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Every once in a while it will stumble on the first crank for one turn. Hardly any signs of combustion. It usually is just the exact same noise no matter what.Comment
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Yeah, I mean the last diagram in the post I linked a few posts up. The crank damper wheel is the big toothed thing that sits behind the big pulley that drives all of the belts. The crank position sensor is mounted in a little bracket at the bottom passenger side of the engine, sort of under the AC compressor. It points straight at the damper wheel and should be like 1-2mm away from the tips of the teeth.
You can see it in the linked image. The damper wheel teeth are visible behind the pulley at the bottom of the "triangle" formed by the belt. The position sensor is the little silver cylinder pointing at it in the very bottom middle. One of the teeth in the wheel has a small notch in it that should align with the arrow in the oil filter housing. You will also notice a 2 tooth gap where teeth are missing. You may need to remove the cooling fan to see all of this clearly.
If the crank position sensor is too far from the wheel's teeth or the wheel got installed in the wrong orientation somehow (which might indicate that a couple of other odds and ends are missing) then you would get a condition where you either have no spark, or the spark is timed totally wrong and isn't igniting any air-fuel mixture.
Here's a diagram of the parts related to the damper wheel's orientation.
http://www.realoem.com/bmw/enUS/show...diagId=11_4319
Part 8 slides onto the nose of the crank, and part 9 (the little woodruff key) holds it in alignment. However, part 8 slides past the key so that a bit of it sticks out still, so the key also aligns part 6. Part 6 has the pin, part 7, in it and that is what part 1, the damper wheel, aligns to. Sorry if that is a bit drawn-out. Anyway, it is possible to forget part 9, which ultimately means that the damper wheel is not aligned with the crank properly (the gap at the missing teeth is more or less what tells the ECU where TDC is), and the ECU will have bogus ignition timing. The crank damper wheel is the single most important element in the ECU's list of inputs because crank position and RPM are measured from it.
Missing the key is not all that big of a deal, mechanically, because it only aligns things during assembly. The big 22mm bolt (part 4) in the nose of the crank is torqued to 240 ft-lbs, and that squeezes parts 5, 6 & 8 against the crank with sufficient force that they do not slip (and it would be VERY bad of they did because the cams and crank would get out of whack and send valves into pistons).
A) If the woodruff key is missing, then you have to do some shitty work to make this right. You either have to open up the timing case, take the chain off and replace the key. You could alternatively try loosening the big bolt and rotating the damper wheel into the right position by visually aligning the teeth to match my diagram without opening things up. Either way, the big ugly bolt with 240 ft-lbs on it has to get loosened and re-tightened, and the tightening process would probably get things out of sync.
B) If it is just the little pin (part 7) that is missing, you just have to undo the 6 13mm bolts that hold the damper wheel to part 6 and align things without taking the timing covers off or anything. That's a fairly easy 1 hour job if you have a replacement pin or metal rod of the right diameter.
Who reassembled this engine, BTW?Comment
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Okay that was intense haha. I'll probably have to dive into that this weekend and see what is going on.Yeah, I mean the last diagram in the post I linked a few posts up. The crank damper wheel is the big toothed thing that sits behind the big pulley that drives all of the belts. The crank position sensor is mounted in a little bracket at the bottom passenger side of the engine, sort of under the AC compressor. It points straight at the damper wheel and should be like 1-2mm away from the tips of the teeth.
You can see it in the linked image. The damper wheel teeth are visible behind the pulley at the bottom of the "triangle" formed by the belt. The position sensor is the little silver cylinder pointing at it in the very bottom middle. One of the teeth in the wheel has a small notch in it that should align with the arrow in the oil filter housing. You will also notice a 2 tooth gap where teeth are missing. You may need to remove the cooling fan to see all of this clearly.
If the crank position sensor is too far from the wheel's teeth or the wheel got installed in the wrong orientation somehow (which might indicate that a couple of other odds and ends are missing) then you would get a condition where you either have no spark, or the spark is timed totally wrong and isn't igniting any air-fuel mixture.
Here's a diagram of the parts related to the damper wheel's orientation.
http://www.realoem.com/bmw/enUS/show...diagId=11_4319
Part 8 slides onto the nose of the crank, and part 9 (the little woodruff key) holds it in alignment. However, part 8 slides past the key so that a bit of it sticks out still, so the key also aligns part 6. Part 6 has the pin, part 7, in it and that is what part 1, the damper wheel, aligns to. Sorry if that is a bit drawn-out. Anyway, it is possible to forget part 9, which ultimately means that the damper wheel is not aligned with the crank properly (the gap at the missing teeth is more or less what tells the ECU where TDC is), and the ECU will have bogus ignition timing. The crank damper wheel is the single most important element in the ECU's list of inputs because crank position and RPM are measured from it.
Missing the key is not all that big of a deal, mechanically, because it only aligns things during assembly. The big 22mm bolt (part 4) in the nose of the crank is torqued to 240 ft-lbs, and that squeezes parts 5, 6 & 8 against the crank with sufficient force that they do not slip (and it would be VERY bad of they did because the cams and crank would get out of whack and send valves into pistons).
A) If the woodruff key is missing, then you have to do some shitty work to make this right. You either have to open up the timing case, take the chain off and replace the key. You could alternatively try loosening the big bolt and rotating the damper wheel into the right position by visually aligning the teeth to match my diagram without opening things up. Either way, the big ugly bolt with 240 ft-lbs on it has to get loosened and re-tightened, and the tightening process would probably get things out of sync.
B) If it is just the little pin (part 7) that is missing, you just have to undo the 6 13mm bolts that hold the damper wheel to part 6 and align things without taking the timing covers off or anything. That's a fairly easy 1 hour job if you have a replacement pin or metal rod of the right diameter.
Who reassembled this engine, BTW?
The mechanic who had the car last reassembled it - he may have missed something. Sucks for me.
I'm thinking that this has to be the issue, as we have discovered previously - everything else seems to be working just fine.Comment
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Yeah, sorry about the long post. A comfy couch plus a beer sometimes leads to a longer-than-expected post lol.
Anyway, yeah, if it is not that then I have no idea what it could be. This is already one of the most lengthy "M42 no start" sagas that I have ever seen!Comment
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Okay, quick question for you.
How do I make sure that part 7 is oriented correctly?Last edited by theTBLACK; 06-07-2016, 06:54 AM.Comment
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As far as I can recall, there is only one spot in the hub/flange that it can go.Comment
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Yeah, hopefully. That big 22mm bolt is a real pain in the ass. If the woodruff key is missing, you can't use the starter to break it loose either because the crank would stop driving the chain sprocket once the nut comes loose and you'd have pistons hitting valves, so you will need a crank locking tool and a very large breaker bar in that case.
Good luck. Hopefully it is the pin or sensor.Comment
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Also, is this the crank locking tool?
http://www.pelicanparts.com/More_Inf...2011%202%20300
If so, I have it.Comment
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The pin goes into the drive flange that mounts on the nose of the crank. The chain sprocket is behind that. The pin inserts into the drive flange. Said drive flange has 6 M8 threaded hols which the damper and accessory pulleys bolt to. There is a 7th hole which is for the alignment pin. You can't put it in wrong.
Yes, that is one of the types of locking tools. You have the stock M42 flywheel, correct?Comment
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I double checked - The timing is spot on. At least I think it is. Photos for reference.
I also looked at the resistance on the CPS - it looks like it's low - 1000 as opposed to the 1150-1400 as noted by the manual.
Could this be a possible culprit? But as you mentioned previously, with the car getting spark, it is probably working.
Last edited by theTBLACK; 06-07-2016, 07:44 PM.Comment
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