Hello forum,

My 2000 A6 2.7t seems to run hot when the outside temp goes over 95 degrees. When I run the air conditioner and come to a stop, the gauge moves past center to the next marking on the temp gauge. The dealer ship stuck me for $1850 to replace the coolant tank and hoses. Problem persist. Than they said the Audi has a complicated cooling system involving four fans, and two of my fans weren't running...gave me an insane quote for fan modulators. Took it else where to a shop who (claimed) he fixed the fans.

Washington DC was hot yesterday..99 degrees and my gauge started to creep again...so If I ever get caught in a traffic jam, I will be in big trouble.

Any suggestions besides taking it back to dealer ship?

 

This is a case of being taken by the dealer, running slightly above normal temp is not going to be the hoses or tank unless they are obviously leaking. You should check for an air blockage now that they have opened the system, just be sure it was bled properly. An air bubble can inhibit coolant contact with the hot surfaces in the engine, causing steam to form.Other causes for running hotter than normal would start with radiator fans not running when needed. The causes can be in the activation system or the fan motor itself. Just let it get hot with the AC on and look to see that all fans are running. If one is not, this may be the problem. If this is okay, the thermostat is a likely candidate, sticking partially closed with a hot engine. A partially blocked radiator is the last candidate, harder to diagnose but still cpaable of causing overheating.

 

My fans did this to me last summer, but then magically started working. This summer, however they only came on once when I turned the climate control system from cool to full heat. The intel I have gathered so far says to check the fan control unit ($350),
check the coolant temp sensor by unplugging it and shorting pins 1-2, then pins 3-4 to see if the fans come on, and check the A/C control unit for diagnostic trouble codes, such as a faulty A/C pressure switch. My compressor cycles on and off when the car is idling in traffic and only blows cool air when I am moving at 35+ MPH, which s pushing air across the condenser. It has gotten a bit warm as well because the fans are not actuating.

 

My 2001 A6 Avant did pretty much the same thing when it's over 95 degrees or so. Once traffic freed up and I started moving again the temperature dropped back to normal. I'm thinking it's a design issue rather than a parts failure. I also switch to the Recirc mode which helps. That seems to stop the on-off cycling. The DC area in the summertime is not fun. I live in Fairfax VA which for those not familiar with the area is just east of DC.

 

how many fans should run when the car first shuts off? because my temp gauge will move up close to the first notch past normal after I shut the car off then turn it back on a minute after turning it off but seems to stay normal when driving even at low speeds and stopped at lights. I do live in Norfolk ,Va and it is around 97 degrees today.

 

This is normal as when you turn off your car air isn't circulating nearly as much as it would if the car was running and all fans were working.

On extreme hot days you will notice one fan will remain on after you shut the car off for several minutes to help the car cool off somewhat.

Once you turn the car back on from being off for a minute or two the coolant will be very hot as it hasn't been circulating through the system very fast.

 

Ok thanks for the help. I appreciate it a lot.