Hi, help needed please. i need to change the engine sensor for the coolant temperature on my 1.9TDI Octavia. I looked at recent threads and it doesnt seem to be where they suggest. The only suspect i can see seems to be at the back of the engine fairly low down. can anyone confirm if i'm on the right track? if yes, how do i get the plastic clip(s) undone without breaking them/it?!

Also how easy is it to change the coolant expansion bottle? Can anyone give me an idiots guide? have to admit, i need it!

Thanks

Not sure about the sensor as I have an 1.8t

But the bottle is simple, just do it when the coolant is cool and you can't really go wrong. I think there is two maybe three pipes under there just take them off and replace them like for like. You will lose a dribble of coolant but if plug it quick with your finger then transfer it into the new bottle you should be fine and not need too top up.

It's a while since I did this so may have missed something out, but in all honesty I knew nothing about this job when I did it and just looked at what I had and went from there.

HTH

Thats good thanks. I need to change it as i'm fed up of false alarms on the low water sensor. i tried cleaning the metal sensors, but with limited success. it worked for a few days and now its back again.

cheers

just had mine off, there is 2 philips screws holding it in place and a small tube in the top and only one pipe in the bottom and you just squeeze the clips with a pair of pliers and of course the electrical connection, try giving it a good cleanout first as its only 2 wires to see if that solves it and top up with new anti freeze mixture ( red ) cheers - Stuart.

Edited 16 October, 200817 yr by sparky2

Thanks Stuart, i'll give it a go.

Hi, help needed please. i need to change the engine sensor for the coolant temperature on my 1.9TDI Octavia. I looked at recent threads and it doesnt seem to be where they suggest. The only suspect i can see seems to be at the back of the engine fairly low down. can anyone confirm if i'm on the right track? if yes, how do i get the plastic clip(s) undone without breaking them/it?!

Changing the temperature sender is quite easy. It is on the right hand side of the engine block in some of the pipework (may need to remove engine cover - I can't remember!).

1. Disconnect the wiring loom plug (this can be a right b!tch)

2. Put new o-ring onto new sender unit

3. Remove retaining clip

4. Remove old sender and ensure old o-ring comes out too

5. Insert new sender unit complete with o-ring

6. Insert retaining clip

7. Connect plug back onto new sender

I'll see if I can track down a picture of the sender a bit later.

I think I did this once by mistake and you start to drain the anti freeze out as soon as you pull it out of its rubber bung ! so have your new one ready to pop in as you pull this out unless you want to refill with anti freeze. cheers - Stuart.

For the temp sensor pulling out the clip which holds the sensor in is a pain, so is disconnecting the wiring plug, see if you can rotate it to make it easier to remove. The plug is one of those annoying ones you need to pull and push at the same time.

Get a torch and a mirror and have a good look first. I should have taken some pictures when I did mine. I found the O ring didn't come out with the sensor so you need to reach in the hole and pull it out. The coolant also pours out remarkably quickly to so you'll need to top it up afterwards and it will make a bit of a mess.

Good luck.

This thread should tell you all you need to know, as although most of the pics are for a different car, and engine, it shows the location on the 1.9 diesel, and shows how to get the clips off for the sensor. The easiest thing is to get the old sensor out and let it dangle, and jam the new one in as quick as you can. It should be a good enough fit to stop any leaks, and it'll mean you can sort out the wiring at your leisure! Although it's not good practice, I didn't change the O-ring on either of the ones I did, and a check on the one on my wife's car when I changed the 'stat body shows it's still in tip-top condition after what must be seven years...

Thanks to all, i've got no excuse not to get my **** in gear and do the job now!