528 engine (m52tu) cooling questions/problems

[David87M3]

Hi,
I have an 2000 built 528 auto. The bottom radiator hose gets fairly hot, even in this cold weather. Radiator fins are cold (except were the top hose is).
Any idea's?
I am guessing the radiator is blocked/restricted somehow or the thermostat is not fully opening and any heat in the engine is being passed down the water thats sitting in the lower hose making it feel hot.

I put the instrument cluster into test mode (test7) and the coolant temp gets upto 105 degree's! also confimed this with carsoft.
I only noticed this becasue I keep hearing the electric fan cutting in.

Any thoughts as to what else it could be?

the engine does not appear to use water.


Thanks

[phelix]

The thermostat's are known for failing so it could be jammed shut. You could also have a slipping water pump impeller.

[David87M3]

thanks

never thought of the water pump, just assumed it was working


Dave