Rebuilt N63 - Vanos, Crank-Cam Issues!!!

[DrVirz]

Hi all,

I have recently rebuilt my N63(B4400) from ground up as I purchased it with 2 spun bearings.

Long story short, once assembled it was misfiring and getting vanos codes as well as crank-cam reference codes across all cams.

I pulled the valve covers off to check the timing, one cam was briefly out of timing. Whilst there, I removed cam gears, opened them and gave them a clean. There was some scoring in one intake and one exhaust cam gear, nothing too serious though howver a slight bit of friction. I also removed the vanos solenoids and gave them a thorough clean (should have done this prior to assembly, oops!), they were very dirty and a couple were stiff/stuck. After a thorough clean they all sound like they are working propertly when switching with 12v. Important to note that when I removed the vanos solenoids, one of the vanos oil passageways in the block had a dirt/muddy type substance in it, I cleaned it as best as I could.

I assembled the motor again and it started fine and for the first time since rebuild, it ran perfectly without misfire. I ran it for about 3 minutes then shut it off to tidy some stuff up in the engine bay.

Start the motor again, and a minor (much less than before) misfire, hmm. Ista throwing code 2A82. Shut the motor off.

Start the motor again, misfire is worse now. Ista now throwing codes 2A82 intake Vanos, 2A98 Crankshaft - intake camshaft reference, 2A9C crankshaft - intake camshaft 2 reference, all intake related...

Fiddle around a bit more, boroscope cylinders just to make sure no valve to piston contact which there is none. Compression check all checks out. So, I start the car again. Now the misfire is even worse, back to square 1 essentially. I am also getting codes for crankshaft - exhaust camshaft reference as well as 2A7f Intake variable camshaft timing control 2 and 2E1B ignition, cylinder 4.

I am a bit stumped at this stage. I will pull valve covers again to check the timing. At this stage I am thinking;

1. Could this be due to a stretched timing chain? Is it safe to run ISTA timing chain ABL even though I am getting crank-cam codes? (EDIT: see attached photo of timing chain, not sure if you can visually tell if a chain is stretched via teeth position? Chain tensioner piston protrudes about 8mm from tensioner, is this any sort of gauge of chain length/stretch?)
2. Could VANOS passageways have debris in them, and if so, any suggestions to clean them (compressed air?)?
3. Could Vanos solenoids be bad, even though I thoroughly cleaned them and they all actuated fine (from what I could tell). I.e they were nice and loud, smooth and could physically feel the piston move when supplying 12v with solenoid in hand.
4. Could cam gears be getting stuck due to internal friction/scoring, doubt it?

Any help is appreciated, thank you!

[E70x5mlemon]

Originally Posted by DrVirz

Hi all,

I have recently rebuilt my N63(B4400) from ground up as I purchased it with 2 spun bearings.

Long story short, once assembled it was misfiring and getting vanos codes as well as crank-cam reference codes across all cams.

I pulled the valve covers off to check the timing, one cam was briefly out of timing. Whilst there, I removed cam gears, opened them and gave them a clean. There was some scoring in one intake and one exhaust cam gear, nothing too serious though howver a slight bit of friction. I also removed the vanos solenoids and gave them a thorough clean (should have done this prior to assembly, oops!), they were very dirty and a couple were stiff/stuck. After a thorough clean they all sound like they are working propertly when switching with 12v. Important to note that when I removed the vanos solenoids, one of the vanos oil passageways in the block had a dirt/muddy type substance in it, I cleaned it as best as I could.

I assembled the motor again and it started fine and for the first time since rebuild, it ran perfectly without misfire. I ran it for about 3 minutes then shut it off to tidy some stuff up in the engine bay.

Start the motor again, and a minor (much less than before) misfire, hmm. Ista throwing code 2A82. Shut the motor off.

Start the motor again, misfire is worse now. Ista now throwing codes 2A82 intake Vanos, 2A98 Crankshaft - intake camshaft reference, 2A9C crankshaft - intake camshaft 2 reference, all intake related...

Fiddle around a bit more, boroscope cylinders just to make sure no valve to piston contact which there is none. Compression check all checks out. So, I start the car again. Now the misfire is even worse, back to square 1 essentially. I am also getting codes for crankshaft - exhaust camshaft reference as well as 2A7f Intake variable camshaft timing control 2 and 2E1B ignition, cylinder 4.

I am a bit stumped at this stage. I will pull valve covers again to check the timing. At this stage I am thinking;

1. Could this be due to a stretched timing chain? Is it safe to run ISTA timing chain ABL even though I am getting crank-cam codes? (EDIT: see attached photo of timing chain, not sure if you can visually tell if a chain is stretched via teeth position? Chain tensioner piston protrudes about 8mm from tensioner, is this any sort of gauge of chain length/stretch?)
2. Could VANOS passageways have debris in them, and if so, any suggestions to clean them (compressed air?)?
3. Could Vanos solenoids be bad, even though I thoroughly cleaned them and they all actuated fine (from what I could tell). I.e they were nice and loud, smooth and could physically feel the piston move when supplying 12v with solenoid in hand.
4. Could cam gears be getting stuck due to internal friction/scoring, doubt it?

Any help is appreciated, thank you!

Did you ever find the solution to this?