Is this sensor needed?
Moderator: RichardW
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yellowperyl
Is this sensor needed?
After having some cutting out troubles with my Saxo Furio 1.4i I found that by removing the wire from the green temp sensor on the thermostat housing the car runs fine, I have been using my car with this sensor disconected for a number of weeks now without incident, why is this sensor fitted as my car appears to run fine without it?
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PowerLee
- Posts: 1260
- Joined: 01 May 2004, 19:49
- Location: United Kingdom
- My Cars: Current - Slightly modified 2016 Pug 308 Puretech 130 Allure
Past:
2003 - 206 GLX TU3JP & 206 SE ET3JP4
1995 - 405 Executive XU10J2
1996 - 406 GLX XU10J4R
1994 - 405 GTX XU10J2 - x 1
Yes that sensor is needed, It tells the engine ECU the coolant temp so it can adjust the fuel mixture.
Because its now unplugged the ECU will be stuffing either to much or to little fuel into the engine that will wreck the spark plugs & could damage your cat or in the worse case you could do some expensive damage inside.
You might also find when winter comes around that the car will be very hard to start.
A new sensor is around £13 from Citroen & you need a deep 19mm socket to fit it.
Make sure the engine is stone cold too when you change it, Hot coolant escaping under preassure when you unscrew the old sensor can & WILL burn you if your in the line of fire.
Because its now unplugged the ECU will be stuffing either to much or to little fuel into the engine that will wreck the spark plugs & could damage your cat or in the worse case you could do some expensive damage inside.
You might also find when winter comes around that the car will be very hard to start.
A new sensor is around £13 from Citroen & you need a deep 19mm socket to fit it.
Make sure the engine is stone cold too when you change it, Hot coolant escaping under preassure when you unscrew the old sensor can & WILL burn you if your in the line of fire.
just changed this on my xantia (CTS), cost £10.56 from unipart/partco automotive. this was the green one.
agree about NOT changing when hot, i changed when hot and coolant spilled out, luckily i was outside the line of fire
agree about NOT changing when hot, i changed when hot and coolant spilled out, luckily i was outside the line of fire
currently no citroens 
1.4 2000 forte now gone too
xantia 1.8i 16v dimension 1996P now gone,
1.4 2000 forte now gone too
xantia 1.8i 16v dimension 1996P now gone,
peryl -
while engine idle then try shortcircuit the cable removed from the green sensor. This simulates a hot sensor - and thus a hot (normal) engine temp. Your engine should now run a bit more stable and perhaps a bit lower idle rpm.
It may not do so - as the other sensors (Like the Lambda sonde - and air temp sensor) may be able to compensate the ECU signals.
The green sensor is a simple NTC resistor - high ohmic (some 5K ohms) when cold - low ohmic (some 500 ohms) when hot.
When it works that is
while engine idle then try shortcircuit the cable removed from the green sensor. This simulates a hot sensor - and thus a hot (normal) engine temp. Your engine should now run a bit more stable and perhaps a bit lower idle rpm.
It may not do so - as the other sensors (Like the Lambda sonde - and air temp sensor) may be able to compensate the ECU signals.
The green sensor is a simple NTC resistor - high ohmic (some 5K ohms) when cold - low ohmic (some 500 ohms) when hot.
When it works that is
Anders (DK) - '90 BX16Image