Setting S80 VVT

[boosted5cyl]

That sucks. I think my second seal was from the dealer. Only other things I can think of are wear on the cam, causing a leak, or perhaps excess spooge from the cam cover causing the seal to not sit squarely.

[mlanctot]

OK, I must travel tomorrow. Tuesday we'll get a dealer seal and do it one more time. Stay tuned.

[mlanctot]

I think I found the culprit. Two of the top head bolts were loose. Sealed and tightened them, lets see if this works.

[mlanctot]

I have my wife's car 2001 V70XC at this juncture to set after a head job. Same basic procedure?

[Dirtbag]

All this process and procedure seems to be for those who have removed the cams and/or the cam gears as well.
Do all these operations have to be done any time the belt is removed? The cams in question are on a 2000 Turbo S80. I watched the exhaust hub and sprocket turn CCW one and a half teeth when I slipped the belt off. Nothing else moved, so the timing hasn't really drifted. If this was caused by a spring in the assembly, and the cam moves within a degree range in that hub, then pulling the sprocket back to the correct position against the spring should (in theory) allow the original timing to be restored, without loosening several bolts and moving the slotted holes in the hub. If it was caused by a cam lobe slipping backwards off a valve, then the same process/result should occur. What tensions that spring anyhow? Cam rotation?
JimBee recommended the "crank it back into position" method, and I'm inclined to follow his lead. His experience was on an 850, but there seems to be a good deal of similarity here. Why did Volvo choose to make these engines so darned complicated?

[jimmy57]

rotate your exhaust cam CW that 1 1/2 teeth amount to let the cam be in correct place without you fighting the spring. The procedure in Vadis/VIDA is to turn the engine past the timing marks and then back it up to line the marks up with the notches on top belt cover. That relaxes spring.

When the engine runs oil pressure applied to the chambers in front and behind the piston keep the cam where the ECM wants it. When the engine is off the oil backflows through solenoid and drains and there is nothing to hold the position. The spring was there to minimize noise from the cvvt on engine start but they figured out that it was unneeded and the springs were dropped for 2002 and later models.

[Dirtbag454]

OK jimmy57, this sounds like "six of one, half a dozen of the other". If I rotate the entire cam shaft to line up the timing mark, or if I fashion a lever as JimBee suggested and pull the sprocket back to the correct position against the spring, the exact same result will happen. The cams will be correctly timed, as the CVT system will move everything into the correct position as soon as oil pressure is present. No? (please say "yes!")
It sounds like I have been over-thinking this thing. There are 46 teeth on that sprocket. 1.5 CCW rotation results in, at best, a 11.73°retard. The sprocket can be rotated back to the correct position (just did it) and it springs back when released. Should have tested that approach before, but I didn't want to do something that would lead to camshaft holders and loosening bolts to rotate timing gears to the correct position with a 6" extension stuffed in a hole behind the starter motor. (really, could Volvo have made that ANY more complicated if they tried?)
Anyhow, THANK YOU to all who have responded with this wealth of helpful information. I can move forward with the confidence that I can still send up a flare if I bollocks it up in the process. I will post the results, happy or otherwise.
Dave

[jimmy57]

Yes.

[Dirtbag454]

jimmy57, hahahahaha!

[Dirtbag454]

Ya know, if it wasn't dark out, I'd go thread that timing belt on right now. WTH, there's so little clearance that I do a lot of stuff by braille since I can't see around my hands to actually see what I'm doing. Might as well be working in the dark. Maybe it would be best to wait until I can see the timing marks to verify that all is well. Mañana.