The comprehensive DOHC engine swap thread.

[bmw3er]

As long as the temperature sensors are still installed in the head, all you really need are the two knock sensors, cam and crank position sensors, and Vanos solenoid, if he removed that from the engine.

I believe the temp sensors are still in the head. The vanos solenoid is still there as well, I used the complete S52 vanos system. Is the crank pos sensor on the front or rear of the block on the M50? I know its oppisite on my S52, but now I dont remember which is which.

[FredK]

The CRANK position sensor is on the front on M50, and it's towards the rear of the block on the M/S52.

[BigD]

The cam position sensor is on the front on M50, and it's towards the rear of the block on the M/S52.

Do you mean the crank position sensor? I'm pretty sure the cam position sensor is at the front on my S52. I was just going to ask the same question about the crank sensors. I was in the process of swapping out the oilpan last night and I saw that there is a toothed wheel on the back of the crank, and a sensor that bolts into the bottom of the block in the right place to read the wheel. But on the front of the block, there's the toothed harmonic balancer, and a bracket with a hole for a sensor and a hole for a set screw - typical of the CPS setup I'm used to with M30/S38s. My engine has a sensor in the back but not in that front hole. Do I need something that goes in there?

[325Projectz]

BigD, you need to block that hole if its a OBD2 block.

Crank position goes in that hole on OBD2 motors, and its on the front for OBD1 motors. Cam position sensor is always in the head.

[BigD]

BigD, you need to block that hole if its a OBD2 block.

Crank position goes in that hole on OBD2 motors, and its on the front for OBD1 motors. Cam position sensor is always in the head.

Oh ok, so they just left the front cover and balancer the same for the S52 even though it doesn't need the sensor or the teeth on the balancer?

Yeah, I know the cam sensor is in the head obviously but Fred said that it's in the rear on the S52, the only sensor I could see is on the front, behind the vanos solenoid.

On a side note, I really wish someone would post a big pic of the harness with labels of what's what. If I take a huge pic of the harness spread out, and put in text boxes with numbers beside the leads, can you guys help me fill them in? (ie say #5 is for the CPS, #8 is for the temp sensor)

[FredK]

Well, it's difficult to tell what a connector does just by looking at it.

I just pulled the boot back on each connector, wrote down what colors the wires were, and cross referenced the Bentley for the wire colors. I fixed my post as well, I meant crank sensor, not cam sensor.

[325Projectz]

I figured Fred had a typo, <3.

Best way to do it is lay the harness over the motor and check the plugs by type and length of the wire... Then lookup everything that can go more then one place.

[BigD]

Cool, thanks guys! Sounds like a plan.

[B3M2W5]

Wow so im totaly confused now, I was just wondering if you guys knew what sensors i needed that would have been removed for BMW3ers OBD1 s52 swap b/c my motor is his old one. I can find the part i just need to know what ones I need. I really wouldnt know what was needed for the OBD1 swap for the s52, but I think you guys are tellin me that i need the crank and cam sensor, any one know how much dealer price would be. My guess is either really cheap or really really espensive.
Uhg one more set back after another, hahaha its going to be a long swap once i start haha.

[Lobstrosity]

I'm actually trying to track down the crank and cam sensors as well. Need to hit up some local yards around here, I think. The cam sensor from a 1992 is different from any of the vanos models, which is sadly the one I have managed to find so far. They look pricey (around $120?) each when bought new, but should be reasonable used.

Dmitry, I'm the guy that bought that LSD from you (that sounds bad) back in December. Glad to see you're making some progress! I just need to track down those sensors, and a power steering pump for my M52 (another FYI, M52 power steering pumps are different from M50 power steering pumps), then it's going in the car. Can't wait to get it back on the road.

I used a E36 Bentley and pulled back the connector covers to label the '95 harness I'm going to use, I was able to id everything easily.

[triggrhaapi]

I'm actually trying to track down the crank and cam sensors as well. Need to hit up some local yards around here, I think. The cam sensor from a 1992 is different from any of the vanos models, which is sadly the one I have managed to find so far. They look pricey (around $120?) each when bought new, but should be reasonable used.

Dmitry, I'm the guy that bought that LSD from you (that sounds bad) back in December. Glad to see you're making some progress! I just need to track down those sensors, and a power steering pump for my M52 (another FYI, M52 power steering pumps are different from M50 power steering pumps), then it's going in the car. Can't wait to get it back on the road.

I used a E36 Bentley and pulled back the connector covers to label the '95 harness I'm going to use, I was able to id everything easily.

Why are you using a harness that has connectors that you can't use? You don't have knock sensors and you don't have a VANOS solenoid.

[Lobstrosity]

Why are you using a harness that has connectors that you can't use? You don't have knock sensors and you don't have a VANOS solenoid.

No, I only have a cam sensor from a 1992 is what I was saying. ;) I have a '95 harness and dme, and it's all going on a M52. I need to track down a proper cam sensor and crank sensor.

[triggrhaapi]

Ohhhhhhhhhhh haha sorry I misunderstood.

[triggrhaapi]

No, I only have a cam sensor from a 1992 is what I was saying. ;) I have a '95 harness and dme, and it's all going on a M52. I need to track down a proper cam sensor and crank sensor.

I kinda wish my M52 block didn't end up all jacked up because some idiot took out the spark plugs and left the motor sitting in the rain. The dual knock sensors are a definite improvement over the single one that the M50 has. I kinda liked the oil squirters too. Those both would have been nice for boost.

[B3M2W5]

Ya finding one in a junky yard would be good but i dont think there are any in the yards around where i live just domestic and jap imports (gay)
so im going to have to look elsewere