When I was on holiday I started to notice that on occasion my temperature needle would drop slightly to around 80 degrees.

Prior to that for nearly three years it has been a case of getting up to 90 and then never flinching from that point.

It only ever reads lower than 90 but no less than around 90 and most of the time it still sits dead on 90. Should I be worried or warming up the credit card?

Could be temp sensor or even thermostat.

Did the needle drop slightly when you were doing slower speeds and does it seem to take longer to warm up?

If so probably your thermostat.

Temp sensor can play up by dropping down and rising back up.Mine used to drop down to 30 them rise back up again.

Sounds just like mine, going down on the motorway and up in traffic. Quite likely the thermostat & was a bit of a pain to change situated where it is but takes about an hour tops.

Probably the thermostat, although could be the CTS. If it was going from 90 -> 100 then I would suggest a failing waterpump.

If your temp guage is going up & down randomly it's probably your CTS. If the temp goes down when you're cruising & then rises in traffic or at idle then your thermostat is probably stuck.

If you don't have access to vagcom you can use the climate control display to see the temp that the ECU is getting from the CTS. If it differs from the gauge the CTS is faulty.

Press fan slower, temp down & econ buttons at the same time, then use the colder & hotter buttons to scroll the different channels. Ch51 is the CTS reading to the ECU.

Isn't the Octy's temperature gauge just a fairly loose interpretation of the actual temperature anyway? I seem to remember hearing that it can be a good 15-20 degrees in either direction but is just normalised at 90 for the sake of providing a clear difference when something goes wrong.

Just had this problem too, the temp needle would move between 80 and 90.

It was the Coolant Temp Sensor, got a new 'green' one with clip and O ring from Euro car parts for £28, took about 10 minutes to change.

The new one took a while to get up to temp for the first time, probably because it had never been used before, but now it all works fine and the needle sits bang on 90.

I just tried the climatronic diagnostic mode and it worls, but channel 51 sits on zero - the temperature gauge is working perfectly and it shows the correct values when it's plugged into the diagnostic kit, so no idea what's happening there

Isn't the Octy's temperature gauge just a fairly loose interpretation of the actual temperature anyway? I seem to remember hearing that it can be a good 15-20 degrees in either direction but is just normalised at 90 for the sake of providing a clear difference when something goes wrong.

Yeah, I doubt it would be that precise to stay on 90 at all times.

Accessing On-Board Diagnostic codes Press and hold the recirculation button. Then press the manual flow control up arrow. You should see a 1c. Press the temperature up ("+") or down ("-") buttons to select a code number. Then press the recirculation button again. The value should display. Press the temperature up or down button again to display another code.

Thanks for all the help

I had a new temperature sensor about two years ago. In that case the gauge was fine but I had a CEL light on.

There doesn't seem to be much reasoning about when it decides to drop. The first time I noticed it though was the first cool night after 10 days of driving the car in 30'C+ temps so maybe that was enough to finish it off?

I'll try the climatronic trick tomorrow

Mine did this when the thermostat was borked.

When the CTS was broke it used to drop like stone then shoot back up again, if it your stat then you will be losing mpg as the ecu will be all to ****

If your temp guage is going up & down randomly it's probably your CTS. If the temp goes down when you're cruising & then rises in traffic or at idle then your thermostat is probably stuck.

If you don't have access to vagcom you can use the climate control display to see the temp that the ECU is getting from the CTS. If it differs from the gauge the CTS is faulty.

Press fan slower, temp down & econ buttons at the same time, then use the colder & hotter buttons to scroll the different channels. Ch51 is the CTS reading to the ECU.

Is there a link to a list of all the info available via this method? This sounds like a really useful tool.

Thanks,

Martin

Is there a link to a list of all the info available via this method? This sounds like a really useful tool.

Thanks,

Martin

Put this into google VW Secret Codes Provided by ComputerAnything.co.uk

If it doesn't work P.M. me & I'll send you a pdf with full list.

Found this which has a slightly different list of code meanings, will test it out tonight to see if it's valid.

http://pics.tdiclub.com/data/517/Climatronic_Self_Diagnostics.pdf

Now that version of the errors seems to be more in line with my climatronic, and might explain why my channel 51 reads 0 instead of the engine temperature. I'll try that later, nice find

Found this which has a slightly different list of code meanings, will test it out tonight to see if it's valid.

http://pics.tdiclub....Diagnostics.pdf

I've run through this tonight. A much closer match for my climatronic but not 100%. Channel 45 is supposed to be "Motor temp" but my car reads -99C?

So it seems to be a collection of interesting (but not much use) random bits&bobs.

On 12.08.2010 at 20:06, 2SkodaFamily said:

I've run through this tonight. A much closer match for my climatronic but not 100%. Channel 45 is supposed to be "Motor temp" but my car reads -99C?

So it seems to be a collection of interesting (but not much use) random bits&bobs.

 

Same problem. Any opinions ?

On 14/03/2017 at 07:24, gabi_cta said:

 

Same problem. Any opinions ?

I'm assuming you have the mk1 Octavia. If your temp gauge isn't sitting in the middle then almost certainly this is due to a faulty coolant temp sensor, a common fault. That's what I ended up doing with mine. Make sure you buy a genuine VAG part though, and not a cheap alternative. The cheap ones fail. Also get a new one not one from a breaker.

My temp sensor went but when that happens it's more dramatic and up and down randamlly.   I'd say thermostat is the issue.  I had the same issue it sits at one lower temp 70 to 80c only gets to 90c in heavy traffic.   

Same as above, when i got mine i had a stat handy as they always need doing. with it sitting low is stat.

 

If it flickers off and on then its the switch

If it drops on hill descents or coasting then I'd say stat as well.