My lovely A6 is showing the Temp warning sign on the dash ! Its a 1997 model and i have recently replaced thewater pumpunit when it started over heating. Then a few days later warning light came on again but the temp gauge was not going over90 so i replaced theengine heat sensor ! no faults are showing up on the digisnostics computer ??? Im lost now when engine is hot i can open the coolant tank and not muc presure is released which might telll me that the headis not gone no smpke from exhaust etc

Any ideas will be greatfully welcomed i can only think of electrics as a problem or the fact that the water pump went might tell me water was used instead of coolant which might hav caused some hot spots around some parts of engine

Many thanks

 

howdy, many new cars are a PITA to get the cooling system purged of all the air in it. This could cause an air pocket at the sensor and no where else and that would lead to a high temp reading from that sensor. I am not familiar with your car but on many cars there are little air blead screws at high points on the system that you crack open while running and it spews air and coolant out to make sure no air is there. You could look around under the hood and check all coolant lines and fittings for these bleed screws. Air can be a nightmare. That is just a guess as to what you may be witnessing. hope it helps.