temp sensors

[jimbob88]

im having a few "problems" with my m50 manifold swap mainly becuase the engine is out of the car and both manifolds were off when i bought it but im getting there
one thing i have noticed is underneath the intake ports are the temp sensors and a coolant outlet for the thottle body, thing is i only have one temp sensor hole and the hole for the outlety IE 2 holes instead of 3, anyone know why?
heres a pic i nicked form the m50 sticky im missing the hole for the middle one, the 2 wired temp sensor.
it hasnt been filled in or anything it has the place where it should be it just hasnt been drilled out ??

[E30BeemerLad]

This has been covered before somewhere, but my understanding is that you will have to fit the temp sensor where the outlet is, but the thread isn't right so you need to get the thread turned down on the M20 temp sensor before it will fit in the location where the coolant outlet is.

I'm pretty sure that is the case but would wait for clarification from Yoda (Dan).

I think the later heads only had the one sensor hole, whereas my head (the one in the pic) is of 1995 vintage and has the extra hole

[DanThe]

Couple of pics ive just found on the net





You need to get rid of the stub (throttle heater) and turn the thread down to 12mm on the brown sender, cant remember the pitch size

[jimbob88]

Brilliant thanks lads

[Davyc2]

My head is the same, I put the brown sensor in the drill and rubbed a file on it to take off the old threads then I ran an M12 x 1.5 die up on it, fits perfect in the old throttle body pipe outlet now

[jimbob88]

haha blue peter stylee. love it thanks

[jimbob88]

Would it not be easier to drill the outlet hole and tap it to the size of the temp sensor? Then if the sensor needs changing its just a case of screwing the new one in

[Davyc2]

Would it not be easier to drill the outlet hole and tap it to the size of the temp sensor? Then if the sensor needs changing its just a case of screwing the new one in

Yes it would be easier , as long as you're confident that bits of metal don't fall into the engine during the process. I modified my temp sender while the engine was in the car and inlet manifold was still attached to the engine, so drilling and tapping wasn't really an option for me

[jimbob88]

Oh see. Mines on the engine stand with the mani off still so i think i'll drill it and tap it while i can

[e30-EVN]

do it now mate, sooo much easier than when the lump is in situe!

i changed my temp sensor the other day and although not a difficult job i couldnt get the feckin spanner in there to undo the t w a t! got there in the end though lol

[jimbob88]

yeah ithink its probably best in the long run. im still waiting on a few geskets and stuff for the m50 manifold so i'll do it before it goes on

[jimbob88]

what size thread is the brown temp sensor ?

[jimbob88]

just a quick update for future reference.
drill and tapped the coolant outlet hole, tap size M14 X 1.5 fits perfect