S54 Vanos post Beisan/DV Rebuild Timing Issue

[Arinb12]

Passed vanos test and all working now!
This linked thread will explain why.
https://nam3forum.com/forums/forum/m...os-adaptations
thank you to everyone in this thread and in PM who helped me with timing and thoughts about problems!

[OldRanger]

I've just performed the Beisan VANOS procedures except for anti-rattle. I did the following: 1) replaced the oil pump disk 2) replaced the upper chain guide with OEM 3) replaced the internal vanos seals and 4) replaced the VANOS hub bolts. I had already completed the solenoid replacement to address a code last year. My engine has almost 167K miles. During the disassembly process I found that the pump disk was original and significantly battered, the OE exhaust tabs were still intact, the OE upper chain guide rail was broken, but the hub bolts were intact and torqued.

• During disassembly, I followed the Beisan procedures and in addition to that I marked the components so I could reassemble the same way I found it.
  • It went as documented, except when I attempted to "Fully retard exhaust camshaft timing", this did NOT occur: "splined shaft can be seen protruding from sprocket hub front when camshaft is at adjustment end position" I took time to try and achieve this, but was unable to, so I proceeded. The
• During assembly, I encountered some of the same imperfections as mentioned in this thread.
  • I assembled it the same way it was when I started for those things that I can be sure of.
• While checking timing with a BMW timing tool, here is what I find
  • sometimes the timing is spot on after a full engine rotation to get the cylinder 1 cams back in position.
  • sometimes I have to rotate the crank forward a couple mm from the mark, but sometimes I have to test cam timing before the crankshaft is at TDC per other suggestions.

So, I've read all of this a couple times. I've also read the BMW documentation.

I've come to the conclusion we are simply OCD and this minor variance doesnt really matter.

Why?

Per that document "The DME knows the position of the crankshaft from the signals provided by the crankshaft sensor. From the information provided by the camshaft sensors, the relative positions of the camshafts to the crankshaft are identifiable. On that basis, therefore, the DME is able modulate the relative positions of the camshafts to the crankshaft by controlling the relevant solenoid valves. The DME has stored data maps for the positions of the camshafts relative to the crankshaft. Those data maps essentially take account of the following parameters: Engine Speed, Throttle valve position, Coolant Temp.

Some of this minor variance must be due to slack in the chain without oil pressure on the tensioner. Some of this could also be attributable to the fact there is no oil pressure in the VANOS cylinders.

[sapote]

1. replaced the VANOS hub bolts.

2. Some of this minor variance must be due to slack in the chain without oil pressure on the tensioner. Some of this could also be attributable to the fact there is no oil pressure in the VANOS cylinders.

Why the hub bolts need to be replaced? Or do you mean the cam sleeves bolts which should be Loctite.

2. If the crank is turned slowly CW then the timing doesn't depend on the tensioner or slack in the chain, nor the oil pressure in the vanos because the vanos pistons are touching the vanos caps at their max forward position.

[OldRanger]

Why the hub bolts need to be replaced? Or do you mean the cam sleeves bolts which should be Loctite.

1. sapote thanks for the correction - I changed the sprocket sleeve bolts (the torx ones that need loctite)

2. In retrospect, turning the crank slowly is one of things I could have done better, and I was a bit careless the first few times I checked timing. While the Beisan instructions imply this, it didn’t sink in for me that the precision of your timing check can be affected.

In the instructions from Beisan website that precede the hub bolt tightening sequence - this statement is included: “Turning crankshaft counter clockwise is acceptable.“

I disagree with that after watching how it affected the relative position of the TDC mark in comparison to the cams.

More retrospective:
1) follow only one set of instructions - The Beisan ones are good, but mind numbing (likely a reflection of TIS)
2) be very disciplined with the hub bolt tightening sequence, and understand this accomplishes more than simple alignment of the bolts - it is properly compressing the diaphragm spring as well.

Its not so much an obsessive concern about timing…but I will remove and reinstall my VANOS today to rework the hub tightening process and get that right.

[OldRanger]

Linking related topics as there are numerous to review. Sometimes the internal search feature doesn't produce results as well as Google. I think this is a reasonable repository of VANOS threads/topics. I'm trying to think of a way to simplify organizing all of this, but this is the best I can do at this point. Maybe a moderator can assist? sapote

1: Having trouble timing after VANOS work? Wondering why your timing is good one rotation and not the next? Wondering if it's really OK to turn the crank CCW? You are not alone, and the posts on this board are extensive. There is a lot to consider, but I'll add: remember some of these engines are high mileage and wear on these timing chain components is inevitable and relevant.

