V6 Coolant Temperature Sensor Replacement Writeup

Background and instructions:


  • screw driver ( Philips)
  • some string
  • one of those mirror's on a stick ( not necessary but made life a lot easier)
  • small hands ( optional but will reduce swearing and speed things up)


  • Coolant sensor ( green) some 99 b5s have a blue square sensor
  • Coolant sensor gasket
  • Retaining clip ( recommend you buy 2 just in case)

1. removes the flex hose from the air intake

  • There will still be a black section in the way (and I can’t figure out how to move it so you’re going to have to work at an angle)

2. look in there and find out witch one is the coolant sensor (it will have a black wire harness coming out of it ( and the sensor its self is black)

3. LEAVE THE WIRE HARNESS ON and reach down and pull the clip out to the passenger’s side (well call that left)

4 pull the sensor out carefully (you can use the harness just don’t pull to hard) it should come out

5 when it does come out make sure it has the gasket on it ( or at very least make sure it doesn’t have it and its still in there just know where it is) ( I thought mine fell into the car but it never came out the first time so ii spent like a extra half hour trying to figure out why it wouldn’t sit right with the new gasket and sensor )

  • Note: like a cup of coolant is going to gurgle out just let it go there is nothing you can do to stop it I tired and failed horribly
  • if the gasket doesn’t come out take a wire hanger and cut the long bottom part out make your self a little handle so you don’t drop it. Then the other end make a little 45 degree hook ( so it looks kind of like a fish hook barb) My gasket was so old and hard it felt like metal so I couldn’t figure out where it was by hand. Stick in the wire hanger and move it up and down till you feel the lip and then pull the SOB out

6. put the gasket on the sensor and then put that on the harness

7. shove the whole assembly into the whole move it around a little and make sure its not sticking up

8. take the NEW clip you have and tie the kite string around the clip ( preferably in a granny knot) ( if you don’t know what that is just tie a shoelace knot on it) the point is so if you pull up hard it will come lose but if you drop it you can fish it out ( since the clip weight virtually nothing) TIE THE OTHER END TO SOMETHING (I tied it around my neck because I was using both hands)

9. take the mirror and put it on the other side ( drivers side )_of the sensor so you can look down and see also try to get the flash light positioned so it rests with the light on the hole

10. put the clip threw ( the clip is very very similar to the fuel psi regulator set up were the clip goes threw to holes on the side over the sensor and out two more holes )

However the clip is behind the engine in a dark hole made of cheap plastic so in that respect no its not the same

Old black Temp sensor
New Green Temp Sensor

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