ive read every thread I could find on timing this thing and every one say that when you find the hole in the flywheel you are at 90 degrees btdc. I've rotated mine several times and checked my piston depths every time my locking pin drops in and without fail, 1 & 4 are down and 2 & 3 are up. Where do I go from here? I would think the flywheel and the pistons are locked in motion together so was my flywheel just installed in he wrong spot relative to my pistons? I get the cams getting off from the crank and understand using the locking tools to reset them. I need to make sure my crank is actually In the right place before I chain it back to the cams and I'm not sure how I would correct it if the flywheel hole is wrong

 

I put dowels in the spark plug holes and mine were even when the pin was placed in. Are you the first owner? Has your flywheel been removed? You're absolutely certain the pin is fully in? Pull it out and verify with a pin or pick.

 

The text on the cams should be on top when the cylinders are even.

 

I don't know for sure, since I have not removed the flywheel, but could there be more than one alignment hole?

 

I bought it in February and the chain broke in April, I was thrilled. Have for kids in sports so I've been tinkering with it in my spare time after a local shop quoted me 4400 without even removing the valve cover. The top chain guide shattered and the chain was actually off the vanos sprocket so I knew I would have to realign the cams with the alignment tools which was no big deal. When turning the engine manually however and monitoring the pistons, every time I hit the flywheel hole the pistons are as described before. I can tell the car has been worked on before so it is possible the flywheel was removed

 

Actually I did remove it once. Can't find a picture of it though. I really can't recall if there is a way to re-attach the flywheel so that it would be about 180 degrees off or so. When you did the re-alignment of the cams and chain, did you pin the flywheel. I'm going to just brainstorm with you and perhaps someone else will chime in. Also I don't know if damage has been done to valves and so on. The first question to me is can the flywheel be installed so that the pinhole is in the wrong place. If there is no alignment key then I suppose yes. If that is the case then the flywheel needs to be repositioned. The problem is that would not get the pistons into all at the same position. Trying to force any of that into position is not a good idea. I can't get around getting the position correct easily. Somehow you'll need to get the flywheel alignment corrected with the cylinder piston positions. Perhaps remove the head so the valve setup if correct doesn't conflict. Problem that won't change your alignment with the pistons. And you've determined that when all cylinders are even there is no alignment hole. If your not sure then I'd pull the engine. Remove the head. Remove the flywheel. Rotate the cylinders to their correct alignment. Re-attach the flywheel with the pin alignment hole at six and the tool in position. Then re-attach the head and re-do the chain installation procedure. I'd verify the cams are truly as the should be in the locked position with the text dead center and top. Re-do all the chain fit procedure. I just think something either got way off when the chain slipped off and somehow perhaps if possible your flywheel was attached without using an alignment pin during a clutch job. Any thoughts?

 

If you're convinced there is no interference. You could do a clutch job. Drop the subframe remove transmission. Rotate by hand the cylinders to the correct position. Remove flywheel. Then if everything looks approximately okay put the flywheel back with the pin to help you line up. With the flywheel and pin now in place and the cylinders in the correct position check your cams if the text is not on top exactly do a timing adjustment procedure locking the cams and so on. Can't think of any other way. This or the other. Neither is big on money just time.

 

Looking at the bolts from the trans to the engine, I'd say it has def been removed for a clutch or something prior to me purchasing it. I think your right about dropping the trans and rotating to 90 degrees and then trying to reposition the flywheel with the hole at 6 o'clock. Or.... shortcut, I could rotate to 90 degrees and drill a new notch in flywheel for the pin and reassemble from there, just not sure if that would throw the balance off and cause vibration

 

Here's a pic of my OEM '07MCS flywheel. Note three evenly spaced holes around the perimeter, at a slightly different radius than the locking pin hole. Also note the crankshaft bolt holes --- six are for mounting bolts, and the seventh one is for a dowel --- item 6 in this RealOEM pic --- http://www.realoem.com/bmw/enUS/show...diagId=11_3919 If the car was running after you bought it in Feb, then the dowel pin must have been in place. If you never had it running, or had it apart during your "tinkering", it's possible the dowel pin wasn't installed during the last assembly.

Also, if you're not using a legitimate flywheel locking tool, i.e., a short screwdriver, it might be possible to reach one of the three "other" holes, and simulate a locked condition --- there's not much difference in the holes' radius from center. Remember, the crank turns twice for every cam rotation, so it's possible for the crank to be on the "wrong" rotation during assembly. However, this "wrong" rotation should still have all pistons at the same height, just cam position will be 180 out. That's why cam labeling location is important.

Finally, if the chain broke wile the engine was running, this is an "interference" engine --- valves can hit pistons if not timed correctly. You should pull the head to ensure no damage to the pistons or valves. I wouldn't trust a borescope.

So, questions I have are ---
What model / year are we talking about?
Have you ever had the engine running?
Did your "tinkering" involve taking the flywheel off?
Are you using a proper flywheel locking tool?
Are you prepared to take on a project like this?

 

I thought there were other holes back there, but didn't have a picture for sure. It sure looks possible to lock it at a position other than the cylinders at 90. At any rate it is solvable. I understand the car was running for a few months. If the head is removed and you turn the cylinders to 90 and find that the alignment pin hole is correct your job just got easier. And you could check for damage to the valves and pistons. If everything is okay you can button it up.

 

Absolutely do not drill.

