e30 M42 318is with a big air bubble in the coolant system?

[finite]

Hey all!  Great forum.. I've just got my hands on a e30 318is, i was told it had had a M44 put in it with the M42 inlet and electronics... however I'm now convinced its an M42 engine out of an e36 with the old M42 inlet and electronics from the e30 M42.  

Here's the problem (well one of many) - the temp guage doesn't rise (comes off rest with ignition but no further), and the heater doesn't blow hot air.  I've replaced the thermostat and bled as per instructions on this forum but to no avail.  The car is also extreemly hard to start when cold, after a few minutes it idles fine - been told that this could be the temp sensors?

So am I on the right lines when I think that it could be a big air lock in the coolant system which bleeding after the stat change hasn't cleared?  This is causing the temp sensors not to pick up a reading and the heater not to get hot?  

Or....?

** note to mods - just noticed i've probably put this in the wrong place  **

I'm really stumped!  Have spent 10 hours out in the snow today trying to get to the bottom of this.

[xwill112x]

posssibly.


maybe you have a shitty thermostat....




but to bleead the system, you need run the car a little (to atleast warm the oil up)
turn your heat on all the way, fans on 4


un-screw your bleed screw, rev it p to like 3k...hold it there till you blow only coolant out the bleeder...no air.

while still holding revs, close the bleeder screw.


thats how to bleed it, if that doesnt work...its either a shitty thermostat...or its just fubar....

[rambozo]

posssibly.


Maybe you have a shitty thermostat....




But to bleead the system, you need run the car a little (to atleast warm the oil up)
turn your heat on all the way, fans on 4


un-screw your bleed screw, rev it p to like 3k...hold it there till you blow only coolant out the bleeder...no air.

While still holding revs, close the bleeder screw.


Thats how to bleed it, if that doesnt work...its either a shitty thermostat...or its just fubar....

not at all...it's not the way to bleed that engine . Just put key on (engine not running totally cold) with heater knob to max hot , unscrew the plastic bleeding screw beside filler hole , fill coolant until coolant leaks bubble free out of bleeding screw , screw blleding screw and it's done . Level will go down to the max level on expansion tank on the radiator by itself after driving the car for 15 minutes

[xwill112x]

yea, since ya know...thats never worked for me or anything.
Now that i'm thinking, i've never even bled my coolant system, so how would i know what i'm talking about?

[bmwman91]

Towing to the right section........

[visionracingdevelopments]

Turned out it was a blocked heater matrix, failed water pump and failed thermostat.


I've got the same problem (yay).

[RED IS 91]

posssibly.


maybe you have a shitty thermostat....




but to bleead the system, you need run the car a little (to atleast warm the oil up)
turn your heat on all the way, fans on 4


un-screw your bleed screw, rev it p to like 3k...hold it there till you blow only coolant out the bleeder...no air.



while still holding revs, close the bleeder screw.


thats how to bleed it, if that doesnt work...its either a shitty thermostat...or its just fubar....

This is the way I've done it many times ,only thing is to warm the motor up until the thermostat should open before opening the bleed screw,don't let the motor over heat ........Only an idiot:eek: would do what rambozo says.