Intermittent VANOS Code 72 - Inlet late valve

[Pklauser]

Been getting an intermittent code 72 which is EVANOS (intake side) "late valve". Forgot to nab the INPA screenshot before clearing this latest time, but will update.

VANOS test per: VANOS test with INPA comes back normal, I'm achieving the full range on both cams, and response times are less than 300ms.
Car runs fine.
Solenoid pack is new BMW OE a year ago after getting a persistent code 72 that would return immediately after clearing.
Entire VANOS unit has Beisan seals and a redrilled pump disc. Tabs were intact last I checked.
Checked wiring from connector to ECU connector and have continuity on all 6 pins, including when twisting the wires around to check for internal breakages.

Any ideas or similar experience?

I'll keep this thread updated with what I find, but for now I'm still just driving the car.

[sapote]

Solenoid pack is new BMW OE a year ago after getting a persistent code 72 that would return immediately after clearing.

It's better to provide where code 72 was read from. INPA code 72 is different than OBD code p0072, and INPA lists the code under decimal, 72 in this case, and 48 as hexadecimal.

I searched for code hex 48: it says the IN cam is retarded. You should remove VC and do a timing verification.
To do: remove the solenoid pack to release oil pressure, turn crank CW front view, to TDC. Use 24mm wrench to turn the IN cam CCW front view (might need to rock it back/forth in order to push the vanos piston forward until it hits the front cap. At this position the cam vertical hole should be very close to 90 deg to the head VC surface. I think your cam leans to the EX side.

48

DME: Inlet VANOS, retard valve

mss54ds0

Motor Electronics

[Pklauser]

Sorry yes it's an inpa 72, hex 0x48.

Yea it's probably wise to take a look. Seems weird that it would get out of wack if it was previously ok though, no? Would that indicate the VANOS hub bolts weren't tightened enough when reassembling the VANOS last?

EDIT: Also if the intake cam was physically not timed correctly, then I wouldn't expect to see it hit 0° and 60° during the VANOS test, which it does.

[sapote]

Sorry yes it's an inpa 72, hex 0x48.

Yea it's probably wise to take a look. Seems weird that it would get out of wack if it was previously ok though, no? Would that indicate the VANOS hub bolts weren't tightened enough when reassembling the VANOS last?

EDIT: Also if the intake cam was physically not timed correctly, then I wouldn't expect to see it hit 0° and 60° during the VANOS test, which it does.

It could be marginal to begin with and then chain could stretch a little too, making it a little retarded to trigger the code.
As about 0 to 60*, I doubt the tool displayed the range this precise 0 and 60, even though the range is correct at 60 degrees.

If the timing is right on, then somehow the sensor output is delayed -- slow rise and fall times.

[elrichmeister]

I had this error code po up on on my car since bought it in 2021 every time i scanned the car. I did Vanos Bulletproofing with Kaiv in San Diego almost a year ago 7/24 and about 6k miles since the service this error has not come back. Sorry cant say what part exactly fixed the issue, but Kaiv did pretty much the whole gamut of Beisan updates, cleaned and re-built the vanos unit, also replaced Vanos hub bolts.

[Slideways]

Have you tried replacing the VANOS valve block with another one?

[Pklauser]

Have you tried replacing the VANOS valve block with another one?

Not since having the intermittent code. It was new with the new BMW solenoids.

[Pklauser]

Got the valve cover torn apart. Using the cam bridge, the exhaust cam is dead-on, and the intake cam is a hair towards the exhaust side. I have to lift the intake side of the bridge slightly to get it to slot in. According to Beisan's procedure, lifting one side of the bridge more than 0.5mm is out of spec. I didn't get out my feeler gauge, but it seemed like more than 0.5mm.

Tomorrow I'll get into the fun project of re-adjusting the timing on that cam, which I understand I can do without pulling off the VANOS unit and everything, so that's cool. Been years since I was in here and I've basically forgotten everything about how this stuff goes together.

Does this track with what you were thinking sapote, or were you thinking the alignment would need to be further out to throw the code?

[BL92]

Setting the final timing, Please read this post = https://nam3forum.com/forums/forum/m...011#post303011

Please before touching anything run the vanos test in TOOL32 = https://nam3forum.com/forums/forum/s...5697#post35697


Sounds like an oil pressure problem, was the original pump disk redrilled or was it exchange?
Vanos filter and pressure reg o'rings done?
What engine oil you using and how long has it been in there ?

[Pklauser]

Re-timed the hell out of it until the pin went in like butter. What a pain.

No code so far, but that's the neat thing about intermittent problems. At least now I know if it comes back it's not because of the physical timing.

[sapote]

1.Got the valve cover torn apart. Using the cam bridge, the exhaust cam is dead-on, and the intake cam is a hair towards the exhaust side.
2. Re-timed the hell out of it until the pin went in like butter. What a pain.

1. How did you get the cams to this point? Did you turn the cams to TDC using the 24mm wrench, or they already settled at the position? How did you know that the cams pushed the vanos pistons to their max forward position?
2. did you remove the vanos, or just loosen the IN hub bolts and finess the hub position relative to the sprocket? I would say this method takes more time to get it right than removing the vanos and bolt it back on the head to set the IN hub to time.

[Pklauser]

1. Rocked cams til pistons were all the way forward, confirmed visually, and you can feel/hear the piston hitting the end cap. Turn crank one rotation, loosen three bolts, turn crank rotation so now crank and cams are at TDC, lock crank with pin, loosen other three VANOS bolts. Gently turn cam, keeping an eye on the piston to make sure it didn't move. Tighten three bolts, spin engine one full revolution and check again. Challenge was that after the revolution it'd be out again, which I recall being a challenge when I did this years ago. After some iterations, I got it.

2. That could be, but I don't have another VANOS gasket on hand, and I need to drive the car this weekend. In my head this was the easier way, but maybe pulling the VANOS would've been.

[sapote]

1. Challenge was that after the revolution it'd be out again, which I recall being a challenge when I did this years ago. After some iterations, I got it.

2. That could be, but I don't have another VANOS gasket on hand, and I need to drive the car this weekend. In my head this was the easier way, but maybe pulling the VANOS would've been.

1. You did it the right way. It will change because there is back lash in the vanos gear train when doing w/o having vanos pushing the gear train to zero the backlash, and how much slack on the chain pull side.

2. I understand about the vanos gasket.

Hopefully the IN cam timing is correct and no more code.

[Pklauser]

After several hours of driving, now I have a "230 Inlet target/actual comparison" error. 🙂

Hasn't triggered a light...yet.

Occurrence details translated:

"Zustand EGAS" - Condition EGAS - not 100% sure what this represents, and why there are no units.
"EDK-Steller Istwert" - EDK Actuator Actual Value - EDK is the throttle actuator, so this happened when the throttle was shut.

Bottom text translates to:

"don't close properly Error currently not present sporadic error" - Cool cool cool

This is pointing me to either VANOS internal seals, which were done with Beisan seals ~4 years and 40k ago, so that seems premature. Granted they weren't done by me, so maybe they were done wrong. Solenoid pack flaking out again, or the intake position sensor dying. Feels like Russian Roulette, any bets on where to start?

[Pklauser]

Oh duh, this says EGAS not EVANOS. This is an ethrottle issue, so completely unrelated to the VANOS issue. I was primed to see a vanos error!

Ok I'll chase this down separately from this thread and keep it on topic here.