Coolant Sensor Question

mentaldave · Nov 8th, 2006, 12:06

Hi,

I have a 1992 1.8i volvo 440.

I have recently replaced the Oxygen Sensor in an effort to stop the car from running rich and surging. This did not work so I decided to replace the coolant sensor.

I got the correct part, matches up with the one in Haynes and removed the old sensor from the rear of the block.

This one was completely different. The probe for detecting the coolant temperature was half the length. So I thought maybe someone had fitted the wrong part so I put the new sensor in which fitted and did up ok. As soon as I started the car the temperature on the dash gague started to climb rapidly. It did so till it nearly hit the red at which point i took it off. I put the old sensor back in and the temp was fine. Tried the new sensor for the second time and this happened again. It seems as if the length of the new sensor is blocking off the water channel completely.

Is it possible that the engine has been swapped out at some point and an older renault engine been put in? Is there a way I can tell?

Any help will be much appreciated.

Thanks,

David

gnhuk · Nov 8th, 2006, 16:48

I replaced the ECU temp sender on my 1.8 S40, to cure (successfully) a similar problem, and this is located just beneath the thermostat. I believe there's another one for the temperature gauge on the dashboard but I'm not sure where it is. Have you used an ECU temp sender in place of the "other one"?

Just a suggestion..............

mentaldave · Nov 8th, 2006, 17:11

Ahhh that makes sense!

Does anyone know where the sensor is for the ECU? Mine appears to only be one wire! Haynes manual don't give much help, they just give me a picture of it lol

David

gnhuk · Nov 8th, 2006, 18:52

My ECU sensor is by the thermostat and has more than one wire - I don't know where the other one is - clues anyone

Nov 13th, 2006, 17:02

i had the same problem with my 440, was running rich all the time, this was due to the "coolant temp sensor" as it was the wrong 1 i had bought to cure the problem and the fueling was running at the factory settings as the ECU had no information from the sensor, cure = new sensor, wrong 1 again, as you described, the temp gauge climbed faster than b4 as the resistance for the sensor is different for each engine size, next sensor was right, fitted perfect, matched the 1st 1 and the car runs sweet as a nut now. ope this helps m8y

jlgrosvenor · Jul 29th, 2007, 21:53

Just been looking through the threads as I need to replace the water pump on my 440si (1995) after a massive 26,000 miles and 2 years

. When the weather is cold and car moving fast, the temp gauge shows below halfway. When stationary or in hot weather, the gauge is always above halfway. During the water pump change, I will change BOTH of the temp sensors and the thermostat (about £10 each and £8 for the thermostat).

There is a temp sensor on the back of the cylinder head (clutch side) which gives the signal to the instrument cluster. There is another one (blue head on my car) on the front of the head on the same side that gives the signal to the ECU and controls running/fueling.

HTH some people in future

Nov 8th, 2006, 12:06	#1
mentaldave New Member Last Online: Feb 5th, 2024 15:08 Join Date: Oct 2006 Location: Edinburgh	Coolant Sensor Question Hi, I have a 1992 1.8i volvo 440. I have recently replaced the Oxygen Sensor in an effort to stop the car from running rich and surging. This did not work so I decided to replace the coolant sensor. I got the correct part, matches up with the one in Haynes and removed the old sensor from the rear of the block. This one was completely different. The probe for detecting the coolant temperature was half the length. So I thought maybe someone had fitted the wrong part so I put the new sensor in which fitted and did up ok. As soon as I started the car the temperature on the dash gague started to climb rapidly. It did so till it nearly hit the red at which point i took it off. I put the old sensor back in and the temp was fine. Tried the new sensor for the second time and this happened again. It seems as if the length of the new sensor is blocking off the water channel completely. Is it possible that the engine has been swapped out at some point and an older renault engine been put in? Is there a way I can tell? Any help will be much appreciated. Thanks, David

Nov 8th, 2006, 16:48	#2
gnhuk Balding............. Last Online: Jun 29th, 2018 10:35 Join Date: Dec 2003 Location: Linslade	I replaced the ECU temp sender on my 1.8 S40, to cure (successfully) a similar problem, and this is located just beneath the thermostat. I believe there's another one for the temperature gauge on the dashboard but I'm not sure where it is. Have you used an ECU temp sender in place of the "other one"? Just a suggestion.............. __________________ Gavin VOC17969 2000 S40 1.8S -with various options (Now sold @135k miles) 2012 S40D3 R-Design Last edited by gnhuk; Nov 8th, 2006 at 18:52. Reason: spelling.........

Nov 8th, 2006, 18:52	#4
gnhuk Balding............. Last Online: Jun 29th, 2018 10:35 Join Date: Dec 2003 Location: Linslade	My ECU sensor is by the thermostat and has more than one wire - I don't know where the other one is - clues anyone __________________ Gavin VOC17969 2000 S40 1.8S -with various options (Now sold @135k miles) 2012 S40D3 R-Design

Nov 13th, 2006, 17:02	#5
jubjub Guest Location:	coolant temp sensor ? i had the same problem with my 440, was running rich all the time, this was due to the "coolant temp sensor" as it was the wrong 1 i had bought to cure the problem and the fueling was running at the factory settings as the ECU had no information from the sensor, cure = new sensor, wrong 1 again, as you described, the temp gauge climbed faster than b4 as the resistance for the sensor is different for each engine size, next sensor was right, fitted perfect, matched the 1st 1 and the car runs sweet as a nut now. ope this helps m8y

Nov 8th, 2006, 17:11	#3
mentaldave New Member Last Online: Feb 5th, 2024 15:08 Join Date: Oct 2006 Location: Edinburgh	Ahhh that makes sense! Does anyone know where the sensor is for the ECU? Mine appears to only be one wire! Haynes manual don't give much help, they just give me a picture of it lol David

Jul 29th, 2007, 21:53	#6
jlgrosvenor Member Last Online: Aug 25th, 2016 13:11 Join Date: Aug 2006 Location: Chesterfield	Just been looking through the threads as I need to replace the water pump on my 440si (1995) after a massive 26,000 miles and 2 years . When the weather is cold and car moving fast, the temp gauge shows below halfway. When stationary or in hot weather, the gauge is always above halfway. During the water pump change, I will change BOTH of the temp sensors and the thermostat (about £10 each and £8 for the thermostat). There is a temp sensor on the back of the cylinder head (clutch side) which gives the signal to the instrument cluster. There is another one (blue head on my car) on the front of the head on the same side that gives the signal to the ECU and controls running/fueling. HTH some people in future

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