M42 cooling help

[Austin30]

My radiator is ice cold when motor is hot. Waterpump works fine and i cant seem to purg all the air out of the lines. Need help. Maybe someone has had this same problem before with there m42 motor its like the resovor will be steeming hot and the radiator will be ice cold like theres no flow but i u take the radiator off and run water through it it has about 80% flow.

[Vivek]

i cant seem to purg all the air out of the lines.

Sounds like you just need to bleed it but...

the resovor will be steeming hot and the radiator will be ice cold like theres no flow but i u take the radiator off and run water through it it has about 80% flow.

..this makes it seem like a clogged radiator.

[Austin30]

It seems like it would be clogged but when u take a water hose to it it had about 80%you flow out the bottom

[Dj Buttchug]

water is not pumping. theres an air bubble where the water pump is. you gotta bleed da shi yo

[series88]

Try jacking the front up or putting them on ramps. Run with heater on and reservoir cap off. that way the highest part of the car would be the front end. Air pockets will try to find its way to the top and hopefully out.

[oldmann]

May need bled, but sounds like thermostat is stuck closed.
Water pump is working? Did you just install a new one? If you did, did you put the thermostat in correctly, (air bleed hole up, facing correct direction).
Just because the water pump shaft is turning and not leaking does'nt mean the pump is working.

[bmwman91]

Did you recently do some maintenance on the cooling system? VERY often people have a clogged bypass groove in their thermostat housing, which really makes it a pain to get the air out. There isn't a bypass hole in the thermostat, or at least not in the 88°C ones that I have ever used.

[Balleristic31]

Water pump is working? Did you just install a new one? If you did, did you put the thermostat in correctly, (air bleed hole up, facing correct direction).
Just because the water pump shaft is turning and not leaking does'nt mean the pump is working.

This

[oldmann]

Did you recently do some maintenance on the cooling system? VERY often people have a clogged bypass groove in their thermostat housing, which really makes it a pain to get the air out. There isn't a bypass hole in the thermostat, or at least not in the 88°C ones that I have ever used.

If they don't, I drill an 1/8" hole in the frame at the top of thermostat.

I've never had an issue with bleeding, as long as I do this.

And your right about the groove in the housing, almost every time I've had one apart the groove is clogged up, except for the ones who always use distilled water with there coolant.

[bmwman91]

Yeah the bypass groove was a nice idea, but turned out poorly in reality. A simple hole in the thermostat body is more than adequate. Even with a totally clean cooling system, the rubber O-ring and paper gasket can easily block the groove. And if you use any sort of gasket sealer..forget it!

[kwill22]

Never understood why people had such hard times bleeding the M42. Never had to drill a hole in the thermostat either. Did you ever see the fluid pumping into the resevoir from the top hose?

[Austin30]

I see water pumping into the resevoir it just seems silly that the radiator would be cold if hot water was going into the resevoir

[Dj Buttchug]

This

dood ;D;D;D;D

[Austin30]

Im seemin to think that air is sucking from somwere under the intake. Because it consantly has air bubbling out the radiator cap amd i hear a gergling sound from somewere up under tge intake

[bmwman91]

I hate to even suggest it, but seeing air bubble out of the intake while running could be indicative of a cracked head or blown head gasket. Does the coolant level drop as the car runs and not go back up?