Avant4Adam

Have to believe that both are likely non-issues in most circumstances at this point with the level of engineering put into Audi's TDI engines. Get in and drive it.

AudioBear

And diesels are notorious for lasting hundreds of thousands of kilometers. And gasoline dissolves the oil off cylinder walls. And I don't want my A6 TDI to last too long anyway because I want a new car every 3 or 4 years.

I don't understand the slow heating or the temperature dropping back--maybe a thermostat is opening prematurely or wide open at too low a temp. My TDI takes 6-7 minutes to reach normal temp and about 2 mins to be pumping warm air to the passengers. I think it's time for a trip to the dealer and don't accept that "it's normal."

Coolieman1220

Let it idle on a cold day. See how long it takes to warm up to normal operating temperature, if it gets there at all. Diesels are extremely thermally efficient especially at idle. They don't give off much waste heat and the only real way to warm it up is to just drive it.

In the settings, there's one for an external heater. Our vehicles are fitted with a ceramic heater that turns on that can provide heat to passengers before the engine warms up. I find it gives heat quicker than my 2.0t ever did. I also find the diesel, once warm, stays warmer longer than the 2.0t

gojones

My 2015 TDI warmup time is slightly longer than my Chevy Truck. However it is not that noticeable and temp stays at halfway. Something doesn't sound just right for it to fluctuate much. My gauge is steady after warmup. Use your seat warmers also.

DimaA6_ABC_Kiev

I have the same in both 2.0TDIs, so as long as you fill comfortably driving it I would not recognize this as an issue.

janB7

My temperature gauge only drops and fluctuates when the air temperature is below 15 F and gets worse the colder it is. Above 15 F it warms up slowly but without any noticeable fluctuation of the needle. At 0 F or lower it will come up to 1/4 mark and then sink almost all the way back down to starting point. It will do 2 or 3 of these fluctuations before going to the mid "normal" mark which is reached after 20 or 30 minutes. Car went into dealer a week ago and mechanic said he observed this too and changed a temperature sensor which made no change. He says he has not seen enough TDI's to know if it was normal or not. He was checking with Audi and I have not heard back.

Can anyone confirm that at these temperatures their TDI definitely does not do this?

tjacopi

The problem is the location of the car.....its in a place that gets 15 F or colder :-).

brutus23079

I can confirm it, but my opinion means little. If your dealer is playing the IDK card (although swapping sensors was a worthy shot), you might want to ping some northern tier VW/Audi service departments. Short of that long shot, you're at the mercy of the corporate-Audi answer. If nothing else, at least you have it documented with Audi if something happens later...

perlfather

I do not know the amount of energy waisted as excess heat for diesel engines, however for gasoline engines about 70% of energy is converted into heat - so less than 30% is used to move the car forward.

janB7

My gauge is relatively steady after warm up. It is at the colder temperatures during the warm up that it fluctuates. Do you drive in an area that gets that cold? If so, does your gauge fluctuate during warm up?