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Timing Help

914 views 4 replies 3 participants last post by  Burnout_187 
#1 ·
So I started tearing down my 2003 engine after losing oil pressure and finding big chunks of the chain guide plastic in the lower sump. One piece of plastic was wedged in the oil pickup so I think it may have been restricting the oil flow and causing the oil pressure light to come on. Everything has gone well so far - valve covers are off and I am trying to get the engine to TDC. The engine ran (with some horrible diesel sounding chain slap on the passenger side vanos) before I started this, so I don't think the chain had skipped. That said, as I am hand cranking the engine clockwise (with plugs removed), it seems to bind up after one full revolution. Same happens in the counter clockwise direction. I am able to get it turned over so the hole in the vibration damper lines up with the lock flange, but at that point the cam marks are not lined up (granted I suppose because of vanos that isn't necessarily a given). A couple questions:


1. Is the S62 an interference engine? I've seen conflicting posts on this, but since the car started and ran (other than the chain slap) I don't think I had a valve to piston crash.


2. I'm assuming w/o the plugs in place, it should be pretty easy to turn over so the binding has to be something internally (and no I didn't drop anything into the engine). I can crank one full revolution before it binds up so I'm thinking that some more of the broken chain guide is stuck on the chain itself somewhere and that's causing the binding. I'm assuming not to try and force it to keep turning.


3. If I line up the hole in the vibration damper with the locking flange, should the 4 cam marks line up, or is that only on every 4th revolution? Or do I need to put the TDC pin in place and then move the cams to get the marks lined up before locking?


4. Since I can't seem to get the lock pin to line up at the same time as the cams, how should I proceed to take the vanos units off to get the chain covers off and see what the hell is going on inside the chain? In other words, if god forbid it did skip, can I proceed to take the vanos units off without locking the cams? How difficult would it be to retime the engine and set the cams correctly if I didn't lock them?


At this point I haven't ordered any parts, I'm still in tear down mode to see what's going one. The good news so far is I didn't see any metal or plastic on the visible parts of the chain or cams. The cam lobes show some wear but no major burning or obvious damage. The plugs and piston tops had a decent amount of carbon build up and I just started getting a AA fault before all this went down. As always any thoughts or help is appreciated.
 
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#2 · (Edited)
So I started tearing down my 2003 engine after losing oil pressure and finding big chunks of the chain guide plastic in the lower sump. One piece of plastic was wedged in the oil pickup so I think it may have been restricting the oil flow and causing the oil pressure light to come on. Everything has gone well so far - valve covers are off and I am trying to get the engine to TDC. The engine ran (with some horrible diesel sounding chain slap on the passenger side vanos) before I started this, so I don't think the chain had skipped. That said, as I am hand cranking the engine clockwise (with plugs removed), it seems to bind up after one full revolution. Same happens in the counter clockwise direction. I am able to get it turned over so the hole in the vibration damper lines up with the lock flange, but at that point the cam marks are not lined up (granted I suppose because of vanos that isn't necessarily a given). A couple questions:


1. Is the S62 an interference engine? I've seen conflicting posts on this, but since the car started and ran (other than the chain slap) I don't think I had a valve to piston crash.

Yes it is.


2. I'm assuming w/o the plugs in place, it should be pretty easy to turn over so the binding has to be something internally (and no I didn't drop anything into the engine). I can crank one full revolution before it binds up so I'm thinking that some more of the broken chain guide is stuck on the chain itself somewhere and that's causing the binding. I'm assuming not to try and force it to keep turning.

You should feel some resistance when cranking the engine over as the valve springs compress. But it should not feel like the crank is locked when you approach this resistance. If it feels 'locked' then something is restricting the rotating assembly from moving i.e chain is getting stuck on something, or valve is touching piston. You should be able to turn the crank quite easily with a 1/4 inch ratched, short extension and 32mm socket on the vibration dampener.


3. If I line up the hole in the vibration damper with the locking flange, should the 4 cam marks line up, or is that only on every 4th revolution? Or do I need to put the TDC pin in place and then move the cams to get the marks lined up before locking?

Vanos needs to be in the initial position. Turn the crank to cyl 1 firing TDC (all 4 valves for the cylinder are closed, cam lobes for that cylinder point at each other at a ~45 degree angle). Lock the crank, then fully retard all cams and your timing marks on the cams should line up, and if timing is perfect you can drop pins in the camshafts locking holes. Initial position of the vanos means that the vanos drive pistons are not quite flush with the bore, remove the cover you will see a lip.


4. Since I can't seem to get the lock pin to line up at the same time as the cams, how should I proceed to take the vanos units off to get the chain covers off and see what the hell is going on inside the chain? In other words, if god forbid it did skip, can I proceed to take the vanos units off without locking the cams? How difficult would it be to retime the engine and set the cams correctly if I didn't lock them?

Study this DIY guide. It helped many others and myself tackle vanos unit removal and refurb :

http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/201209-diy-vanos-spring-plate-renewal.html


At this point I haven't ordered any parts, I'm still in tear down mode to see what's going one. The good news so far is I didn't see any metal or plastic on the visible parts of the chain or cams. The cam lobes show some wear but no major burning or obvious damage. The plugs and piston tops had a decent amount of carbon build up and I just started getting a AA fault before all this went down. As always any thoughts or help is appreciated.

See above.
 
#3 ·
OK will give it a shot

Thanks for the help. Definitely feels like it is locked onto something. I'm thinking not a valve because it ran before I started taking it apart. Didn't run great, but I would think if the pistons were hitting the valves it would have stopped running altogether or there would be some other damage to the cams. Ugh, I'm stopping for the night however. Been working on it for 5 hours and getting depressed.
 
#4 ·
Thanks for the help. Definitely feels like it is locked onto something. I'm thinking not a valve because it ran before I started taking it apart. Didn't run great, but I would think if the pistons were hitting the valves it would have stopped running altogether or there would be some other damage to the cams. Ugh, I'm stopping for the night however. Been working on it for 5 hours and getting depressed.
With bent valves it might still run, but with very little compression. I doubt that is your problem though. I recall having to use quite a bit of force to turn the crank once the valves were compressing.

have you removed the vanos solenoids? That makes it even easier to turn the crank with the spark plugs removed.
 
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