# a6 4.2 overheating issues



## biggiesmalls (Jul 4, 2008)

gentlemen, got an a6 4.2, trully an beautiful car. got some overheating issues. replaced tstat, water pump, high pressure switch, rad been flushed, all sensors been replaced, i think at least, but it still runs over the middle. 
anybody out there got any possible fixes to this problem?
thanks.


----------



## biggiesmalls (Jul 4, 2008)

*Re: a6 4.2 overheating issues (biggiesmalls)*

guys biggiesmalls here again...the car is a 2000 not 2006, otherwise it would be a warranty issue...so no headache then...
any help would be appreciated...i love the car but i am dumping too much cash into it...
thanks.


----------



## knowboost (Jul 7, 2008)

*Re: a6 4.2 overheating issues (biggiesmalls)*

Don't know if you fixed it yet but sounds like your radiator fan is not coming on...try the fan clutch here:
http://www.ecstuning.com/stage...oling
Or you can go with an electric fan kit (which I have) but it is a bit noisy...I would go OEM.


----------



## german performance (Sep 5, 2004)

*Re: a6 4.2 overheating issues (biggiesmalls)*

did you bleed the air from the cooling system during fill up? are you using G12, and no other coolant mixes? will the car overheat idling, or when driving? is there contamination in the radiator? did you install the t-stat the correct way? is it a factory water pump w/ plastic impellar, or a metal unit? did the old water pump disintergrate, and clog the cooling system? have you checked the temp with a vas5052, or vcds? is there a chance you have a defective gauge, or tems sensor? can you obtain a infa-red thermometer to check temps thru the radiator?
sorry, just the basic questions. sorry, but was it overheating _before_ you did the pump/stat, or after.


----------



## biggiesmalls (Jul 4, 2008)

*Re: a6 4.2 overheating issues (german performance)*

hey thanks for taking the time to answer this.
1. yes air was bled from cooling system
2. yes using g12 only
3. car overheats when idling normally but also overheats when driving hard
4. new radiator
5. t stat was installed correctly by Audi
6. dont know about the water pump, but it is factory
7. dont know if wp disintegrated but rad was replaced and when that was done i was told that rad was pretty much falling apart
8. I HAVE NOT CHECKED TEMP WITH VAS5052 OR VCDS. How do i do that or should i have Audi have a look at it?
9. no defective gauge, dont know about temp sensor
10. infra red readout done, and before t stat the readings were way off on top and bottom of radiator
11. car was overheating before and after t stat, water pump, etc.
12. viscous fan clutch has been replaced.
Question:
Other than t stat, what and how many other sensors control the cooling system please. I think there are three but nobody can answer that question for me definitively, not even my freaking Audi dealership!
Also, does the [auxillary fan?] secondary fan on a 2000 A6 4.2, have double speeds or is it just single speed?
And could a weak battery contribute to a cooling system problem, possibly not kicking in the secondary fan at the proper speed?
I am at my wits end. I have babied this car and I just want to enjoy this beautiful vehicle without having to worry about it freaking overheating all the time.








I will pay you for a long and drawn out explaination to the above queries and or any other comments that you think might be assist me.








Many thanks. 


_Modified by biggiesmalls at 10:27 PM 8-17-2008_


----------



## biggiesmalls (Jul 4, 2008)

*Re: a6 4.2 overheating issues (knowboost)*

hey thanks for that...yeah fan clutch has been replaced.


----------



## Slimjimmn (Apr 8, 2006)

*Re: a6 4.2 overheating issues (biggiesmalls)*

you need to vag com the ecm mvb 01. I will tell you correct engine temperature related to the coolant temp sensor (yes a very common issue with vw's its a 20.00 sensor that sometimes gives false engine temps to the instrument cluster. It has 4 pins, 2 for the ecm and 2 for the cluster)


----------

