bleeding the cooling system

[flanders118]

hello I have just changed the rad /thermo/ pump and im having trouble getting hot air
ran it for some time but no joy ended up snapping the bleed screw what's the best way

 

[Zeti]

Fill up the system, start the engine to normal temp. After the thermostat is open, open the heating to the max. With the bleeding screw open give it few Rev reprises. At the end refill to the sign.
Dan

 

[jonco]

When you are filling you should have the heater settings to full heat and blower fan on low before you start engine. on the M44 it helps if front end is jacked up to create high point at bleed.
Squeeze the various hoses with engine running and you should notice air being displaced into expansion tank. Once engine up to temp run heater on full speed - it will probably run cool to start and then heat should blast through.
Mine always takes a few days to fully settle down so check coolant level regularly until it stabilises.

 

[flanders118]

Just going to give it another try cheers

 

[flanders118]

Is the fan on all the time on the z

 

[jonco]

Is the fan on all the time on the z

If you mean the belt driven viscous fan then yes but the speed will vary with expansion/contraction of the thermal `block' in the fan hub.

 

[flanders118]

If you mean the belt driven viscous fan then yes but the speed will vary with expansion/contraction of the thermal `block' in the fan hub.

The fan on the radiator

 

[jonco]

The fan on the radiator

The original cooling fan design was belt driven viscous but some cars have been modified to have electric fan drive. A viscous fan looks like this

 

[flanders118]

The original cooling fan design was belt driven viscous but some cars have been modified to have electric fan drive. A viscous fan looks like thisView attachment 37667

No mine is on the rad but on all the time

 

[the Nefyn cat]

Shouldn't be running all the time, the engine won't be happy at all if it can't get up to temperature. Sounds like the thermo sensor has packed in, not sure where it would be on one like yours.

 

[flanders118]

Shouldn't be running all the time, the engine won't be happy at all if it can't get up to temperature. Sounds like the thermo sensor has packed in, not sure where it would be on one like yours.

Ok will have to try and find it

 

[DirtyDog]

I had huge problems when I changed my rad ( non bmw OEM but a Hella rad all the same which many parts are on a Zed )and refilled with coolant, all sorts of weird things happened, fan not coming on at all, fan on too much, coolant blowing out the expansion tank. you name it it happened.
I found it was mainly down to air in the system and needing a new filler cap ( sopers bmw for that, dont use aftermarket tried that and caused a lot of my issues) these on the M43TU at least have the pressure relieve built into them along with a seal
I found the Zed to be a real bi*** to bleed, took me ages and at least 4 drain/fills after watching youtube clips and different ways to fill/bleed.

Hope you get it sorted mate...

 

[Russell O]

Just put a new rad on mine and the mechanic over the way put a valve on the tank and sucked all the air out then opened another valve and it filled it to about 1" below the fill mark.. Topped it up and perfect ever since...

 

[flanders118]

I had huge problems when I changed my rad ( non bmw OEM but a Hella rad all the same which many parts are on a Zed )and refilled with coolant, all sorts of weird things happened, fan not coming on at all, fan on too much, coolant blowing out the expansion tank. you name it it happened.
I found it was mainly down to air in the system and needing a new filler cap ( sopers bmw for that, dont use aftermarket tried that and caused a lot of my issues) these on the M43TU at least have the pressure relieve built into them along with a seal
I found the Zed to be a real bi*** to bleed, took me ages and at least 4 drain/fills after watching youtube clips and different ways to fill/bleed.

Hope you get it sorted mate...

I think it's sorted