticed this thread - our car does this/pretty much has always done this for at least the last few years. Only diff we've got Climatronic (dual zone) and it only really affects the passenger side.
Drives the wife crazy. She found turning it off for a few mins resets it and works fine until it does it again. Seems to block all the vents - stuffs trying - cold in Summer or hot in Winter but it can't get through as some central vent control seems shut off. Did seem to get better for a while after we had a new radiator fitted, which I think entailed regassing the aircon. Just another B6 quirk - wouldn't buy another after the list of stuff we've had to replace. Thankfully not a daily driver anymore so I can't be ars*d hassling the garage. They've been good but they're up against it with the sh*te VW are putting out these days.

[mrjmanik]

i drive long distance regularly and my b6 does the same thing i find adjusting the temp on the dial seems to work
but it is annoying when driving along to find the car not heating up when it's cold outside
haven't tried it when it's hot outside to see hat the aircon does
let us know if anything is answered about this

[Tups1974]

VWUK are looking into this as the dealer is starting to draw a blank, they changed the evapourator sensor on Thursday last week, and I driving around everywhere with a digital thermometer recording temperatures, settings etc

After covering 700 miles this weekend (since the sensor chnage) I am finding that I have a bit better heat control but the car will heat up to the setting and then fall back by about 2.5 degrees, this process continues right up until I run out of tremperate range on the dial.

Will post more news when I get some.

[mrjmanik]

anymore news
my temp in the car seems to do the same

[Tups1974]

no more news still awiting VWUK to finish looking into the matter, perhaps you should call them and lodge an issue as well, the more that get lodged with them, then perhaps the more effort will be made into getting a solution

[Tups1974]

Had an update call from VWUK today just to say that they have no furthers ideas at present on how to deal with the issue that I am experincing and without the dealer willing to undertake a 4 hour test drive (poss due to cost) there is not much more that they can do, so it looks like this will be another one of those things to add to the B6 list of faults.

Interesting enough had a chat with a mechic mate of mine who said that the Ford Monedo (99-06 shape) had a bit of rep for this sort of thing, cooling heating and not quite getting upto temp which most garages put down to a over efficient engine running cool, when in fact its a sign that the thermostat that controls the oil flow to the oil cooler on its way out..

Any ideas if the Passat has this set up?

[Tups1974]

Back in again today having the thermostat replaced to see how thats goes, just in case its a slow reacting thermostat...........

[Tups1974]

Hopefully Good News and a Result!!!


I had the car looked at today, with a view to replacing the thermostat to see what affect this would have on this issue by my local VW Indy.

Well I had a telephone call this afternoon with an update: he said that after running some temperature tests on the car it appeared that the car was being cooled by the outside air temp, hence why the issue was getting worst on long journeys rather than short ones. After an 80 min drive the cartemp display was reading 90 degrees, but the actual temp was 54 degrees at the radiator, 58 degrees on the engine block water pipes and 52 degrees at the heater matrix.

Upon further investigation it seems that the thermostat was staying slightly open hence why the heater system could not hold temp as the radiatorwas cooling the whole water system. So a bit more investigation and it seems that the thermostat was working fine the issue was being caused by the electric sensor/switch with heater (like a kettle element) in the thermostat housing that controls the thermostat not working correctly. But this fault was not being picked up by the VAG diagnosis software, (perhaps someone like Martin 810 could explain this further)

Upshot of it all new thermostat, new thermostat housing complete with electric switch/sensor and the issue now seems sorted because at 22 degrees the car is a lovely place to be so fingers crossed to see how the car performs over the next few weeks.

Turns out over the last 12 months, this Indy has done 6 VW Passat's with the same issue and two Audi A4’s

Why the main VW dealer could not fault find this is beyond me, perhaps it’s a case of old school mechanics v modern software and PC saying no……

[manity]

sounds good if its sorted the problem. have this problem myself and have been keeping an eye on your posts. dont supose you have the part numbers of the thermostat and housing and switch. also prices of the said items would be great will do it to mine if all works out ok with yours. will be a few on help sending thanks your way for your posts...:You_Rock_

[gingernut352000]

Sounds promissing as per manity it looking forward to progress report and part numbers and costs etc.

