P0021 After Timing Chain Guides + Vanos Rebuild

[dannyzabolotny]

I did a whole bunch of Googling and I searched this forum before posting, but at this point I'm out of ideas. My engine runs perfectly. It idles smoothly, accelerates smoothly, and never has any other codes. I've driven it with this P0021 for a month or two now because there was no real harm to it, but I want to fix it now.

I messaged JimLev about it some time ago, and he suggested removing the driver's side valve cover and adjusting the camshaft timing wheel, which I have done twice at this point. I'm a bit of sick of removing my valve cover and reinstalling it, having done that for two days in a row. Neither adjustment helped to fix the code. I've tried clearing the codes, which makes the SEL go away, but then as soon as I restart the engine the SEL light comes right back on. Once the SEL is cleared, it never comes back until the next startup, where it comes back about 5 seconds into the engine running.

When I originally timed the engine, I used all of the proper timing tools, JimLev's cam block holding tools, and numerous tutorials for the actual timing process. The cam blocks never moved during timing, and the camshaft trigger wheel alignment tools fit perfectly after I cranked the engine over by hand a few times. Both Vanos units were fully retarded, and the timing chain tensioner tool was set up correctly as well.

What could my problem be at this point? Bad camshaft timing sensor? I had no codes at all prior to the rebuild so it would be odd if the sensor just stopped working all of a sudden. Both upper timing covers were installed the proper way, using the Beisan Systems valve cover pressing method.

At this point I'm just tempted to put electrical tape over the SEL and let it be, but that's just ghetto and improper.

[JimLev]

Danny, got your PM, just been real busy.
Pin the crank at TDC, pull the valve cover off, take the torx screw out of the upper timing cover, put the cam blocks on the cams (retard the intake cam if you have to), then get a drill bit that just fits thru the torx screw hole and make sure it aligns with the hole in the trigger wheel. If it doesn't loosen the 24mm nut and adjust the wheel.

[gmak]

Did you see the posts regarding re-loosening the Cam sprocket bolts after tightening them. Apparently, it's in the TIS. If not, the posts are here, including some tips regarding the dread P0011 and P0021 codes. If you did, man that is one nasty code.

[vinyldude]

If you have INPA (or some other BMW diagnostic tool )available, it gives some additional information besides the error code that can be hopefully used to diagnose the issue further.

My problem was that vanos units didn't stay fully retarded when things got buttoned down. You obviously had better tools available (the cam block holders) so I don't know.

[dannyzabolotny]

Danny, got your PM, just been real busy.
Pin the crank at TDC, pull the valve cover off, take the torx screw out of the upper timing cover, put the cam blocks on the cams (retard the intake cam if you have to), then get a drill bit that just fits thru the torx screw hole and make sure it aligns with the hole in the trigger wheel. If it doesn't loosen the 24mm nut and adjust the wheel.

Sounds like an idea, but all of my timing tools are in NJ, I rented them to somebody. So now I have to either wait for them to come back or figure out how to do this without them.

- - - Updated - - -

Did you see the posts regarding re-loosening the Cam sprocket bolts after tightening them. Apparently, it's in the TIS. If not, the posts are here, including some tips regarding the dread P0011 and P0021 codes. If you did, man that is one nasty code.

I read that post just now, but I don't think it's that. I had the bolts in pretty loosely when I started the timing process. I didn't tighten them at all until I actually got to locking the timing.

[capebmw]

Follow Jim direction and use the screw in the timing cover method. Or since it is running fine, wait until your tools come back.

[vinyldude]

It is probably the best to wait for your timing tools to get back, if you want to get to the bottom of it.
With these vanos code issues I tend to think the most likely root cause is how the cams were tightened down, rather than how the trigger wheels were set. If the timing covers are level with the heads (which is pretty easy to observe) it seems very unlikely to me that the trigger wheel tools and the way those are used would cause any errors.

With the engine at TDC and the chain fully tightened, while holding the intake cam fully retarded with an open wrench, the cam timing blocks should easily slip up and down (and be level with the heads when down) when you try to lift them with your other hand. If you can't move the timing blocks without some kind of an additional force being exerted either to the timing blocks or the vanos cam position, there is some slight error in cam timing.
If you see any error here for either of the banks (no need to remove upper timing covers for this test), you need to re-time the cams and after that also do the trigger wheels again.

