(T) 1.6 Active sport Stilo - cooling/throttle fault

Hi all,

I bought a stilo few weeks ago now. car ran like a dream for first few days, then suddenly whenever I started the engine from hot/cold, when the management system did the start up check, the temperature gauge would go straight to maximum with warning light, then drop straight back to where it should have been and be fine. but the screen would tell me 'stop engine' ' cooling temperature high'.
After half hour of driving car, when the car was stationery at lights or a roundabout, as soon as i would take off the car would say 'stop engine' again, the yellow engine warning light comes on and the car will only do maximum of 20mph. I would then have to pull over, stop engine and restart then car would be fine again, but yellow light would stay on.

I took car to Fiat dealership, who didnt have a clue about customer service, and no idea about fiats either! after spending £100 on labour investigations, they thought it might be the throttle but could not give me answer without further investigations which I am very reluctant to as they have messed me round a lot.
After this the car was running perfectly some how, for 2 days, then suddenly the problem came back again this afternoon. the temperature gauge goes straight to max then drops to bottom again and is fine, and yellow engine warning light is back.

up to now, one part of the throttle has been changed and both temperature gauges on the engine.

Can anyone help me out please? i am running out of options.

haysca

with temp sensor replaced - it would (most likely) be a wiring fault also worth while cleaning your throttle and MAF sensor + the famous D4 connector (although i am not sure if temp sensor would go via D4.. it might be wired up directly to ECU)

Use these guides below:

https://www.fiatforum.com/stilo-guid...rol-valve.html

https://www.fiatforum.com/stilo-guid...-circuits.html

https://www.fiatforum.com/stilo-guid...ery-earth.html

https://www.fiatforum.com/stilo-guid...connector.html

Thanks for such a quick reply!!

Ha! A few jobs there then for the weekend!


I'd have a very close look here where K36 -the engine temp sensor- actually connects to the ecu. Look and check for a problem at the connector to the ecu itself

The fact the eng temp sensor gauge AND the warning comes up means the ecu is being told (incorrectly) of excess temp and note that that's a low or no resistance. So you're looking for a short circuit rather than an open circuit ie bad connection. So look for something that is bridging the connector pins perhaps or corrosion between the two or damage to the wiring from K36 to the ECU causing a short


Here's how the resistance v temp should look

Useful post from Decks (as per usual) but I'd also try a bit of lateral thinking and check all 4 coils are good. Will cost you the price of one coil but you should have a spare anyway.

Like your style Argo

There's also a possibility of a bad earth from the ECU as the throttle body and the engine temp are on similar reference voltage circuit