Engine won't time post Vanos install

[Cubieman]

I have installed my Vanos and tightened the hub bolts 5 times now and each time it's the same outcome. Both cams end up being slightly out of time in that I must very slightly turn the crank CW past TDC for the bridge pins to fall into place.
I have been following the beisan instructions using Lang hub bolts. Last night after pretensioning the hub bolts and tightening the top most hub bolts I removed the vanos (leaving the splines in the hubs) and was able to use a torque wrench to properly get each hub bolt to 10.5 ft lb and then put the vanos back on. This yielded the same result, once the engine was turned over both cams were out of time (needed to be Advanced).


After I pretension the hub bolts with the Vanos 5mm from the head I check timing (OK)

After I evenly tighten/torque (7ft lb) the Vanos to the head I check timing (OK)

After I tighten the top most hub bolts I check timing (OK)

I turn the engine over to tighten the remaining 3 hub bolts and then turn it over again back to TDC (lobes pointing to each other) and I check timing (NOT OK)

I have tried the Beisan procedure for adjusting timing but every time I have to turn the engine over after tightening the first set of hub bolts I loose my timing.

As many of you know I turned the crank while the timing tool bridge and pin were still installed. This caused the pin to break and it fell into the oil pan.
I wonder if this could have stretched my timing chain so now the engine will not time. Also when I re-installed the timing chain tensioner there wasn't much oil left in it as I dumped some out of it.

I don't know how much play there should be in the chain when the vanos is installed and all the hub bolts are tight but I can moved my chain up/down a little bit, its not absolutely tight.

Sorry to beat this to death but its just not seeming to want to time properly and I feel like I am running out of things to try to produce any kind of different result.

[sapote]

You had a little chain slack on the pulling side for some reason, leading to little cam timing retard after turning the crank. Everything else you did perfect.

No big deal, here you need to do: repeat from start but have the cams timed with bridge pin, but have the bridge slightly up on the intake side, maybe 1mm up.
This will take the problem you have.

Edited: I meat to say little high on the exhaust side

[sapote]

Your issue is having chain slack on pulling side (right side vu from front)

Never turn crank Ccw when set it to TDC. Turn CCW causes the problem.

[Icecream]

How high is the bridge when it's not flush? The TIS mentioned a small amount was acceptable (1mm is probably fine as sapote said) Mine was like that the first time I did it, no issues and passed vanos testing. I think you can cheat it a little before tightening down and then it sits flush.

[Cubieman]

It's just over 1mm sitting up off the intake side when pin is inserted into the exhaust cam. On the intake side the bridge will sit more or less flush if I lift up on the bridge while I put the pin in, but even then the pin is difficult to insert.

When I first set the cams up the pin drops easily into each cam requiring little to no pressure to seat it into the bridge. But after I tighten the top hub bolts and turn the crank that perfect setup is lost.

I just wonder if I didn't ruin (stretch) my timing chain when I turned the crank with the bridge/pin installed. Although the same timing issue happened before that incident.

[Cubieman]

You had a little chain slack on the pulling side for some reason, leading to little cam timing retard after turning the crank. Everything else you did perfect.

No big deal, here you need to do: repeat from start but have the cams timed with bridge pin, but have the bridge slightly up on the intake side, maybe 1mm up.
This will take the problem you have.

So you mean when I set the cams timing I will have approximately 1mm between the head and the bridge on the intake side? I just wonder why there is so much slack.

[thundermoose]

What you’re seeing is fine. The vanos has quite a bit of range to play with timing. If you turn your engine over by hand multiple times with vanos solenoid body unattached and then manually set the cams to full retard, the bridge pins should easily slide in


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[Cubieman]

What you’re seeing is fine. The vanos has quite a bit of range to play with timing. If you turn your engine over by hand multiple times with vanos solenoid body unattached and then manually set the cams to full retard, the bridge pins should easily slide in


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Thats my issue, the bridge pins don't easily slide in after turning the engine over and retarding the cams.

