coolant level sensor 855 with b5252s 10v

[duke1]

hi all well yesterday and this morning was spent replacing the radiator on my 855 volvo the previous one was made in india by bangco and started leaking from the bottom seam after a about 18 months it had a 5 year warranty and the supplier had no bangco one to replace it with so sent me a valeo one all aliuminium that costs about 4retail £211! so its all fitted and tested and working sound now,however the coolant level indicator has never worked,i guess it needs a sensor? but the local volvo dealers no longer list it for my model of 850 but i found this online and hope it is right,it looks the same but is there any way of testing the original? this i think is same, https://www.ebay.co.uk/itm/363494046766 any ideas welcome,cheers all

[Luxobarge]

In what way has the coolant level indicator never worked, I mean is the light on all the time? If so, the usual culprit for this is that the float sinks, so the sensor thinks that the level is low. Fairly easy to check visually, even if you need to take the coolant header tank out for a good look. Fairly common fault, cure is to replace the header tank.

[4x4]

Carefully pull the sensor out the bottom of the expansion bottle and using an Ohms meter and a magnet you can check to see if the sensor is working. I checked mine a couple of months ago and it works fine.

NOTE... the bottle is almost completely empty before the light comes on

[duke1]

Originally Posted by 4x4

Carefully pull the sensor out the bottom of the expansion bottle and using an Ohms meter and a magnet you can check to see if the sensor is working. I checked mine a couple of months ago and it works fine.

NOTE... the bottle is almost completely empty before the light comes on

hi did try test it but my meter is shonky and not reliable so i did find a new one which i fitted today but having just 2 days ago fitted new rad and antifreeze i was loath to empty the bottle just to see if it works now but might as well finish the cooling system refit as i have done the rad,twice,heater matrix,waterpump,bulkhead coupling delete,all the water hoses and serpentine belt,question if anyone knows where the fan control sensor is located as its not on the rad itself,it is working where ever it is so thats good but i like to have a spare in the car just incase,my previous car a horrid peugeot 406 ate them at the rate 3-4 a year along with stepper motor!
much prefer the volvo to work on very sensible design mostly,i guess i have to see if the sensor works till next antifreeze change!peace

[Luxobarge]

There's no fan control sensor, the main engine ECU controls the fan operation, depending on a) coolant temperature and b) whether the aircon is on or not. Coolant temperature sender is also used for the temperature gauge on the dash, so if that's reading correctly (mid-way, 3 o'clock) then chances are the sensor is working fine - they're pretty reliable.

[duke1]

Originally Posted by Luxobarge

There's no fan control sensor, the main engine ECU controls the fan operation, depending on a) coolant temperature and b) whether the aircon is on or not. Coolant temperature sender is also used for the temperature gauge on the dash, so if that's reading correctly (mid-way, 3 o'clock) then chances are the sensor is working fine - they're pretty reliable.

hi it was the coolant level sensor i have changed but im used to cars with a fan switch on the radiator,yes the temp gauge works fine,i seem to have a good one electrical stuff all works even the odometer works!and i like this car and do plan on keeping it forever so try to ensure i have warning if coolant gets low as that is what killed my last car,mind you i was sort of glad when it finally died after 10 yrs,horrid thing just wouldnt die!never buy another peugeot !
aircon doesnt work and maybe next project,cheers

[4x4]

Originally Posted by duke1

...i was loath to empty the bottle just to see if it works ...

Use a turkey baster/syringe or similar to empty the expansion bottle.

I used a coolant hydrometer to empty my expansion bottle and decant it into a jug to allow me to test how much was left before the light came on