new to me, 98 M3

[cpandrewschmidt]

well damn.  Injector guy just called back after testing.  Said they're 100% fine.  Figured since they really only have about 27k miles on them.  

Looks like I'll be trying my vanos job one more time.  Really isn't anything else I can test at this point.  Gotta track down that air tool to test chain movement that I'm reading about online.  Can't find it anywhere.

[Jdesign]

Damn thats a bummer.

[cpandrewschmidt]

I'm about to tackle this vanos yet again tonight.  This time with compressed air.  I'm seeing conflicting info online on the procedure though.  

1. Do I keep the cam lock blocks on?  
2. Loosen the exhaust torx bolts a bit? 
3. Lastly, do you put tension back on the chain?  

If anyone knows for sure that'd be great!  Thanks

[B C]

Disclaimer: I am just spitballing. I don't even have a running 24v engine and cannot say for sure that I even did my own timing and VANOS correctly. I might be a complete idiot:

1. EDIT, After thinking about it some more: you dont want the cam lock blocks on

2. I would dial the pressure regulator on your air compressor down to  55-60psi since that's approximately the oil system operating pressure and you don't want to hit it with excess pressure if you don't have to. I would run the test with the exhaust torx bolts as-is just to check for movment to make sure it is actually able to move. After that, I would remove the exhaust torx bolts, remove the washer plate (green star) then replace the exhaust torx bolts loosely without the washer plate installed so you can see the slots on the sprocket and verify the full range of motion (how the bolt aligns with the slot, ensuring the vanos movement uses the full span of the slots).

3. I would run the tests with the chain tensioners all in place as if the engine is running to replicate how things are moving in reality.

in addition, I would check to see if the arrows on your primary and secondary exhaust sprockets are  both pointing to roughly 12:00/upward at TDC like the blue arrows indicate (as opposed to 3:00, 6:00, or 9:00 like the red arrow shows). I haven't measured or confirmed anything but I have a suspicion that those arrows exist because the slots are machined relative to the sprocket teeth and may not be totally symmetrical when installed 90, 180, or 270 degrees out.

[cpandrewschmidt]

Thanks Snap.  That's pretty much the same response I got on the M3 forums.  I'll let you all know how it goes.  

"Locks on
E-torx loose
Chain tension yes

The idea is to set the position (air on, solenoid off) to lock the exhaust torx down. The same thing you did when attempting by hand. You also get to see the movement range while cycling on/off several times on the solenoid before finishing with off to tighten the torx. "

[cpandrewschmidt]

Hey all,

So working on this right now tonight.  I followed the steps above (cam locks, backed off torx bolts, tension on chain). I wanted to check chain movement before uninstalling vanos just to see where it was at. Applying pressure and activating the solenoid the chain didn't budge. You can hear the vanos make a blurping noise and the cylinder with the gear moves in and out just a little bit. Appears the solenoid is fine as it clearly does something when voltage is applied to it. 

So, figured it was installed wrong, uninstalled and re-installed. Same thing. I'm very careful to make sure I'm catching the 1st possible gear. 

I'm surprised that 60 psi is going to move the chain.  It's hard enough to move the chain clockwise with the cam gear wrench.  Doesn't seem like anything will move with the CAM blocks on.

I took a video but not sure how to post a video. I'll try to figure that out. If anyone has any ideas in the meantime please let me know.

[cpandrewschmidt]

got a video on you tube.  you can see the vanos gear thing twitch with I apply voltage to it on and off

[B C]

I just realized you need to test it with the cam locks off. The cam phasing wont change with them locked together (duh)

[cpandrewschmidt]

well, didn't make a difference with cam locks off.  Same thing.  I've taken the whole thing apart again and reinstalled.  Same problem.  Took the vanos apart to check seals and inside.  Those all seem fine.  

Perhaps my rig for applying air?  Should I not have the oil feed line attach?  I have an aftermarket oil pressure guage that tees off that, so mine is a bit different.  I was able to get a hose clamp attached to that.  Air doesn't leak and does go through even with the kink.  Other end just connected to the compressor with 60 psi. I do hear air coming out from somewhere under the exhaust cam gear.  I assume oil feeds into the head somewhere in there.  But air pressure definitely escapes through there.  

[B C]

The air is going to take the path of least resistance through the oil line and you wont have much pressure at all inside the vanos unit

[cpandrewschmidt]

yeah, this is my bolt going into vanos.  I assume I need something that bypasses the oil feed line (that black line?)  I was just applying air to the end nipple part with the bolt still screwed in and oil line attached

[B C]

https://www.amazon.com/Vanos-Tool-Banjo-Fitting-113450/dp/B010O1FBLC

This plus an unmolested banjo bolt

[cpandrewschmidt]

Hi all, hope everyone is doing well.  Not a ton to report on the M3.  Got the new trunk on.  Looks much better.  Not 100% perfect unless you're very close to it and know what to look for. I like it.  Small m5 spoiler coming today. 

