golf 1.9tdi bxe coolant issue

[dean.st]

I sorted the electrical issue but now i thought i had a temp gauge issue.

Turns out the lower half of the rad is not getting hot.

My first thoughts are stubborn airlock or stuck thremostat.

I replaced the thermostat but exactly the same.

Surely i can't have an air lock in exactly the same place? The rad was new but has run hot before this strip down.

So as not to cook the motor i'm going to remove the 'stat tomorrow.

Any ideas? are these notoriously stubborn to rid an airlock?

There is no blockage as i've filled the rad with hot water and it runs throughout

[Roverfan]

I sorted the electrical issue but now i thought i had a temp gauge issue.

Turns out the lower half of the rad is not getting hot.

My first thoughts are stubborn airlock or stuck thremostat.

I replaced the thermostat but exactly the same.

Surely i can't have an air lock in exactly the same place? The rad was new but has run hot before this strip down.

So as not to cook the motor i'm going to remove the 'stat tomorrow.

Any ideas? are these notoriously stubborn to rid an airlock?

There is no blockage as i've filled the rad with hot water and it runs throughout
These are meant to be vacuum filled and can often be problematic if coolant is not vacuum filled.

Do remind what the symptoms were and what engine and what you have already tried like squeezing the hoses etc. If I recall correctly you had low temps showing with no overheating on a bxe?

[dean.st]

It took me the best part of 2 hours this morning to get the coolant to fully circulate and remove the air bubbles. I was not buying a vac kit.

Now although the engine is hot throughout, the rad fan isn't kicking in and the coolant temp gauge takes forever to get just a 1/4 way up. It sits normally at 1/2 way (90). I also have the coolant symbol flashing on the info screen even though the water level is fine.

There is power to the fan at the plug.

[dean.st]

I've just run power straight to the fan and no action. However there is a green wire and a black wire (which i assume is the trigger wires from the sensors?) do i need to bridge either of these to the 12v live to get motion in the fan?

[Roverfan]

I've just run power straight to the fan and no action. However there is a green wire and a black wire (which i assume is the trigger wires from the sensors?) do i need to bridge either of these to the 12v live to get motion in the fan?

It'll be digital signal controlled by the ecu. Output test with vcds may be easier

[Crasher]

Yes the main fan is the controller and is commanded by a LIN BUS signal from the engine ECU

[Adam95]

My coolant is not properly circulating after a water pump/timing belt replacement. What did you do to get it to fully circulate and remove the air bubbles?

[Crasher]

Can you find out which make of pump was fitted?

[Adam95]

It was a eurocarparts pump, I’m not sure which one as my mechanic purchased it but I could find out.

[Crasher]

It could provide a clue, we only fit genuine pumps and cam belt kits for peace of mind, well in theory as mine started leaking after a year and there was no way I was following the TPS warranty procedure and taking it to Skoda for some spotty trainee oik to break.