Intermittent VANOS Code 72 - Inlet late valve

[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]

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?

[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.

[Slideways]

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

[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.

[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.

[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]

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]

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.