Location of temp sensors/sender

[Gil3Jones]

I need advices as to where to find the temp sensors on a VY 6yl supercharged Calais. Problem is second fan won't start in hot conditions. Fuse and relay OK. Jumper the relay pins and fan starts so I just need to find the sensors.

 

[Immortality]

There is only one sensor for the PCM and it located underneath the thermostat housing at the back of the manifold on the passenger side. A bit of a PITA to get to.

The 2nd fan doesn't come on till 108°C if I remember correctly, are you sure you are getting that hot?

 

[Gil3Jones]

Thanks for the reply. It only rarely gets that hot - usually on a hot day stuck in traffic with the climate control running and the temp alarm sounds. The second fan is not operating. Once I move off it get back to normal. I really would like to fix this issue.

 

[krusing]

Make sure that you blead the Air out of t he L67 Cooling systems,
There is 3 Bleed points,

1. On the Radiator Return Pipe
2. Under the Snout
3. Under the Air intake Elbow, [under the Boost Valve]

Air lock in the L67 cooling system can do exactly what you described,
I put Anti Freeze/Anti-boil in and was able to see the colour of the water coming out when bleeding it, especially on the back one.
Don't unscrew them to far [say half a turn], because if they fall out,
you will be saying a few extremities, because you wont be able to find it.
To push most of the air out when its cold, open all 3, then place the hose in the radiator filler, with a little bit of water pressure by placing a rag around the hose on the neck of the radiator filler, and it will expel/push the air out the bleed holes, then tighten them, and get it up to temp, and open them again one by one.
Let it cool down and check the water again.
Hopefully that will fix the over-heating issue.
My temp gauge ALWAYs sits just under half way, on Hot and Cold Days, even with the Air on stinking hot days.

 

[Gil3Jones]

Thanks for your advice and I will certainly do wat you suggest.

A question though - why would air in the system prevent the second fan from starting in very hot conditions ?

Gil3Jones

 

[Gil3Jones]

Another question - I cannot see/find the coolant bleed valve (No.3) at the back of the motor 'under the air intake elbow'.
Is it visible or do you have to dismantle bits to find it ? I take it is on the passenger side at the back side of the motor manifold or is it right behind the end of the motor ?

Can you lead me to it please ?

Tks

 

[Immortality]

I drill a tiny hole in the thermostat to help bleed the air out from under the thermostat. The bleed screw is on top of the thermostat housing.

 

[krusing]

"Another question - I cannot see/find the coolant bleed valve (No.3) at the back of the motor 'under the air intake elbow'.
Is it visible or do you have to dismantle bits to find it ? I take it is on the passenger side at the back side of the motor manifold or is it right behind the end of the motor ?

Can you lead me to it please ?

Tks[/QUOTE]"

I have found a generic photo on the web, and have circled the bleed point locations with red circles.
Hope this helps.
The one at the back, is in front of the air intake elbow [at the bottom of it], but maybe hidden under the boost actuator vacuum pipe,
It looks the same as the other 2, on the Coolant Return Pipe, and Under the Snout.
If you still can not locate it, let me know,
If I get a chance, I take the cover off mine, and get a close up photo.

1/4/2019
I have included photo's of the actual Bleed points for reference.

1. On the Radiator Return Pipe
2. Under the Snout
3. Under the Air intake Elbow, on top of the thermostat housing [under the Boost Valve]