Bvarghese

My car tends to overheat while driving in heavy traffic conditions ... sometimes the temp goes up all the way to 120deg.

My normal temp is 90deg.

I just had the thermostat valuve changed recently.

What else could it be?

PaulW

If you have the AC on (HVAC unit in "AUTO"), then the low speed electric fan should be on all the time.

Once the temperature rises via the coolant temperature sensor, the fan should go to speed II, which sounds like a hoover craft....does it do that?

If not, you might want to check what the reading of the coolant is via vag-com. If it's bad, then you'll need a new coolant temperature sensor.

PaulW

One last thing, make sure your system is full and vented

Dale Vishnevski

Hi gentlemen,
Mine is Audi A8 D2 1997 3.7 FWD. I have been having the problem with the transmission and this problem is still ongoing. 1st gear is fine then it moves to 2nd also fine but in second it slips to 3rd and the power I lose instantly. If accelerating then it throws into limp mode. If it is not an uphill then 3rd slowly evens up then it is fine as you do not need to accelerate too much.
Why i am writing about it here is that in winter more or less the transmission behaved the way I described, but little more heat and 2nd slips faster and 3rd takes me to the limp mode. My temperature gauge does not go over 90 degrees. Usually in a cold weather it is little less then 90 but in hot weather it stays on 90 and auxiliary fan begins to work even without AC on. I have not charged the AC yet, though.
So, what I am driving at is that I do not know why such a little difference in change of temperature effects the work of the tranny? Of course, I will try to fix it, but what can be the real reason for even a slight overheating as I feel it especially if in a traffic.
I have checked the coolant temperature sensor one that is in the rear of the engine and another in the front on the head and they work Ok when removed and checked by the technician. Before it used to overheat as the thermostat was stuck and resistor plate for auxiliary fan did not work. I replaced them both. Thermostat is not even a year old. The resistor works on all speeds (checked separately), but little overheating, even if it is overheating when the gauge shows 90 sharp, has such a dramatic effect on the performance. Is it possible that the condition for the transmission can cause load on the engine?
I would appreciate your advice and suggestions.
By the way, I am in the country where there is only a handful of trustworthy mechanics and no dealers practically, so advise to go to the dealer would be a dead end for me.