Which Temp Sensor?

  1. Saxperience Post Whore Joined: Oct 2009 Basildon And Corringham, Essex Posts: 5179 MK1 Focus RS, Discovery TD5, Renault Trafic 2.0
    #1
    Hi Friends, Quick Question.

    I can't get on AutoData right now, I have 2 Temp sensors on my VTR, one in the Rad and one on the Thermostat housing.

    Which ones is for the ECU? I assume it's the one on the Thermostat?

    Because, my problem being, the engine is sticking at the revs again like before, So I plugged my Diagnostic scanner in, the water temp is showing -40F even after it at working temp. the gauge is working, Fans works Etc... But on the Diagnostics it shows at -40F all the time, so I assume the ECU temp sensor is playing up and sending a funny signal to the ECU and just going "Blaaahhhhh!!" and that results in my Engine sticking at the revs.


    So, anyone know? Lol. I've unplugged both, so see if it makes an indication as to what one is what, but nothing happens apart from the fan comes on lol.


    Thanks, Ben.
  2. Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.
    #2
    On the thermostat theres 2 sensors the green 1 is the coolant temp sensor & sends a signal to the ecu,the blue 1 is for the temp guage reading.19mm deep socket to rmove either 1.

    Steve.
    1 user thanked this post:
  3. Saxperience Post Whore Joined: Oct 2009 Basildon And Corringham, Essex Posts: 5179 MK1 Focus RS, Discovery TD5, Renault Trafic 2.0
    #3
    Quote:
    Originally Posted by stevo67 View Post
    On the thermostat theres 2 sensors the green 1 is the coolant temp sensor & sends a signal to the ecu,the blue 1 is for the temp guage reading.19mm deep socket to rmove either 1.

    Steve.
    Thanks, what's the one on the Rad then? lol My MK2 don't have the Rad one, my MK1 (The Problem Car) Has it lol.
  4. Saxperience Hardcore! Joined: Nov 2007 Guantanamo Bay Posts: 28700 oyster card
    #4
    Quote:
    Originally Posted by Bikekid450 View Post
    Thanks, what's the one on the Rad then? lol My MK2 don't have the Rad one, my MK1 (The Problem Car) Has it lol.
    Could be the sensor to trigger the fan. irc mk1 is controlled by that sensor just there where as on the mk2 the fan is controlled by the ECU?
  5. Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.
    #5
    Quote:
    Originally Posted by Bikekid450 View Post
    Thanks, what's the one on the Rad then? lol My MK2 don't have the Rad one, my MK1 (The Problem Car) Has it lol.
    I think thats when your engine gets too hot that switch on the fan kicks in & operates the fan.


    Steve.
  6. Saxperience Post Whore Joined: Oct 2009 Basildon And Corringham, Essex Posts: 5179 MK1 Focus RS, Discovery TD5, Renault Trafic 2.0
    #6
    Quote:
    Originally Posted by stevo67 View Post
    I think thats when your engine gets too hot that switch on the fan kicks in & operates the fan.


    Steve.
    Ohh. Thanks.

    I thought it was that at first because the Rad was leaking around that sensor lol.
  7. Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.
    #7
    Quote:
    Originally Posted by Bikekid450 View Post
    Ohh. Thanks.

    I thought it was that at first because the Rad was leaking around that sensor lol.
    I think there is a little sealing ring around the sensor which may becomes brittle after a while causing it to leak.


    Steve.
  8. Saxperience Post Whore Joined: Oct 2009 Basildon And Corringham, Essex Posts: 5179 MK1 Focus RS, Discovery TD5, Renault Trafic 2.0
    #8
    Quote:
    Originally Posted by stevo67 View Post
    I think there is a little sealing ring around the sensor which may becomes brittle after a while causing it to leak.


    Steve.
    Ye I fixed that, when I put the new Rad in, I'd forgotten to tighten it lolol.

    I'll change the ECU sensor and see how it goes, thanks.