Temp (guage) v's Air Con - help reqd?

[SixDegrees]

Ok, so since I bought the car 5 weeks ago the temp has risen to 90 degs and sat there once the car has warmed up... as expected.

Now, that the outside temp as dropped (11 degs today) I turned the AC up to 22 degs to get a wee bit heat in the car (old bones an all that).

Car took ages to get the neddle to move and didn't make it to 90. So, off with the AC (heat) and it slowly rose to 90, back on with the CA (22 degs) and in about 2-3 mins it was down to the 1st mark before 90.

So, I did this a few more times while driving home. Each time the AC was on and reqd to blow warm air the neddle started to drop and you could actually see it dropping.

I has never gone above 90 even back when we had temps like 24 / 25.

I'd have though that even if the car was reqd to blow warm / hot air into the cabin the electonics would stop cooling the engine to maintain a consistent 90 degs - operating temp!

Any ideas what I should look at; thermostat, temp sensor (where is it), other?

I've not noticed any drop in performance or other similar issues that would indicate the car isn't performing well.

Thanks

 

[A3Monster]

Just a thought. My temp guage kept dropping and acting weird and it turned out to be the dash cluster. The fuel guage was already faulty.

Your problem sounds oddly familiar - I kept thinking it was losing temp or something.

Hope this is food for though, might not be this though, just saying!

 

[Pinola]

Mine does the same SixDegrees dont know if it's right

 

[Dani_B19]

No it isnt right it should sit at 90 regardless of what you do. Sounds like you need a new thermostat. Have a look been covered loads.

 

[SixDegrees]

No it isnt right it should sit at 90 regardless of what you do. Sounds like you need a new thermostat. Have a look been covered loads.

Aye, not right. Guage looks fine until hot air is required and then it wanders so I'll start with the theromstat.

Did a wee search and have found out what I need to do, looks pretty simple and having done head gaskets, water pumps and the like in the past this looks like its in the easy end of the sacle... all bar the bit about the lower bolt!

Anyway, bruv has a garage of pretty much every tool in the book (MX / motor bike business) so off to VW to get a 'stat and get it changed over.

Thanks for the info / links

 

[Broken Byzan]

Under the inlet manifold sort of behind the alternator. It's a nuscence (sp) to get to but perfectly do able as a diy

 

[S3KO4]

Any changes? as I have similar issues with my s3 and my dad's a6 1.8t, I am sure if the temp sits lower than 90C then you will loose power and it consumes more petrol as its not runing effeciantly. please let us know how you got on.