E30 Zone

Finally got round to wiring the fan, I have a 90-95 degree temp switch in my radiator which activates my fan. Works fine only the temp gauge is on the 2nd line (a quarter) when the fan kicks in.

Should it not be in the middle? Do I have the correct brown plug in the thermostat, I thought m20 and m20 brown plugs were the same....?

Anyone know what temperature the radiator water is when the needle is sat in the middle on a 325i?

Around 90ish at a guess, but that is just a guess. You do have to change one of the plugs, not sure which one now, but it says in the sticky thread which one.

Is thiis about an m20 or m30 engine??

just wondering as the op mentioned an m20 & it's in the m30 section

sorry it's a useless post op.

mcbonio wrote:I thought m20 and m20 brown plugs were the same....?

I'm guessing this meant 'm20 and m30', that what I took it as anyway.

Ok I have an M30 engine, with an aux fan which comes on at 90-95c. When the fan is activated the needle on the temp gauge is at a quarter.

Shouldn't it be in the middle? This makes me think the brown plug is wrong.

The wiki says "Temp sensor - the brown temperature sensor on the M30 block will need swapping for an E30 (M20 only?)"

How can I tell an m30 brown temp sensor from an m20 one?

Is there a BMW part number stamped on your brown sensor?

will have a look in a sec.!

no part number, just says "MAX 130c"

The reason you have to swap the sensors over is the M30 one has two pins and the M20 only has one pin (could be other way round)
My theory on the gauge is with an 80' stat it sits just over a quarter, with an 88' stat it sits halfway.
Not 100% sure though.

Where have you got you fan switch located?

Fan switch is in the side of the radiator and my brown plug has only 1 pin yet the harness plug has 2 holes...!

I'm guessing it has the m30 brown plug in and needs a 2 pin m20 sensor....

Thought M20 one was 2 pin, M30 was 1 pin

Either way round you must have the right one cos iirc the temp gauge dont work at all with the M30 sensor.

Ill double check mine tomorrow, im saying 1 pin you need.

Please do chaps, if you can just have a little nosey I'd be very grateful.!

Ive got a 1 pin sensor on mine.

Yep - M20 Brown plug has just 1 pin....

Don't forget that the temp gauge is just an indicator and not that accurate - 80 degrees is about 1/4 and 88 is about 1/2 way up as leeparkes rightly states...

Well my radiator switch comes on at 91 degrees, so I know the water temp is 91 when the fan comes on, its just the temp gauge reads 1/4.

Go figure.!

Have you checked the earth nut on the back of the gauge?? These being loose / corroded can give odd readings...