Need help diagnosing problem after vanos update

[boadly]

What did you torque the hub bolts to?

Edit: nevermind I just saw you responded above.

Cam hub bolts were tightened to 12 Nm and exhaust hub bolts to 14 Nm.

[boadly]

I don't agree with everything these guys do but it's a good visual aid alongside the Beisan procedures.

As the start of this video, the hub bolts are finger tight, crank is at tdc, and cams are aligned using the bridge.

https://youtu.be/_nMUCe7TD2o

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That's one of the videos I watched. I take my time and I'm pretty meticulous about following all of the instructions in this video and other sources so I don't understand what went wrong.

[boadly]

Don't know if anyone watched the video in the first link I shared from Google Photos that shows the exhaust timing constantly bouncing around between approximately 19 degrees and 8 degrees. Does that give any insight into the problem as opposed to staying more constant? I didn't know if it could actually bounce around that much that quickly or that could possibly be in error.

[sapote]

Like I said I can't move either cam more than a few millimeters with the hub bolts tightened even with the solenoid off. So with the crank locked at top dead center and the hub bolts loosened I would rotate the cams so they would perfectly align with my BMW timing tool. I then tightened the hub bolts and reinstalled the Vanos making sure the camshafts didn't move. After that, I rotated the crank multiple turns, locked the crank and checked the timing again. At that point I may have had to rotate the cams a millimeter or two to get the pins on the timing tool to slide in perfectly.

you did it all wrong based on what you wrote in bolded words.

Yes, when I opened it back up you could see the timing was off.

This confirms that you did the timing wrong as in bolded above.

[sapote]

"So with the crank locked at top dead center and the hub bolts loosened I would rotate the cams so they would perfectly align with my BMW timing tool. I then tightened the hub bolts and reinstalled the Vanos"

It's wrong to bolt up the hub before install the VANOS. Read up the instruction and ask question if needed.

[boadly]

"So with the crank locked at top dead center and the hub bolts loosened I would rotate the cams so they would perfectly align with my BMW timing tool. I then tightened the hub bolts and reinstalled the Vanos"

It's wrong to bolt up the hub before install the VANOS. Read up the instruction and ask question if needed.

Thanks, I wrote that wrong. I tightened two of the bolts opposite of each other on both sides, backed them off 1/4 turn then installed the vanos and then tightened down all of the exhaust hub bolts.

[sapote]

It's impossible to have the EX cam too advanced at idle if everything was bolted down and the cams were verified with the timing bridge tool with crank at TDC. However, It's possible for ex to be error with too much retarded. Are you sure EX is too advanced and not retarded?

[boadly]

It's impossible to have the EX cam too advanced at idle if everything was bolted down and the cams were verified with the timing bridge tool with crank at TDC. However, It's possible for ex to be error with too much retarded. Are you sure EX is too advanced and not retarded?

I'm not sure of anything at this point, lol. You can see the numbers from the tests I posted.

[sapote]

I'm not sure of anything at this point, lol. You can see the numbers from the tests I posted.

At idle EX timing should be 0 degree which is the max advance. Therefore anything not zero is retarded timing. If you're having EX too retarded at idle then it is understandable -- mostly due to wrong timing setup. When the engine turned off, the EX should be resting at max advanced, which means you can verify this by seeing the VANOS piston at its most reward position (to push the spline shape deep into the hub). So just open the VANOS piston cap and see the piston position.

[boadly]

At idle EX timing should be 0 degree which is the max advance. Therefore anything not zero is retarded timing. If you're having EX too retarded at idle then it is understandable -- mostly due to wrong timing setup. When the engine turned off, the EX should be resting at max advanced, which means you can verify this by seeing the VANOS piston at its most reward position (to push the spline shape deep into the hub). So just open the VANOS piston cap and see the piston position.

Not sure if it's at max advanced but is close to it. That's why I can't pull the vanos back to remove the splines without loosening the hub bolts as the exhaust spline is deep in the hub and I can't rotate the cam to retard it.

[sapote]

It’s 19 crank degrees retarded instead of zero, which means if the EX cam is marked for reference after engine turned off, then open the piston cap and solenoid plate removed, try to advance the EX cam with 24mm wrench while pushing in the piston, the cam should advance 19/2=8.5 cam degrees to its max position. If this is confirmed then we know what’s wrong.

[boadly]

It’s 19 crank degrees retarded instead of zero, which means if the EX cam is marked for reference after engine turned off, then open the piston cap and solenoid plate removed, try to advance the EX cam with 24mm wrench while pushing in the piston, the cam should advance 19/2=8.5 cam degrees to its max position. If this is confirmed then we know what’s wrong.

I was finally able to get back to working on my car this weekend. I put the old exhaust hub back in and ran the car briefly at idle but still got the same codes with the exhaust cam being off by a little less than 20 degrees. Same thing as before as It would actually constantly bounce around from approximately 10 to 20 degrees.

I took everything apart again and after locking the crankshaft at TDC I was able to get the pin in the timing tool for the intake side. The exhaust side pin wouldn't go in as the cam was rotated too far clockwise.

I then tried to rotate the exhaust cam . It was extremely hard to move in either direction. The exhaust spline shaft was already deep in the hub. Rocking the cam back and forth with a significant amount of force and pushing on the spline shaft I was able to move it slightly further into the hub. I then rocked the cam back and forth to bring the spline shaft all the way back out of the hub. At that point I was able to get the pin in the timing tool.

Again it took a significant amount of force and a significant number of very small rocking motions to finally get the camshaft rotated counter-clockwise to be in time.

The first two photos are with the crank locked at TDC before rotating the exhaust cam. The remaining photos were taken after rotating the cam to be in time.

To recap, regardless of whether I put in my old vanos or old exhaust hub or new vanos and new exhaust hub I still get the same results. Every time I take it apart I get the timing perfect then rotate the crank several turns and recheck the timing. But then when I start it the exhaust cam is off significantly.

I'm pretty much at a loss at this point. The only thing I can think of is that it's electrical. I guess the way the vanos works is the camshaft sensor and crankshaft sensor have to communicate with the ECU and then the vanos so maybe one of those is not communicating correctly.

One other thing and I don't know why it would matter but I did put in new S62 spring washers (or whatever they're called) in the hubs.

Thanks again if anyone has any suggestions.

[sapote]

I will thinking about the root cause. I'm surprised that you're indeed having the EX too advanced, which is unusual as most people made error of EX with retarded.

[sapote]

I then tried to rotate the exhaust cam . It was extremely hard to move in either direction. The exhaust spline shaft was already deep in the hub. Rocking the cam back and forth with a significant amount of force and pushing on the spline shaft I was able to move it slightly further into the hub. I then rocked the cam back and forth to bring the spline shaft all the way back out of the hub. At that point I was able to get the pin in the timing tool.

Again it took a significant amount of force and a significant number of very small rocking motions to finally get the camshaft rotated counter-clockwise to be in time.

This is good news as you did not say this previously (it seemed you had to remove and install the hub again in order to retime the cam).
Q: as you rotated the cam CCW, could you rotate it pass the bridge pin position -- further than where the pin can be inserted in)? If you cannot rotate the cam CCW passed the bridge pin then it means the piston had bottomed on the cap at the pinned position, which is correct.

[sapote]

Did you work on the EX cam sensor/wire? I don't think you touch the cam sensing wheel at the rear end.