[thundermoose]

Thats my issue, the bridge pins don't easily slide in after turning the engine over and retarding the cams.

I can tell you from experience that the car will pass vanos test with a lot less effort and precision than you’ve put in.


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[Cubieman]

I can tell you from experience that the car will pass vanos test with a lot less effort and precision than you’ve put in.


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To have the bridge pins slide in I must remove the crank locking pin and move the crank just a bit CW. Not much, just past the point of the crank locking pin being able to be inserted.
As Sapote was saying, its likely slack in the chain and I will basically have to "mis-time" my cams to account for that and when I turn the engine over and put the crank locking pin in place then hopefully the bridge/pins for the cams will slide into place as they should.
It's just bothersome that I can't set it up and have it hold it's timing as it should due to chain slack.

[sapote]

My bad; higher 1mm on EX side for advanced , not on IN side.

[Icecream]

To have the bridge pins slide in I must remove the crank locking pin and move the crank just a bit CW. Not much, just past the point of the crank locking pin being able to be inserted.
As Sapote was saying, its likely slack in the chain and I will basically have to "mis-time" my cams to account for that and when I turn the engine over and put the crank locking pin in place then hopefully the bridge/pins for the cams will slide into place as they should.
It's just bothersome that I can't set it up and have it hold it's timing as it should due to chain slack.

So just to clarify, when you initially time it, bridge is flat with pins inserted.
Then, when you tighten things down and turn the engine over, then check timing again then the bridge won't sit flat and there is a 1mm gap opposite of the cam with the pin in it?

[Cubieman]

My bad; higher 1mm on EX side for advanced , not on IN side.

Ok, I think what I will do is try this with the vanos installed just to give me and idea of how much the cams need to be "mis-timed" to end up in time after the crank is turned.
I'll turn the crank from TDC lobes 45° to TDC again and loosen the bottom hub 3 bolts, then turn it back to TDC lobes 45° and loosen the top 3 hub bolts. The cams will then be free to turn.
After I've figured out where the cams need to be I may remove the vanos again and start over with that information.

[Cubieman]

So just to clarify, when you initially time it, bridge is flat with pins inserted.
Then, when you tighten things down and turn the engine over, then check timing again then the bridge won't sit flat and there is a 1mm gap opposite of the cam with the pin in it?

Exactly, 1mm (approx.) gap on the intake side when checking the exhaust cam and the intake is less than that but still off. If I turn the crank just slightly CW the bridge sits flats, but of course then the crank pin won't go in so it's not at TDC.

[thundermoose]

Exactly, 1mm (approx.) gap on the intake side when checking the exhaust cam and the intake is less than that but still off. If I turn the crank just slightly CW the bridge sits flats, but of course then the crank pin won't go in so it's not at TDC.

Assuming you've done everything correct to this point...

After I pretension the hub bolts with the Vanos 5mm from the head I check timing (OK)

After I evenly tighten/torque (7ft lb) the Vanos to the head I check timing (OK)

After I tighten the top most hub bolts I check timing (OK)

...The cams are in time.

If you want, you can remove the vanos end caps and note the position of the pistons when the crank is at TDC and the pins slide in easily. Remove the bridge and the crank lock and turn the engine over 20 times. Then put the crank back a TDC. Take your 24 mm wrench and retard the cams so that the pistons are in the exact same position that you started with. The pins should slide right in, but EVEN then if they are only slightly off, it won't matter because the computer is going to deal with any minor offset you end up with. That’s the beauty of variable timing and camshaft sensors.

If you really want feedback, video all your steps and post it to youtube and then include a link. To me, it sounds like you are doing everything right.

When I do vanos, I turn the engine over a couple of times to make sure I didn't make a big mistake but I don't bother to check with the bridge because the pistons will move slightly and there is a bit of hysteresis in the chain. I run the Vanos test on DIS/GT1 and it always passes and is typically dead nuts on with offsets.


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