Hi guys, I've been having issues with the temp gauge on the dashboard jumping to 980 and then back to 0 a few times during each drive of the car, plus for the first couple of minutes after starting the car it will jerk badly as if there's a problem with acceleration. My local mechanic says it is because of a faulty water temp sensor, so after a few hours of watching Youtube videos and checking parts sites I decided to try and replace it myself. The problem I'm having is this.....The part that all of the sites were telling me to buy, that would fit my car perfectly, seems to be the wrong part!! I've attached pics of the sensor I bought and tried to use, but it's too big for the actual pipe plus the electrical connector is wrong too. I don't know what I'm doing wrong!!!

Hello David, 

Your mechanic could be right, but it is not unusual to have two coolant temperature sensors/ senders ‘sensing’  the actual coolant temperature. If there are two, one will be sending a signal to the temperature gauge, and I would normally refer to that as a temperature sender. The second, will again sense the coolant temperature and send that ‘resistance value’ to the ECU to control the fuel mixture. I usually refer to this as the coolant sensor. Others may have different interpretations. 

Having said all that, it is possible (probable even) that yours ( fairly old model) just has one, and this would make more sense since you have two sets of symptoms. 

What you are suffering from here David is a confusion by on-line motor factors, and this is not at all unusual, so if this were mine, I would be wandering into my local Audi dealer and getting the recommended part from them. Yes, it will cost you more, but you cannot put a price on the inconvenience of being sent wrong parts. The dealers schematic will probably also show its location, so that’s a bonus. 

Kind regards,

Gareth.