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Hey how is it going? I’m new here I recently bought a 2006 bmw m5 e60 and I changed the clutch and the flywheel on it but before I changed it was working after my mechanic replaced everything the car cranks but doesn’t start please help
 

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He mounted the flywheel in the wrong position on the crank. There are 9 ways it can be mounted, but only 1 is correct. The TDC is incorrect for timing.
 

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He mounted the flywheel in the wrong position on the crank. There are 9 ways it can be mounted, but only 1 is correct. The TDC is incorrect for timing.
I agree with the captain that there is 1 correct way, but I’m not quite sure that yours is indeed mis-mounted. There is a boss/pass through on one of the holes in the crank flange, this is designed to mate up with the corresponding recess on the backside of the flywheel. This is for error-proofing. You really have to screw this up to mis mount it in any of the other 8 orientations, unless he removed that boss, which is not easy to remove as it’s pressed in. You won’t be able to fully torque down the crank bolts, it won’t seat flat, the holes won’t line up and be square to the flange, etc. I replaced my flywheel and starter a few weeks ago, here is a pic. Look at the 11 o clock position. I can’t rotate the photo. 12 is on the left lined up with the starter.

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As for the start, but no run condition. I encountered that on the SMG as well after I did rod bearings. I thought it was lack of fuel pressure, so I monitored that with ISTA, and it was fine. I thought battery was fine since voltage checked out, but was on the lower side. I put in a newer known good battery and it started up fine. I have a battery tester and it did diagnose the battery as having only 330 CCA. With the E60 M5 it seems that weak battery’s can crank the car but the current draw will pull the voltage down too much that the DME won’t turn on the injectors. You could simply have a weak battery. Try jump starting your car.
 

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For whatever reason the smg flywheel can indeed be mounted in the wrong orientation. I think the boss mates with another hole and even tho holes are slightly mis aligned bolts will go in. There's been at least a couple reports of this happening. But try simple things first like jump starting, check fuel and ign, etc.
 

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For OP I would only ask the mechanic to drop the trans and remove the clutch and flywheel as a last resort after fully diagnoising other possible causes. There seem to be lots of no start failure modes with SMGs. It’s a POS system, great in S5/S6 but otherwise crap and lots of headache and costs. Depending on how much of the car was already put back together, you might be billed another 800-1000 to remove the flywheel only to find out that it was installed correctly.

It could be that pre LCI cars didn’t have the dowel and recess, Troy would know for sure, he’s been run off this forum. this is a pretty common design methodology, it’s not unique to BMW. Any experienced mechanic should easily see and figure this out. If it CAN be misinstalled then it is not error proofed by definition. Modern assembly plants are designed to move fast, prevent, and detect errors in station. That’s the only reason why both these features exist on both mating parts. It does add to the part cost to add these machining operations. I’d like to see the threads where ppl have mis-installed the flywheel. The clutch is very easy to install incorrectly, but NOT the flywheel, unless the through dowel is not present. I may try this out on my spare engine and old flywheel.

The battery thing was a bit surprising to me and I would say it would not be intuitive or obvious for a mechanic, most cars will either not crank or have degraded cranking on a low batt. It is odd that my car would and could keep on cranking but not start. This must be a software routine to not enable the injectors to open. The current and voltage to open them is minimal.
 

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Discussion Starter #6
He mounted the flywheel in the wrong position on the crank. There are 9 ways it can be mounted, but only 1 is correct. The TDC is incorrect for timing.
It could be what you saying I’m not sure because I wasn’t there when my mechanic mounted on the car
 

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I agree with the captain that there is 1 correct way, but I’m not quite sure that yours is indeed mis-mounted. There is a boss/pass through on one of the holes in the crank flange, this is designed to mate up with the corresponding recess on the backside of the flywheel. This is for error-proofing. You really have to screw this up to mis mount it in any of the other 8 orientations, unless he removed that boss, which is not easy to remove as it’s pressed in. You won’t be able to fully torque down the crank bolts, it won’t seat flat, the holes won’t line up and be square to the flange, etc. I replaced my flywheel and starter a few weeks ago, here is a pic. Look at the 11 o clock position. I can’t rotate the photo. 12 is on the left lined up with the starter.

