Changed cts coolant is now fine temp gauge problem

[Bclowes86]

I had an air lock and my temp gauge kept moving up and down. So had a full service empty and Re done coolant changed cts. But now the temp gauge takes ages to move and only moves when I been driving for 10 mins but when it does it constantly fluctuates Any ideas. Is it worth changing thermostat

 

[Chris4877]

Try cleaning the two metal prongs that are inside the coolant bottle, just rub them with a screwdriver, I had this same issue when I changed my CTS. The crap that builds up on the prongs messes with the reading

 

[gdjohny]

Sorry to hijack the thread but my wifes leon tdi has simillar problem : the temp gauge dosent move at all but sometimes when iam driving for longer and stop and start the car after few minutes the temp goes to 90 and then drops again.i have change the thernostat few days ago buy still no joy

 

[Bclowes86]

Gd johnny urs is the temperature sender by the sound of it mate

 

[Bclowes86]

Will do Chris just scratch them with a screwdriver yeah

 

[Chris4877]

Yup

 

[LEE69]

I had an air lock and my temp gauge kept moving up and down. So had a full service empty and Re done coolant changed cts. But now the temp gauge takes ages to move and only moves when I been driving for 10 mins but when it does it constantly fluctuates Any ideas. Is it worth changing thermostat

Only two things govern the dash gauge the CTS sensor and the thermostat.
The prongs in the coolant bottle are a level indicator only.

 

[Chris4877]

Strange, worked for me, I changed my CTS, it was still doing it and someone on here told me to do that and it's never done it since

 

[Chris4877]

But with that I know Lee knows a hell of a lot more than me so I would listen to him

 

[Seal_LCR]

As lee said the prongs stop the beep and three red flashes from the temp gauge.

If your having problems just change both if you are doing it yourself it's less that £20 with some coolant

 

[Bclowes86]

I have already done the temp sensor I know where the stat is how easy it is to change.

 

[LEE69]

http://forums.audiworld.com/showthread.php?p=16925102

 

[Bclowes86]

Lee one last think how quickly should ur return pipe be putting water back into ur expansion tank like what sort of flow should it be

 

[LEE69]

Should be a steady flow and faster when the revs are raised

 

[Bclowes86]

Okay thanks and also when I emptied and filled up the system I let it get to temperature the heaters where nice and hot so I put the cap on and went for a spin ten parked up left it till the morning then web I looked at the expansion tank in the morning the water level was over the top of the sensor so I opened the cap and it just made a glug glug and a bit of a hiss noise and then the water level dropped to minimum so I topped it back up. That was yesterday then This morning I opened the cap again to make sure it didn't make a hissing noise and it did a little bit and dropped a little more water so I topped it up. Is that right

 

[LEE69]

Yeah it's just settling down keep an eye on it.

 

[Bclowes86]

Okay I'm going to change my stat again today so I'll just do the same when it comes to the coolant I take it it just starts filling up bubbles in sytem when u have to top it up. Stat should be easier on the tdi think it's only two bolts

 

[LEE69]

Yeah stat is easy if you have the smaller sized socket set.
Top up with g12 slowly and re-bleed.

 

[Bclowes86]

Thanks for ur help lee I'll try it in a bit

 

[Bclowes86]

Also mate I had little bubbles coming in from te return last time I pressume this is normal too