M30 help

Sat Sep 30, 2006 8:04 pm

another case of believing the e30.de errors there andy! i must admit i would have cut mine unless someone (may have been bigdek?) had pointed that out!

Mon Oct 02, 2006 8:13 pm

where is the m20 temperature sender supposed to be used? in the thermostat housing? or in the radiator and which color plug goes to the temp gauge. mine isn't working and the constant heater is gettin old as a safeguard...

Mon Oct 02, 2006 8:23 pm

The M20 sensor you need is the brown one with a single pin connector.
The black two pin plug goes to this - will only fit one way.
It goes in the thermostat housing nearest to the top hose.

Mon Oct 02, 2006 8:24 pm

yup, what he said!

Sun Oct 08, 2006 5:01 pm

you sure its a single pin? i have one with 2 pins on it and then i have a black on that is a single pin

Mon Oct 09, 2006 12:30 am

You wont have to use an M20 one mate, just use your original sensor out of your M40 engine - it will match your instruments.

Mon Oct 09, 2006 2:51 am

i had an m20 engine in before. the problem is i'm using a 87 325 I harness because my pre facelift e30 didn't match up with the e34 plugs as it was a drive by wire throttle. so i had to convert the harnesses. i've tried reusing th stock e34 sensors but it obviously doesn't work so i'm wondering if it would with the m20 sensors and which one i need to put in. i h\\

Mon Oct 09, 2006 5:18 am

ah sorry mate, got you mixed up with Twiggy - yes I know about the drive by wire harness - I couldnt use mine either. Yes, so you will need to use the M20 sensor. You may have to modify your connector though - my connectors dont match but it still makes contact and I then just siliconed the connector so it doesnt fall off (like it did once before and nearly caused me to cook my engine!)

Tue Oct 10, 2006 12:34 am

will the m30 front of the prop bolt onto the rear of a m20 325i prop?

Tue Oct 10, 2006 12:45 am

does anyone know why the m20 sensor has to be used? i would assume a temp sensor is a temp sensor.

Tue Oct 10, 2006 12:56 am

The M30 fron part of prop (shortened to the correct length for engine position) slides onto the rear half of the M20 prop with no modification.

I think the temperature sensor has to match the M30 electrics, or maybe the clocks. So if you start with a set of clocks from a 4-cylinder car the white plug thing on the front of the clocks set has to be changed anyway for a 6-cylinder one or the rev-counter will read 50% too low.

Tue Oct 10, 2006 12:00 pm

The M30 fron part of prop (shortened to the correct length for engine position) slides onto the rear half of the M20 prop with no modification.

There must be 2 different types of props - that is also what the jarad squires site said - but aint no way in hell the M30 front half was going to slide into my E30 rear. I had to cut the uni joint out of both halves and then reconnect them with a new uni joint.

Tue Oct 10, 2006 8:22 pm

the E34 M30 prop i had for a while definately does not mate to a E30 M20 one. in the pic, both props are lined up at the gearbox flange for comparison. the E30 prop has a splined coupling, the E34 one has a bolt up flange.

more pics here that could answer some questions
http://smg.photobucket.com/albums/v382/ ... onversion/