m50 engine running cold

[japcarkiller]

ok it an m50 engine and its running cold. only gets out of the blue if i sit in traffic. I guess the thermostat is stuck open. ordering the new thermostat tomorrow. Checked my haynes and it doesn't cover the m50. So how do i go about changing it?
i bet one of ya knows. share the knowledge guy and gals.

[Jamesb318is]

i think they're the same as on later engines (m54 etc)
on the front of the engine there should a coolant pipe going to a plastic housing bolted the the front of the head with 10mm's. To get to this you will almost certainly have to remove the fan shroud ( a couple of clips/ screws) and the viscous fan. This has a 32mm opposite thread nut.
The 'stat is in this housing, just remove from head and replace (along with o-ring) (also check stat is the same temperature rating)

Sorry if this is wrong, i can only picture the m52/54 engines, but they are very similar in terms of basic layout

[japcarkiller]

thanks dude.
Any one know for certain. there must be some one that knows about the m50.
a few pics would be really cool.

[Brianmoooore]

Yep, jamesb318iSs description is close enough, although early engines havge a metal stat housing with a gasket rather than an O ring.

[japcarkiller]

found a cool guide for an e36 m50. the guide is for flushing the system and changing the thermostat.
So my new question is........... Do i have to drain the system b4 i can change the thermostat. or is it just a straight swap job?

[Brianmoooore]

You don't have to drain the system, but you'll lose a fair bit of coolant anyway, so it would be a good time to drain the coolant and replace it unless it's nearly new.