Seat Leon tdi temp gauge fault

[lewis.bates.73]

Before we start i know this is an audi forum but it has the same engine as my audi just need some advice please

Hi there I have just brought a seat Leon 1.9 tdi 110 and I've noticed it gets up to temperature then it drops down then back up ? I wanted to know if anyone could tell me what might be causing this ? And will this fault be stopping my fans from coming on or not ? Thanks
Lewis

 

[@udi A3]

First i would test the temp readings wth an external gauge or vcds. if the display reads wrong could be the temp sender or clocks. if clocks are suspect check the earths around the ecu and battery.

Do the other needles do the same?

 

[lewis.bates.73]

First i would test the temp readings wth an external gauge or vcds. if the display reads wrong could be the temp sender or clocks. if clocks are suspect check the earths around the ecu and battery.

Do the other needles do the same?

No it's just the temp one that's it been told could be coolant temp sensor if it is would it effect my fans coming on

 

[@udi A3]

possibly but doubtfull, the temp switch in the radiator should control the high and low fan speeds. iirc that CTS is just ecu and dash info.

 

[A4_MaJiK]

More than likely it will be the CTS. VAG use 4-pin sensors on most vehicles, 2 pins for the ECU and 2 pins for the temperature gauge. You may get reduced fuel economy if the ECU side is faulty.

 

[pablo]

if it drops on a fast light load run (eg cruising on motorway) then comes back up in traffic it will be the stat stuck open imo.

 

[jojo]

if it drops on a fast light load run (eg cruising on motorway) then comes back up in traffic it will be the stat stuck open imo.

I'd go with this.

 

[lewis.bates.73]

Thanks guys much appreciated i willl do some more digging