Strange over heating problem 1.8 tsi

[Funbobby]

Couple of months ago I had to change the water pump as car died on me which was all sorted and no problems since but a couple of days ago on first drive of the day the temp readings go really high and fans kick in but if I pull over and turn it off and re start the reading go back to normal (90) and no fans. So my mechanic changed the coolant sensor but still doing it, any ideas to what it might be ??

 

[Legojon]

Is your coolant level ok (and no sign of oil in it)? Check the oil filler cap make sure there's no sign of coolant. Air trapped in the coolant maybe? Not sure on that particular system, but on some systems you can crank the heater up to max and squeeze the pipes to try and get air out.

 

[SRGTD]

Faulty thermostat perhaps?

 

[Funbobby]

Coolant seems fine , apparently there is another sensor that goes on the block not sure if that’s the thermostat so maybe that ? Cooling system just seems problematic on these

 

[Funbobby]

Strange symptoms this morning, car was fine on first drive then stopped at some lights and engine turned off for stop start then temp gauge shot up to max so turned it off and on and right as rain again !

 

[CupraGeezer]

I would suspect an electric issue (i.e. a broken wire or a short) rather than an actual cooling problem.

Is there any sign that the car is really overheating (steam, water ejection, etc)? If so, then I would withdraw the above statement.

Also, the Leon has a system where it doesn't display the real coolant temperature. So long as it considers the temperature to be "normal", then it displays a temperature of 90 deg. I've no idea where this calcualtion is done or what the limits of "normal" are but I guess the fault could be in this module.

 

[Funbobby]

It’s not overheating just thinks it is ! Strange only does in once in a day and switching on and off sorts it every time? Don’t know if it’s linked to the water pump change recently as that appeared to be a big job

 

[ajg74]

We had a similar issue on our old DS4 with the 200thp engine, it had to have multiple sensors replaced to fix it (luckily under warranty) I would say this sounds like a dodgy sensor issue, just finding out which one........

 

[Funbobby]

so my local mechanic has said everything seems ok but recomends taking it for a software update with seat but i feel like im being fobbed off to be honest and im wondering if this relates back to the water pump they changed a couple of months ago.

 

[Walone]

so my local mechanic has said everything seems ok but recomends taking it for a software update with seat but i feel like im being fobbed off to be honest and im wondering if this relates back to the water pump they changed a couple of months ago.

Not sure on your engine but today I was looking at a post on VCDS users forum where it talked about a special bleeding procedure being required due to having electric water pumps as well as mechanically driven pump.

 

[Funbobby]

well after 6 months or so with no problems the car has decided it thinks its overheating again. pump and sensors have been changed back in march but today i had to pull over as it had gone into the red. left in 15 minutes and it seemed fine again? starting to lose trust in the car, any thoughts what might be going on?