how many sensor attach into the m20 thermostat housing ?

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markus_74
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Post Sun Jul 27, 2014 12:40 pm

hello,

I want to replace all sensor in my engine 325i motronic 1.3 1989-1991.

I have search in the wiki but can not find how many sensor attach to the thermostat housing?

I see at realoem that it is said 2 but in the other website I found 4 sensor.

ENGINE COOLANT TEMP SENSOR 1-POL 12621710512

Temperature sensor M12X1,5 13621709966

and

what is different between oil pressure switch for 325i with catalytic converter and without? which should I use?


03 OIL PRESSURE SWITCH M12X1,5 12/1986 61311354274 $14.96 Cat=Yes, +core
03 OIL PRESSURE SWITCH M12X1,5 1 61311354274 $14.96 Cat=No, +core
03 OIL PRESSURE SWITCH M12X1,5 1 12/1986 12611710509 Cat=Yes, +core, ENDED
03 OIL PRESSURE SWITCH M12X1,5 1 12/1986 12617568480 Cat=Yes, +core, ENDED

03 OIL PRESSURE SWITCH M12X1,5 1 12/1986 12617620512 Cat=Yes, +core, ENDED


Thank you before
markus
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gromgsxr
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Post Sun Jul 27, 2014 12:56 pm

should be 2 sensors, blue 2 pin for the ecu and brown 1 pin in connector for the temp gauge.
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Brianmoooore
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Post Sun Jul 27, 2014 3:54 pm

Number of sensors depends on the car's intended market. All should have the blue and brown, but some have an excess temp. switch as well, linked to the overhead panel.
The only variations I know of in oil pressure switches is the differing connector between pre and post facelift versions.
You're making a mistake replacing good sensors. A twenty year old good one is likely to be more reliable than a new one. These things follow a 'bath tub' reliability curve, where the twenty year old ones are mainly right in the bottom of the tub, while a new one is sitting on the rim.
Grrrmachine
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Post Sun Jul 27, 2014 4:36 pm

Brianmoooore wrote:These things follow a 'bath tub' reliability curve, where the twenty year old ones are mainly right in the bottom of the tub, while a new one is sitting on the rim.
Care to put that into words us mere mortals will understand? :D
markus_74
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Post Sun Jul 27, 2014 4:52 pm

Brianmoooore wrote:Number of sensors depends on the car's intended market. All should have the blue and brown, but some have an excess temp. switch as well, linked to the overhead panel.
The only variations I know of in oil pressure switches is the differing connector between pre and post facelift versions.
You're making a mistake replacing good sensors. A twenty year old good one is likely to be more reliable than a new one. These things follow a 'bath tub' reliability curve, where the twenty year old ones are mainly right in the bottom of the tub, while a new one is sitting on the rim.
hello, brian

so if it is still good do not replace? I think the older the sensor will be worst.

thank you for the info.
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Post Sun Jul 27, 2014 9:14 pm

Grrrmachine wrote:
Brianmoooore wrote:These things follow a 'bath tub' reliability curve, where the twenty year old ones are mainly right in the bottom of the tub, while a new one is sitting on the rim.
Care to put that into words us mere mortals will understand? :D
The one sat on the rim is waiting to take a plunge!

As the actress said to the bishop....
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reggid
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Post Sun Jul 27, 2014 11:21 pm

i bought a new sensor and it shit itself in a week, kept flashing at me and leak out between the metal and plastic.
if you need a new one get the expensive replacement one not the one that cost about $5-10 (i.e. NOT FAE brand).

i now use a VDO one which can be hooked up to a gauge but it also keeps the dash light operational. Now the light on the dash comes on at a higher pressure (13psi vs 7psi) than the OEM one which is a little bit more of a warning.
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markus_74
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Post Mon Jul 28, 2014 4:19 am

reggid wrote:i bought a new sensor and it shit itself in a week, kept flashing at me and leak out between the metal and plastic.
if you need a new one get the expensive replacement one not the one that cost about $5-10 (i.e. NOT FAE brand).

i now use a VDO one which can be hooked up to a gauge but it also keeps the dash light operational. Now the light on the dash comes on at a higher pressure (13psi vs 7psi) than the OEM one which is a little bit more of a warning.
hello, reggid

i found some brand febi, behr, and gates for sensor and thermostat 80 does is it very good?
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reggid
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Post Tue Jul 29, 2014 3:40 am

behr is usually a good brand
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