 

Ran perfect for two months besides throwing a code for thermostat. One day it started the death rattle when I started it, and then went away as I was under the hood trying to trace the noise. Drove it 20 miles with no issue and then it just died with no loud noise or binding and I coasted into gas station. Towed it home, researched and learned about the timing chain issue, pulled the valve cover and my top guide was shattered and the chain was off the intake cam. I have the locking tools for the cams and flywheel but like I said, the engine was turning when the chain off the intake cam but that's no big deal since I just rotate them to the upward position and install the cam locks. My only issue is getting the pistons in correct position when flywheel is locked. The fact that it didn't make any metal on metal noise when it died makes me feel confident the internals are fine. Just need the timing to be right when I close it up so I don't have to take all this crap off again... or burn it, whatever lol

 

The problem is rotating the crankshaft with the head on if they are not correctly in sync with the cams and valves. You could end up bending the valves or damaging the pistons. The safest approach is to remove the head and then get the crank and pistons in position. Just my opinion. You want to be sure. If the engine is okay still now you don't want to mess it up.

 

If when you have the head off and still can't find the pilot hole on the flywheel then you'd need further disassembly.

 

GOldbrokenwind,
07 MCS
yes
no, valve cover and removed timing chain assembly
yes
and too late to prepare lol

 

The locking pin wouldn't fit into bore at first, after reading a thread on here I sanded it down slightly and it slid into the bore, rotated until it dropped into the flywheel further which should have meant he flywheel was locked, which it was, and the pistons were even, right? Removed spark plugs and checked piston height to be sure and they were not even. Pulled the locking pin and rotated further and every full rotation it drops in agian into the same location with the pistons also in the same location.

If if there is a dowel on the flywheel then I assume whoever worked on the transmission could not have put it on clocked one hole over causing the locking pin bore to not align the pistons, which sucks because that is the only explanation I could come up with.

I really don't want to drop the trans to get to the flywheel, if there is only one way to possibly put it on then I don't see how it could be the problem

 

When I put the alignment tool in my flywheel it was not easy to push in. Also I believe I felt the other holes as I turned. My method for finding the hole was to put equal length dowels in through the sparkplug holes. It allowed me to see when I was approaching the hole I needed.


Not from doing a clutch job, but cleaning valve intake and exhaust ports.

 

I remember reading about somebody setting their timing without using the locking pin. Maybe it was on this car. If the flywheel is installed without having the crankshaft dowel pin installed first, then there are six different positions it can be mounted --- only one of which will be correct. Crankshaft orientation is only significant for setting timing with the built-in pin hole location.

On a side note --- my OS Giken clutch flywheel was one of the last ones produced without this locking pin hole. That's why a have an OEM unit --- to set timing. It's scrap flywheel, donated by a friendly service tech. PITA to use it but I'm right-on with timing, and I've used it twice. It's possible your '07 MCS got an even earlier OS Giken unit and he tried to drill his own pin locking hole --- & screwed it up!

One other very remote possibility --- connecting rods are broken and the pistons aren't moving. If you've seen your "measuring rods" move up and down, then there's probably no rod damage.

You can take your chances and set timing without the flywheel locking pin, but there's no way I'd recommend it. Be advised that there are four different times in one complete engine CYCLE (not rotation) the pistons are all the same height --- 90 deg BTDC and ATDC. You gotta watch for #1 piston to be rising, not falling, if you want BTDC, and it's gotta be CW rotation, monitored from the chain end. Altho, during engine assembly, either of the two conditions where #1 is rising will work, you just gotta set the cams properly (labels up). Safest way is to disassemble tranny from engine and ensure the crankshaft / flywheel dowel is in place. Then if it's an OS Giken, compare the locking pin hole location (with respect to crank dowel pin location) with the pic I sent earlier.

 

Oldbrokenwind, I think you've covered it as thoroughly as it can be. Playing it safe only costs time and a little money.

 

What I'm seeing when I hit the hole. As I rotate 1:4 move together and 2-3 together and end up back here when I hit the hole again. Looks like I have more disassembly which sucks but I do enjoy learning about my engine so Here we go! Lol thanks for the help guys, and I'm sure I'll have plenty more questions for ya so please stay tuned

 

with the cams locked, were you able to rotate the engine freely 360 deg?

 

No I had to take the cam locks off to make full 360 rotation

 

ok good...are you locking/trying to lock the crank first then lock the cams? what is the flow of steps you're following.

 

Your last pic shows no chain installed. Since this is an "interference" engine, rotating the crank with the cams installed and no chain, there's a risk of the pistons running into the valves. I highly recommend you at least loosen, if not remove, both cams enough so the valves are not opened fully. This is probably why you couldn't rotate the engine with cams locked --- pistons hitting valves. As long as you didn't force the engine rotation, there shouldn't be any damage. To ensure no valve damage, do a compression test after re-assembly.

Now, loosening the cams is another issue --- differing valve spring tension tends to bend the cam. Without the special tool, you need to loosen each cap gradually, so the caps minimize the cam "bending". Same process when re-installing cams.

As MiniToBe asks, the process flow is critical when playing with cam timing. This is another reason I always recommend the DIY'r start with a Bentley manual. It's not the easiest manual to follow, but the necessary info is there. In your case, you'd already started.

Back to the beginning --- you said the top chain guide "shattered". In all probability, there are chain guide parts floating in your oil pan. Have you dropped the pan to clean it out? Have you replaced the other guides. Since timing chains / guides are common failures, there are kits available with most of the necessary parts. Big cost savings over buying individual pieces. Your original quote of 4400 wasn't a bad price --- it's not an easy task.

 

Yeah I never forced it figuring there were pieces of the guide in the oil pump chain, then realized it was likely a valve open. I did drop the oil pan and cleaned out pieces from the pump housing and strainer. Bought the chain kit with new tensioner and guides, along with a new vacuum pump, thermostat, water pump, crank pulley, and belt. After talking about dropping the tranny and checking the clocking of the fly wheel I ordered the Bentley manual and it will be here tomorrow