[Tups1974]

TPS Part Numbers – sorry only have these rather than the VW numbers as the Indy went to TPS for the parts

03G121113 –Thermostat - £12.36 + VAT

038121119B –Washer - £2.08 + VAT

G012A8GM1 –Coolant - £8.25 + VAT per 1.5 litre bottle (Two Bottles used)

03L121121A –Thermostat Housing - £6.57 + VAT

06A919501A–Coolant Sensor - £29.50 + VAT

N90316802 –Coolant Sensor O-Ring - £1.06 + VAT

Plus two hours labour for a drain down, flush through and refitting, apparently the alternator has to come off to get access to the thermostat housing cost £80



Also a point of interest the parts changed by VW dealer with the assiatnce of VWUK prior to the indy solving the issue.

1K0820047JNWHS Heater control panel with control unit

1K0907543F Evaporator Sensor

Plus the dealer substituted various air vent sensors aswell, however they failed to improve the issue so they were swapped back to the original parts.

Hope this helps,

Bill

[Drash]

So harking back to olden day cars (the kind I tinkered with before they got too complicated) net effect is same as thermostat being open when it should be closed, which means engine running too cool, taking too long to warm up which means increased fuel consumption and smoking. Am I right? Have you noticed any change in fuel consumption? Seems this is the only diagnosis tool left to non-laptop equipped users these days, apart from a pair of keen eyes/ears!

[Tups1974]

I thought that the fuel consumption was always very good for a diesel auto, I get on average around 48mpg, and there was a little smoke from time to time but mainly when you it a good burn up the sliproad, but I just accepted this a carbon build up due to town driving. But over the last few weeks the car was taking longer to warm up comapred to the norm that I have been used to - so this is why I wanted the thermostat changed (if anything just to rule it out) and as my local VW dealer said that there was no fault with it, I took it to an Indy for a look.....

[gazza007]

Hi,I was wondering if the heating is still behaving itself? I going to spend a few quid on the car at an Indy next week in Scotland as Passat has been a great workhorse so going to keep for a few more years.I think I will have this looked at along with;EBP motors, been noisy for a while with the odd fault which cleared but actually got stuck on last week managed to release so driving round without handbrake but being DSG can leave OK in Park, just need to avoid hills.NSF CV boot has gone, OSF will probably need doing too.Interim service dueI'll live with the noisy castlelated Kuhmo's and then replace all 4 when needed with another brand possibly Hankooks, maybe get the alignment checked too.Front Discs and pads/ fluid were done a few weeks ago, £280 all in but can't complain after 75k, rears were fine.I'm sure something else will pop up but going to be expensive job all in, I hope its just the motors and not the calipers too.

[Tups1974]

Hi the car seems to be fine - have no issues with it now - hope this helps3

[gazza007]

Thanks Tups,I'm curious to know what part the cooling sensor plays.My understanding is that as the coolant reaches 90c the thermostat opens, the sensor reads the water temp and controls the cooling fan on the radiator or does it play a bigger part such as controlling the heater matrix?Perhapms Martin or others may know more before I go to more expense than I need

[Tups1974]

Not 100% sure myself, but the Indy changed it beacuse after a long run, the temp gauage in the car sat at the 90 mark but the water temp in the pipes and engine block was about 56 degress and lows on the 50's rad side

[JustinM3]

Sorry to drag this up, but was an interesting read.
I don't fancy one of these after years of running way too cold, can't see the engines lasting like the 1.9's have/do :(

[Quatrelle]

I wonder if anyone has had a reading of anything other than 90 deg once the engine is hot.

My old MG has a thermostat, electric fan etc and the temp gauge wanders around from 'normal' depending on how hard the engine is working.

I get the impression that the Passat's temp gauge just tells me what it thinks I'd like to see.

[JustinM3]

I think most cars have a weighted gauge to keep it stuck to 90, as you say temp does vary by a couple degrees as the 'stat does it's thing.

[martin1810]

I wonder if anyone has had a reading of anything other than 90 deg once the engine is hot.

My old MG has a thermostat, electric fan etc and the temp gauge wanders around from 'normal' depending on how hard the engine is working.

I get the impression that the Passat's temp gauge just tells me what it thinks I'd like to see.

It will show 90 degrees as long as temp is within the range 80-110 degrees. roughly. VCDS gives the true answer, the guage doesn't.