Location of Crankshaft Position Sensor.

[JPlue]

I couldn't find anything about if those sensors are interchangable, I probably wouldn't try only because if the depths of the sensors are different you could damage the reference pin, flywheel teeth or sensors.

[nando]

jim: what is the sensor on the front of the etas near the crank pulley? it's like hard wired into the car

it's a crank sensor, but it doesn't have anything to do with running the engine. it goes to the diagnostics port.

[kdfwagen]

I couldn't find anything about if those sensors are interchangable, I probably wouldn't try only because if the depths of the sensors are different you could damage the reference pin, flywheel teeth or sensors.

but do you think it is worth changing out the CPS with a new one if it reads 840 ohms?

[kdfwagen]

So there are two sensors on the bellhousing. One upper and one lower. When I look through the hole on the upper I see gear teeth (flywheel?) on the lower I am not sure what I am seeing.. Which one is the CPS? I thought the lower was the CPS?

[JPlue]

it is, the top one is the speed sensor

[kdfwagen]

turns out there was NO ecu in the car... somebody stole it. AHAHAHA....

[StereoInstaller1]

turns out there was NO ecu in the car... somebody stole it. AHAHAHA....

holy shit, that is funny!

[nando]

wow, lol. that's definitely a new one!

step 1 to check for a no-start, no-spark condition: did somebody steal the ECU?

[JPlue]

Haha nice. I didn't even try checking that on mine, maybe I should...

[kdfwagen]

Yeah, the girl I bought it from said. "When I parked it the car was running, but when I came back 2 months later the car would not start". It was a good neighborhood too..

[txtorquemade]

The ECU bandito strikes again. Damn Jlevie didnt even figure on that one.....LOL

[aurelius]

Correct crank sensor for model year 1987 325i

The location of the timing sensors changed with the introduction of the 325is in 9/86. 325e/es cars produced through 8/87 have the bell housing mounted sensors. The SETA cars (9/87-8/88) also have the front mounted CPS. All earlier 325 E30's have the bell housing mounted sensors.

The post quoted above is highly relevant nowadays because there are discrepancies when attempting to sort out which CPS to order for model year 1987 325i (M20B25).

Here's what seems to have happened. As indicated in the quote above, MY 1987 was the crossover year with both types of M20 motors available in the USA. Each of which has a different CPS, mounted in different locations. (MY 87 being production dates thru 8/87)

Also, in late 2013, the part number (12141720852) for the front-mounted 325i CPS changed. It is now 12141720856. But there are no clear indications as to which models it fits (realoem).

Many parts sellers still use the older part number.

Making things worse, nearly all the fitment charts and diagrams (including realoem) indicate 1987 models need part number 12521279695. It is sold (OE BMW) in the form of a pigtail. Which I was aware of prior to purchase and I was not happy about the prospect of splicing such a crucial sensor wire but all info indicated this is what I needed. Well, it wasn't. I think 12521279695 may be the sensor mentioned in post #17 within this thread. And I don't think (?) the '87 325i even has one.

Anyhow, I ended up getting an aftermarket version of 12141720856. The brand is Facet and the packaging indicates made in Italy. Plastic sensor body vs metal in the OE version. It was sold under the older part number (-852).

There are at least 2 additional after market brands available. What you find will depend upon which of the 2 part numbers is searched.

Bottom line: you will have trouble figuring out which CPS you need for an '87 325i. But based on my personal experience, '87 325i uses the front-mounted CPS which the parts diagrams indicate is for 325i model years 1988+.

I installed it and it works perfectly.