This is how I changed the engine coolant temperature sensor with help from a mate. This job needs a second pair of hands as you can’t reach for the new sensor and the tools you need whilst removing the old sensor. If you choose to do this yourself you do so at your own risk. Make sure the engine is cold!

The old sensor has part #078919501C, whilst the new sensor has part# 059919501A you are also best to get a new o ring and a new clip just in case. If your coolant is on minimum, you might want some more of that too.

1. Remove engine covers

2. Remove under tray - both parts

3. Unclip large hose to allow room to work

4. Remove electrical connector from sensor using flathead screwdriver – best done from underneath

5. Remove sensor retaining clip - best done from underneath

6. Remove old sensor and quickly put your finger in the hole to stop coolant leaking – best done from above

7. Remove the finger bringing with it the old ‘o’ ring quickly place another finger in the hole to prevent further coolant leaking – best done from above

8. Remove finger and quickly place new sensor (fitted with new ‘o’ ring) into place – you will lose a bit more coolant – best done from above

9. Fit the new clip

10. Re fit the wiring to the new sensor

11. Refit large hose, engine covers and under tray – job done

Here is an image of the engine bay from the offside, the sensor is circled in red

Here is a close up photo of the sensor

The car now runs better, I am getting a higher mpg - maybe the engine was running rich with a dud sensor?

Much thanks to my mate for all his help

Any questions please ask away.

Cheers for the info man.

If you're feeling nimble you can even do this in situ without removing the hose or under trays, although it does mean you have to feel around a bit and it's fiddly. Plus, on your own you will lose some coolant, but it doesn't all flow out, about a pint or so perhaps. Just remember to top it off and swill any off that spilt onto the engine.

Edited 9 June, 200917 yr by allclownsareevi