Back to the vanos stuff.  Did it a 3rd time, confirmed chain movement was correct with compressed air.  All seemed fine.  Drove it for a couple weeks with no CEL.  Had at least 30-40 different start and stops over the time period, so DME had plenty of time to trip early on but didn't.  Then it came on again this week.  Ugh, same thing, mixture deviation bank 1, misfire cylinder 5.

So, I did an experiment.  I changed coil pack (CP) to cylinder 2 and spark plug (SP) to cylinder 3.  Put known working CP and SP from cylinder 2 onto cylinder 5.  

Now I get misfire on cylinder 5 and 3 (where the spark plug went) but cylinder 2 is good with the CP off 5.  So, I know CP's are fine. (again all CP and SPs are new)

Something appears to be happening on cylinder 5 that messes up the spark plugs.  I'm going to try to clear codes and reset DME adaptations, but leave everything where it is.  I'll see if they come back as 3 and 5 misfires again.  If so I'll move 5 spark plug to another location to see if that follows.  

Maybe something with the wiring harness or could be computer related?  Ugh.  

Would love to get this sorted out.  I don't have anyway to live monitor stuff while the engine is running to see if it is truly misfiring or look at other parameters.  I think that's the next step.

[B C]

what does the cylinder 5 spark plug look like compared to the others?

I would be interested to see if by chance the o2 sensor connectors for bank 1 and 2 could have been mistakenly switched. I am not sure if  wiring lengths and locations would allow that to be possible or not.

[cpandrewschmidt]

they all look same to me.  I'll take pictures next time I have it out to show you.  I'll be gone this weekend putting the vert into storage so won't have time to mess with it till Sunday.

[cpandrewschmidt]

Hi all, quick question.  I replaced my RTABs this weekend.  After I got done I discovered some threads talking about preloading them.  I understand the concept and why to do it.  Now I just have to figure out the proper way with out the BMW tool.  Only it says use a straight edge and measure 8mm above the center of your hub.  My questions are:

1.  my car is lowered.  Should i error slightly more than 8mm?

2.  do you measure with the car fully jacked up?  won't different cars with different suspensions sag more or less than others, throwing off that 8mm measurement? 

3.  do you measure for below or above the center of the hub?

I attached some pictures for reference of what I was doing.  I was going to measure above center of hub, but still unsure of question #2.  I think i tighten it too far off 8mm trying to account for my drop in suspension.  I was getting a bad shake this AM from the one side i messed with.  Will try to correct tonight. 

Thanks for the help for anyone who's done this. 

[jc43089]

You replaced them with stock ones?  Just checking because poly ones rotate so it doesn't matter.

[cpandrewschmidt]

yes, stock w/ limiters.  i got some tips on bimmerforums:

"Don't fully tighten the bushings bolt.
Install RTAB bracket to car, install wheel, lower car to ground.
Drive the car back/forward 10ft or so so the suspension can settle.
With a marker (pref a paint marker) reach into the RTAB bracket area and draw a line across the bracket relative to the trailing arm.

Put the car back in the air, remove RTAB bracket and you should now be able to line the RTAB bracket to the line you just drew. Now tighten and torque the bushing bolt. Tada!"

[m42b32]

cpandrewschmidt said:

yes, stock w/ limiters.  i got some tips on bimmerforums:

"Don't fully tighten the bushings bolt.
Install RTAB bracket to car, install wheel, lower car to ground.
Drive the car back/forward 10ft or so so the suspension can settle.
With a marker (pref a paint marker) reach into the RTAB bracket area and draw a line across the bracket relative to the trailing arm.

Put the car back in the air, remove RTAB bracket and you should now be able to line the RTAB bracket to the line you just drew. Now tighten and torque the bushing bolt. Tada!"

Another option that I would guess would work, is to determine just how far you are lowered from stock in the rear. That number is easy to find if you have lowering springs as it should be a published value, less so if you have adjustable suspension. If you've got coilovers, there are published values from BMW for stock ride height from the ground to the wheel arch (or something like that) that you can compare to. If I'm thinking correctly, measure down from the center of the hub by the amount you are lower from stock ,and then up 8mm from that point to set the preload relative to your ride height. 

As far as the vibration, unless your alignment is really out of whack, it is most likely that the new RTAB is 'uncovering' and issue elsewhere by transmitting vibrations that were previously being absorbed by the worn bushing.

[cpandrewschmidt]

m42b32 said:

Another option that I would guess would work, is to determine just how far you are lowered from stock in the rear. That number is easy to find if you have lowering springs as it should be a published value, less so if you have adjustable suspension. If you've got coilovers, there are published values from BMW for stock ride height from the ground to the wheel arch (or something like that) that you can compare to. If I'm thinking correctly, measure down from the center of the hub by the amount you are lower from stock ,and then up 8mm from that point to set the preload relative to your ride height. 

As far as the vibration, unless your alignment is really out of whack, it is most likely that the new RTAB is 'uncovering' and issue elsewhere by transmitting vibrations that were previously being absorbed by the worn bushing. 

note to my idiot self.  it usually helps with vibrations to actually tighten lug nuts.............

rtabs all better now.