Can the VANOS timing be checked without removing the valve cover? Yes!

[sapote]

It can be done by capturing the crank and cam signals using a digital scope such as PicoScope or similar pc based relatively inexpensive scopes.

I'm working on finding the TDC offset relative to the missing tooth signal of the CKP, IOW how many degrees offset after the missing tooth on the crank wheel to the TDC. The only reliable way to find out is to look thru the CKP hole and count how many teeth after the missing tooth to get to TDC (timing mark on crank damper). The crank wheel is a typical 60-2 timing wheel.

The EX cam has the 7 teeth wheel -- 6 equal spaces and one long space. This should provide 6 small pulses and 1 long pulse. The unique long pulse is used to differentia between crank compression cycle or exhaust cycle. The long pulse also used as a reference to measure cam timing.

The IN cam has 6 teeth equally spaced, so it cannot be used to differentia the two crank cycles. The 6 pulses are used to trigger injection and fire the sparks for each cylinder. Any of them can be used to measure the cam timing electronically.

Who can help to find the TDC offset teeth count thru the CKP sensor hole?

[heinzboehmer]

You're also going to have to account for whatever the VANOS is doing. Think those values are all obtainable with a single D bus command.

Actually, you might be able to work out the timing with crank position, cam position and VANOS targets all from D bus.

[maupineda]

Yes, do an ISTA, tool32 or DIS test. That way you don’t get your hands dirty. I mean, you don’t even pop the hood 🙃

[sapote]

Actually, you might be able to work out the timing with crank position, cam position and VANOS targets all from D bus.

If the VANOS is working then maybe Dbus can answer the timing I'm looking for, but when it has an issue, i.e. I have error code 0xA and 0xF crank/cam synchronization issue for EX cam, then can we trust DIS to give the correct data given the vanos solenoid valve might be not working and so the cams might not follow the DME position command. Also does the DME know the exact cam timings when the vanos pistons are touching the front caps, as this is not a position in the operating range, because I don't think the designers would allow the piston to hit the cap in a closed loop control, unless this is not a position within the [-83 to -128] operating range.

So to check the timing, I would open both solenoids to drain the oil for EX cam by driving them with some safe current (open it with a quick 12v touch on the pin, then lower the voltage down to 5v or whatever needed to hold the valve open), then manually turn the crank multiple turns CW to ensure the piston is pushed to the cap (or close the advance solenoid and open the retard solenoid via applied current, and pressurize the vanos with compress air via the banjo fitting to ensure the piston moves to the cap) , then turn the crank and read the relative position of the EX cam pulse to the crank TDC pulse to get the cam timing at TDC.

[sapote]

Yes, do an ISTA, tool32 or DIS test. That way you don’t get your hands dirty. I mean, you don’t even pop the hood 🙃

Yes, but this assumes the solenoids, the cams and crank sensors are working. I.e when I have error codes hex A and F, I don't know exactly what's wrong; could be cam timing is wrong, or solenoid and sensors is wrong, so normally we open the VC to verify the cam timing, but I want to verify this w/o open the VC.

[BL92]

While we are on the subject, can we not just replicate the vanos special tool? plug is avail, just need to open up the device and see how it works

https://www.pelicanparts.com/More_Info/BM126050.htm?pn=BM-126-050&srsltid=AfmBOorJvHw0qAkjFVl0q_1lIQDBzsWIFJnNjftHi1zhvLKIb_Ig1ssL

[sapote]

While we are on the subject, can we not just replicate the vanos special tool? plug is avail, just need to open up the device and see how it works

Its purpose is to open/close the solenoid valves so the compressed air can move the pistons to the max retard position while rocking the cam with the 24mm wrench.
There are 4 wires in the connector to open each of the valves.

P1 green: Intake drain valve to retard
P3 black: Intake valve open to advance
P4 green: Ex drain valve to retard
P6 black: Ex valve open to advance

So to move the EX piston to retard: P1 should be 12v and and P3=0v with compressed air applied
To move IN piston to retard: P4 = 12v and P6 = 0v with compressed air applied

If the solenoid pins cannot be accessed, then I would connect the harness back to it and access the wires at the DME connector with the connector unplugged from DME. They are female pins so it's easy to insert a pin and apply voltage to it.

Note: initially apply 12v and after the valve opened with a click, reduce voltage lower to avoid overheat the solenoid. Of course don't lower the voltage too low that it causes the valve to close.

I think this's all the BMW tool does.

[BL92]

Awesome info, Thank you

Quite easy to make 1 up then

[sapote]

Awesome info, Thank you

Quite easy to make 1 up then

I would just get the 4pin female connector with 4 wires and label them with IA, IR, EA, ER for intake adv, retard, and exhaust adv, retard, then just apply power directly to the wire as needed.
I checked today by measuring the resistance from the DME pins for each solenoid: 7.2 ohms from each wire to engine gnd. The each solenoid one end is grounded internally. The solenoid clicks with 7v applied and hold with only 5v so no chance of overheated.

It makes louder click (by the loading spring) when disconnecting power than when applied pwr (less net force = F_magnet - F_spring)