Coolant temperature not hitting 90 degrees

[spartacus 68]

Driving over the last few days in my B8 Allroad (177PS), noticed that the car takes forever to come up to temperature. Granted it's cold, but wonder if it's coolant temperature sensor?

I scanned car a week or so ago after a full service and nothing on VCDS to indicate a fault. Audi main dealer fitted timing belt last Autumn and fitted new water-pump too.

Temperature wise in the car - the blowers are blowing hot air (maybe not as hot as it should be on HI), so thermostat must be allowing coolant to circulate?

Ran home last night, put heaters on in car and temperature hit 90. This morning, struggled to get above 50 degrees.

Any suggestions as to where to start?

 

[KrisKrk]

Many members and VAG owners complain about it a lot. Especially (and looks like only) in the winter.

I have 2.0 A6 2010 and it does the same. It is even harder to reach 90 even after 6-7 mile drive, if temperatures are much lower, below 0.
If I start up the car with heaters on, it will not reach anywhere near 70, not to mention 90. If heaters are off and drive on high revs, gear lower than should, It will reach 90 no problem. As soon as I put heaters on, It drops down, despite still driving.

I had stat replaced last year February so doubt it would stick after a year.

You are right saying, heaters not blowing hot air as they should but still hot air is blown. Coolant is circulating so it may be something to do with temp sensor.
Maybe computer thinks, if you switch the heaters on, it will be too hot and prevents it by opening the stat to allow coolant circulation?

No expert here but it would be a good start. See if temp sensor shows anything in vcds (you already mentioned all is fine) and maybe adjust the coolant flow temp trigger?

Another thought, Black Cab drivers tend to cover their radiators/grilles with cardboard, during winter. That should block air flow to cool the radiator and there fore, bring up the temperature. Not sure how would that work in practice but I considered it doing. Just don't want to mess a car, if something went wrong.

 

[gary_a4_quattro]

As many others have mentioned, achieving the usual 90 deg C running temperature over a short-ish commute to work or similar is something I've experienced in this current weather condition.
I've put it down to a combination of things; much lower than usual ambient temperatures which havent risen above 0 deg C for the last 5 days or so, coupled with the flat out use of the car heating. The heater matrix very well may be able to dissipate enough heat in an attempt to take sub-zero external air upto the requested 20 deg + we'd like to enjoy in the car, coupled with the natural engine heat dissipated into the surrounding air, thus not actually achieving a coolant temperature point where the stat would normally start to open fully.

 

[Retroman]

I notice it when the outside temp gets below 10C. Many TDI owners say similar

 

[Jon B]

Completely normal on Audi TDI. I asked local specialist about it. Think the manual even says it’s normal.

 

[spartacus 68]

Thanks for that. Will put my spanners away.

 

[Retroman]

Been a bit milder in Somerset the last couple of days and on a couple of longer runs I noticed mine is back to 90C on the temp gauge.

 

[Marky007]

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