View attachment 938820
As for the start, but no run condition. I encountered that on the SMG as well after I did rod bearings. I thought it was lack of fuel pressure, so I monitored that with ISTA, and it was fine. I thought battery was fine since voltage checked out, but was on the lower side. I put in a newer known good battery and it started up fine. I have a battery tester and it did diagnose the battery as having only 330 CCA. With the E60 M5 it seems that weak battery’s can crank the car but the current draw will pull the voltage down too much that the DME won’t turn on the injectors. You could simply have a weak battery. Try jump starting your car.
I’m try to tell him to check my battery first thanks for the help
 

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Discussion Starter #8
For OP I would only ask the mechanic to drop the trans and remove the clutch and flywheel as a last resort after fully diagnoising other possible causes. There seem to be lots of no start failure modes with SMGs. It’s a POS system, great in S5/S6 but otherwise crap and lots of headache and costs. Depending on how much of the car was already put back together, you might be billed another 800-1000 to remove the flywheel only to find out that it was installed correctly.

It could be that pre LCI cars didn’t have the dowel and recess, Troy would know for sure, he’s been run off this forum. this is a pretty common design methodology, it’s not unique to BMW. Any experienced mechanic should easily see and figure this out. If it CAN be misinstalled then it is not error proofed by definition. Modern assembly plants are designed to move fast, prevent, and detect errors in station. That’s the only reason why both these features exist on both mating parts. It does add to the part cost to add these machining operations. I’d like to see the threads where ppl have mis-installed the flywheel. The clutch is very easy to install incorrectly, but NOT the flywheel, unless the through dowel is not present. I may try this out on my spare engine and old flywheel.

The battery thing was a bit surprising to me and I would say it would not be intuitive or obvious for a mechanic, most cars will either not crank or have degraded cranking on a low batt. It is odd that my car would and could keep on cranking but not start. This must be a software routine to not enable the injectors to open. The current and voltage to open them is minimal.
Thank you for you help
 

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they usually have a big jump starting charger, anything that will allow the electrical system to maintain 12.6V or more during the start.

I seem to recall that ISTA was displaying 11.6V for me and it was cranking fine, but I’m sure the current draw pulled the voltage draw down. I use ISTA with a real ICOM so I get a real voltage display, using a K+DAN cable will not show voltage in ISTA.

Here is a pic of the back of my old flywheel (2008). Notice at the 12:00 position the hole is larger because of the through dowel. If the dowel was NOT on the crank flange, it would not bolt on. The flywheel absolutely will not seat flush with the flange, as such you will not be able to start let alone run down the flywheel bolts because they will cross thread or not even engage. The flywheel bolts are captured within the flywheel assembly, meaning they are not separate bolts. If you try to force the bolts to start, like just trying to run it down with an impact you will damage the threads on the crank flange. That would be GAME OVER, new engine (you’d need to get a new crank at a minimum).
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I just tried to remove the dowel and it actually does come out with pliers. The hole on the crank flange is bored out but only 2.5mm so indeed it could have come off or seized itself to your old one when pulled off. That’s probably what’s happend with the captain’s car.

Ask dude to look at the old flywheel and see if it’s there. I’d still be reluctant to drop the trans again unless there is a code that in fact indicates some issue with the crank signal or position.

See pic. the hole with the yellow marks is the one (one on the far left), dowel was pulled.
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I was thinking more about this while working on the car. You may be able to figure out if your flywheel is installed Correctly by rotating the flywheel with the crank sensor out of the hole. There is a gap on the pattern exactly in line with the big hole. So if you do research you can figure out which cylinder is at TDC when the gap is in the crank window, you can rotate the crank there and check. If it matches then you are set. This is pretty easy, you just have to research what cylinder is at TDC when the gap passes the window and then pull the right spark plug to check for TDC. This shouldn’t take more than 30-60 min, much better han dropping the trans and fflyw

also when looking at the flywheel as installed “the pattern” in the circle is where the boss should be. However, without doing the above you’d have no idea where the crank is.

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