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Checking cam timing FYI

1K views 2 replies 2 participants last post by  E39LeMansM5 
#1 ·
For anyone that is considering doing cam timing adjustments, I can't stress how critical it is to watch what I'll call the female helical piece that accepts the helical gear. Maybe it's the sprocket? You have to watch the gap between the vanos and inside the head when turning cams to a full stop you will see the helical female piece come out and into the visible gap and when at full stop it will completely close the gap. If you haven't been able to turn the cams far enough try working the cam backwards and forwards with your wrench and then pull hard to counter clockwise to try and get it to go all the way (this all has to be done with the solenoid boards removed, or with the electric switches and air adapter. I thought I had some cams that were timed correctly, but they just weren't letting me turn them to full stop for whatever reason (wrench clearance, etc.)and when I finally was able to get them to turn to full stop, the timing was off. Not by a huge amount but enough to need resetting. I'd say the inside gap straddled the outside gap line on the cover, half on the inside, half outside.

It is hard to find clearance to work your wrench in such tight quarters. An adjustable pliers wrench may be needed. Modifying the 27mm spanner would help to but I wasn't able to do that. I don't know why they put the darn cast hex piece right in line with the abs system which makes in near impossible to turn the exhaust cam all of the way, and you really risk scratching a cam lobe as you try to get a good hold on the cast in hex part of the cam. Why couldn't they have put this further back on the cam shaft?? Anyway, as I mentioned, my cams do need adjusting and I feel I have a good handle on the process, I just don't have the right tool to be able to torque the sprocket bolts currently. I'm going to try a 10mm crows foot on a torque wrench and see if that works. Don't really want to pay ECS $100 for a 10mm spanner with a piece welded on to connect a some special type of torque wrench. Not even sure what kind of torque wrench it is. It apparently should have an open square end that slides over the modified spanner. You can see it in the TIS pictures. But anyway if you want to check timing and adjust it, it doesn't look that bad just remember you aren't at full stop until you see that part of the vanos completely come out of the head and you'll see the start of the helical portion and the gap will be completely closed at the timing cover. I guess you could take the covers off the pistons to check but I didn't.

Good news is my exhaust and intake cams on bank 1 were out of time and I'm pretty certain that helical female gear piece may have been seized up, because you can audibly hear them pushing our air or oil when turning the bank 2 cams to full stop. I was really hoping that they would be out of time, meaning that power was being left on the table, so hopefully getting timing set correctly will help improve things. If you do this job plan on having a few days available. And a big bowl to place all of the hardware you will be removing.
 
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#3 ·
I have had good luck with a Craftsman 27mm wrench. It fits both cams on bank 2 without issues. On bank 1 the intake cam is easy but the exhaust cam takes a bit of maneuvering. You have to put the wrench over the round part of the cam slightly to the left of the hex and then move it over the hex and it will fit.
 
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