Audi a4 2006 overheats since the changing of valves

you have a cylinder gasket leak I think... is it blowing bubbles into the tank? if so then the head gasket is toast or the head is cracked either way.. not fun

What 'valves' did you change? Cylinder head? Then you have a bad head gasket. Any white smoke from exhaust?

NEED TO CHECK DAS FOR BAD SOLDERS AND THE TRNSISTOR AS WELL .CHECK ALSO TEMP SENSOR AT ENGINE.

-Flash the whole system with garden water from both direction.
-Check radiator's fin. If it clog , blow it out with air nozzle or best use pressure washer. But careful not to damage the fin. (Do not aim or point at angle and too close)
You should be good to go.

Mai

Start the engine with the valve body intact and fixed ... during idling pull out the valve body socket .... if the sound of engine change .. that's meant your valve body is good and if the sound is still the same than u need to change the valve body or you can sent it to your mechanic to do servicing and my recommendation is to change it.

your mechanic does not know what he is doing. you need to find someone with training and experience to fix it correctly.

SOUND LIKE TRANSMISSION SLIPPING. CHECK TRANSMISSION FLUID LEVEL.IF FLUID LEVEL OKAY BUT FLUID LOOKS DARK SMELL BURNT.CHANGE TRANSMISSION FLUID AND FILTER ADD SOME VALVE BODY TREATMENT TO LOOSEN STICKEN SHIFT VALVES.ADD TO TRANSMISSION FLUID DONT OVER FILL TRANSMISSION WILL CAUSE OVERHEAT. IF TRANSMISSION FLUID GOOD FILTER ALREADY BEEN CHANGED.IF ALL GOOD ENGINE BEEN TUNED UP OTHER POSSIBLE CAUSES FOR TRANSMISSION SLIPPING NOT GOING TO OVER DRIVE COULD BE THROTTLE SHIFT CABLE OUT ADJUSTMENT OR STRETCHED. TORQUE CONVERTER FAULTY OR SHIFT VALVES TO TORQUE CONVERTER OR OVER DRIVE STUCK IN VALVE BODY. VALVE BODY FAULTY. AND HAVE VECHICLE SCANNED FOR FAULTY VECHICLE SPEED SENSOR OR FAULTY THROTTLE CONTROL MODULE OR FAULTY THROTTLE POSITION SENSOR. THEY WILL EFFECT TRANSMISSION SHIFT TO OVER DRIVE IF FAULTY.

change thermost and/or water pump

mcdevito75 here, Your speaking about the Heater control valve, this allows hot water (antifreeze) into the heater core so as too give you heat, (hot air thru the dash vents). This valve could be sticking, you can try to tap on it with a wrench see if it helps. Before you just change it check all associasted vacumn lines to and from this valve, also check all vacumn lines to the firewall and at the intake manifold for bends, breaks etc.

Could be: fuel warm-up valve,
idle-speed stabilisation valve