8/16/20, OP is avusblue Timing s54 after vanos rebuild installation, 4 pages https://nam3forum.com/forums/forum/m...d-installation
3/7/21, OP is Joshb556 S54 Vanos post Beisan/DV Rebuild Timing Issue, 6 pages https://nam3forum.com/forums/forum/m...d-timing-issue
1/27/23, OP is nextelbuddy Vanos Timing Question, 2 pages https://nam3forum.com/forums/forum/m...iming-question
1/17/21, OP is Cubieman Engine Wont Time Post VANOS Install, 4 pages https://nam3forum.com/forums/forum/m...-vanos-install

2: Want an alternative method to torque the VANOS Hub Bolts to Spec? It is a generally accepted fact that improperly torqueing the hub bolts could throw off timing.
1/11/21 OP is sapote Why use a method that you can't torque the VANOS hub bolts to spec?, 2 pages https://nam3forum.com/forums/forum/m...-bolts-to-spec

3. Need advice for VANOS testing and/or adaptations:

6/13/20, OP is boadly Need help doing vanos test with INPA, 6 pages https://nam3forum.com/forums/forum/s...test-with-inpa
1/28/22, OP is Arinb12 What are vanos adaptations?,1 page, https://nam3forum.com/forums/forum/m...os-adaptations

4: Difficulty starting after VANOS work - this thread is lengthy and delves into root cause analysis

2/25/23 OP is jamesfoley Vanos Rebuild Start Hesitation, 12 pageshttps://nam3forum.com/forums/forum/main-forum/e46-2001-2006/207251-vanos-rebuild-start-hesitation

[Slideways]

1. sapote thanks for the correction - I changed the sprocket sleeve bolts (the torx ones that need loctite)

2. In retrospect, turning the crank slowly is one of things I could have done better, and I was a bit careless the first few times I checked timing. While the Beisan instructions imply this, it didn’t sink in for me that the precision of your timing check can be affected.

In the instructions from Beisan website that precede the hub bolt tightening sequence - this statement is included: “Turning crankshaft counter clockwise is acceptable.“

I disagree with that after watching how it affected the relative position of the TDC mark in comparison to the cams.

More retrospective:
1) follow only one set of instructions - The Beisan ones are good, but mind numbing (likely a reflection of TIS)
2) be very disciplined with the hub bolt tightening sequence, and understand this accomplishes more than simple alignment of the bolts - it is properly compressing the diaphragm spring as well.

Its not so much an obsessive concern about timing…but I will remove and reinstall my VANOS today to rework the hub tightening process and get that right.

Why are you removing the VANOS again? It sounds like you did it correctly in your previous post. It is most likely slack in the chain causing the timing to go out a hair after turning the crank back to TDC. To satisfy the OCD, all it takes is nudging the cam with the 24mm wrench to get the pins to slide through perfectly as they did with the VANOS off. We are probably talking about less than a degree as that BMW timing tool is very precise. Even if you turn the engine over again to TDC a third time, the cam pins still might not slide in perfectly smooth. The timing should be fine as long as the VANOS splined gears were fully pushed into the VANOS unit before install.

Two things that should be revised in the Beisan DIY are the counterclockwise thing and the TIS (and Torque PDF) has the torque setting for the chain guide bolt at 13Nm (Beisan has it at 24Nm!). Beisan also has the strut brace nuts torqued to 40Nm when it should be 24Nm according to the Torque PDF.

[sapote]

1. In retrospect, turning the crank slowly is one of things I could have done better, and I was a bit careless the first few times I checked timing. While the Beisan instructions imply this, it didn’t sink in for me that the precision of your timing check can be affected.

2. In the instructions from Beisan website that precede the hub bolt tightening sequence - this statement is included: “Turning crankshaft counter clockwise is acceptable.“
I disagree with that after watching how it affected the relative position of the TDC mark in comparison to the cams.

1. Turn CW fast if you want, but slow down when about 1" to TDC.

2. Read through this and see it is better for you:

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/78519-why-use-a-method-that-you-can-t-torque-the-vanos-hub-bolts-to-spec

[OldRanger]

Why are you removing the VANOS again? It sounds like you did it correctly in your previous post. It is most likely slack in the chain causing the timing to go out a hair after turning the crank back to TDC. To satisfy the OCD, all it takes is nudging the cam with the 24mm wrench to get the pins to slide through perfectly as they did with the VANOS off. We are probably talking about less than a degree as that BMW timing tool is very precise. Even if you turn the engine over again to TDC a third time, the cam pins still might not slide in perfectly smooth.

I decided not to take the VANOS off. But I did rework the timing procedure a second time in order to ensure I had properly torqued the hub bolts. When complete, I checked timing and still the cams were slightly off - a little behind the crankshaft from perfect. Maybe 1-2 degrees. I watched closely what the sprockets, timing chain, and splined shafts were 'doing' when I fiddled (rotated) the camshaft with the 24mm wrench. I considered the explanations from contributors on this forum. I decided I was good to go and ready for a test drive.

• I completed reassembly.
• I did not reset VANOS Adaptations.
• I did not test VANOS.
• I cranked the car and let it idle. The only odd sound I heard occurred within seconds and was a singular high pitched clunk...presumably part of the process of purging air out of the VANOS.
• I warmed the car to temp and took a 5 mile drive.
• No codes.
• Car has improved 'return to idle'. Seems like it might pull a bit stronger in high revs.

Conclusion: these minor issues we see timing our 20 year old engines is all due to ever so slightly worn camshaft sprockets and chain. Others have written this, and I concur. In retrospect:

Performing a timing procedure that is intended for an engine withOUT any appreciable wear...on an engine with almost 170K miles...and expecting the results appropriate for a low mileage engine is a silly notion.

Thanks for sharing your ideas everyone!