M60b40 knock sensor

[Gabehada]

So I'm in a pretty strange position. I have my manifold off currently and while I'm here I was gunna change my knock sensors becuase they looked cracked. I went to pick up the sensors from my local auto parts store and the connector was 2prong and mine are 3... so I thought hm oriellys is just dumb. I got home and searched for some online and they're all 2 prong... now I'm worried because I can not find any for sale that are 3 prong and I can't find anyone else who said that their knock sensors are 3 prong... I'm thoroughly confused any insight would be greatly appreciated

[Gabehada]

http://imgur.com/CvrK5RX

http://imgur.com/oHPI3fj

some quick pictures before I can go to my shop and get some clearer ones

[Layne]

I was not aware there were two versions. Both seem fairly common. Search part number 12 14 1 736 303

Put your VIN into realoem.com to make sure you're getting the exact right part number. I used bosch sensors on mine. The only difference is the box they come in, but the price was much lower than BMW (BMW sells bosch).

[moroza]

I thought the 3-prong were for M62, 2-prong for M60. Recall running into this issue years ago and that's what I remember finding out.

[Layne]

I thought the 3-prong were for M62, 2-prong for M60. Recall running into this issue years ago and that's what I remember finding out.

Apparently not. Realoem says the 3 pin is valid up to 4/93, and the 2 pin is valid after that. Considering the M60 only appeared in the US in 11/92, that leaves very few cars with 3 pin.

M62 appears to have 2 knock sensors on a mini harness with a round plug.

[Gabehada]

Thank you all! I found them! That's what's strange I was searching everywhere with my make and model (1994 540i) and all of them were the wrong connector! Thanks a ton

[Layne]

Thank you all! I found them! That's what's strange I was searching everywhere with my make and model (1994 540i) and all of them were the wrong connector! Thanks a ton

What's your VIN? A car made before 4/93 should not be a 94 model. Could be that your engine was replaced with an earlier one.

Or sometimes titles are not done correctly. Mine was made 9/92, but the title says it's a 94. Probably because it's a euro import and the model wasn't available here for 93.

[moroza]

I stand corrected. Here are my notes from 2009:

knocksensors: <4/93 B30 and <5/93 B40 is 12141736303, >4/93 B30 and >5/93 B40 is 12141702163

I think the whole model year thing is idiotic. I was born in September '85, the usual cutoff point for "model year" change. Does that make me a 1986 baby? A car made on 12/31/93 should be a 1993; on 1/1/94 it becomes a '94, end of story. My 4/93 530iT is titled as a 1994 and I once had a bored DMV official get very excited over what they thought was a case of title fraud. :

[Layne]

Of course it's idiotic. It's just a scam to let new car buyers own a "brand new" car for 16 months instead of 12.

Ideally, it would just be sales nomenclature and there would legally be no such concept of model year. Then after 2 years when it makes no flipping difference, you could drop it forever.

[Layne]

The only reason I ask about the VIN, if he has an earlier engine swapped in it might be useful to know when buying other engine parts. If it's just a title issue, then buying parts by the VIN will be fine.

[moroza]

AFAIK the two knocksensors mount to the engine the same way; the difference is in the wiring harness that normally doesn't get swapped when an engine is.

[Layne]

AFAIK the two knocksensors mount to the engine the same way; the difference is in the wiring harness that normally doesn't get swapped when an engine is.

That's true if it were a factory new engine. No one is going to needlessly swap the wiring harnesses on a used engine though. Exhibit A: my 9/92 car now has 2 pin sensors (1995 engine).

[moroza]

No one is going to needlessly swap the wiring harnesses on a used engine though.

Well, I did... but shortly later determined it'd been pointless. I used a <9/93 530iM harness, DME, and whatever style knocksensors it had, apparently the 3-pin.

[ross1]

I suspect the third wire is the shielding.
Also what brand are these sensors from O'Reilly? Given the amount of labor required to swap these and the big box stores proclivity to sell overpriced Chinese replacements for Euro cars you might want to reconsider the purchase and go with OE or something from a well regarded Euro car brand.