I know you've done the whole thing too many times already, but just going through it one more time with this thought in mind that the timing blocks need to be able to move for the timing to be dead accurate might help.

Just tweaking the trigger wheel positions may get rid of the codes, but may hide the underlying error in cam timing.
Good luck!

[purplecty]

My buddy is having the same issue after doing guides on a 4.6is. He has done dozens of other M62tu engines, so he knows what he is doing. Was this ever resolved danny?

[Kenny1958]

Danny, got your PM, just been real busy.
Pin the crank at TDC, pull the valve cover off, take the torx screw out of the upper timing cover, put the cam blocks on the cams (retard the intake cam if you have to), then get a drill bit that just fits thru the torx screw hole and make sure it aligns with the hole in the trigger wheel. If it doesn't loosen the 24mm nut and adjust the wheel.

So it seems that after i've done my vanos units i find myself with a code 34 camshaft control bank 2 situation.

Should i adopt the same stance Jim with the drill bit ?

Luckily bank two is quite a bit easier to access than bank 1

[dannyzabolotny]

The trick with adjusting the cam timing wheel has worked for me multiple times since I posted this, so yeah it's a proven solution. Ideally you want to lock the flywheel at TDC and install the cam lock blocks, as that'll give you the best idea of where the wheel needs to move. Otherwise you're kinda turning the little wheel blindly and it takes several tries to get it right— I've done it both ways, and doing it the proper way using the timing tools saves a lot of time and effort.

[Kenny1958]

I have all the timing tools at hand, can i get away with locking the crank and having the blocks on bank 2 only then reposition the timing wheel ?

[JimLev]

Kenny, yes pin the crank and lock down the cams.
You may want to loosen the center vanos nut and make sure the vanos is fully retarded.

[Kenny1958]

Kenny, yes pin the crank and lock down the cams.
You may want to loosen the center vanos nut and make sure the vanos is fully retarded.

Thanks i'll get on that when i can, i've got an infection at the moment and feel pretty crap. Its not given any sel lights i just found out by checking the codes. ?

[Kenny1958]

Ok today i had a hospital appointment which really didn't take long at all and seeing as i had booked a day off work i thought i would have a look at this.
I removed the cam covers and loosened the upper chain case cover on bank 2 and using a selection of washers managed to press down the upper chain case cover so that it seated flush. I then undid the torx screw and popped a drill through the hole and it went smack bang through the hole in the shutter wheel so it seems to be good.
I started up inpa and checked and cleared the 34 code and fired up the motor i checked the codes again and saw there was none so could it be that i'm in a good place now with this timing ?? i don't suppose i'll know for certain until i get chance to drive it and find out if any codes come back at me.

[Kenny1958]

Well i checked for codes today for the 34 code and it seems that just tightening down the bank 2 upper timing case has done the trick unfortunately i forgot to put a bit of sealer in the corner of said UTC and now i have an oil leak so i'll have to revisit it.

[E30User]

You mentioned Cam Position Sensors. Have you tried swapping the sensors with the one on the opposite side to see if the reported bank changes? After I did my rails/vanos, I couldn't get the car started. It would just crank. I redid the timing and still had the problem. At some point I changed the CPS and everything started working. My original CPS was pretty old and I think I might have broke some of the brittle wires when I was removing/reinstalling it. Maybe yours could be damaged only slightly.

[dannyzabolotny]

You mentioned Cam Position Sensors. Have you tried swapping the sensors with the one on the opposite side to see if the reported bank changes? After I did my rails/vanos, I couldn't get the car started. It would just crank. I redid the timing and still had the problem. At some point I changed the CPS and everything started working. My original CPS was pretty old and I think I might have broke some of the brittle wires when I was removing/reinstalling it. Maybe yours could be damaged only slightly.

Yeah, I always try swapping sides to rule out a bad sensor. So far I've never had an issue with the sensor itself, it was always in the timing wheel being slightly off.

[JimLev]

Unless the static timing was done wrong (hard to do if your using the correct tools) it's almost always is the trigger wheel not being set correctly assuming that the vanos was FULLY retarded.