Vanos Error Code

[johnniepotpie]

Hey Guys, Don't have much BMW experience under my belt yet. Which I am happy to say after owning it for a year and a half. Looks like now I have an opportunity to roll up the sleeves and learn a little more about German engineering now though. The Check engine light on my '95 325iC has been going on and off periodically for a few months now, I figured the O2 sensor is probably going -its about due. Recently, the car has been stalling at stop lights and had some surging when sitting at an idle. Time to figure out what is going on. I followed the instructions on running the codes through the MIL on the dash. Came up with a 1266 -VANOS code. Okay, I study up on what VANOS is and seems pretty clear. What is not to clear is that I am getting an error code and the VANOS appears to be functioning properly. When I put my foot in it, the car accelerates nicely and seems to really come on around 3500 rpm. From what I have read, I'm feeling the timing change in the cam. So if it is working, why the code? And.. what is with the idle? Are they related?

For the fluctuating idle and the engine dieing at a stop light, My first instinct is to take out the idle control valve and see if it is gummed up, but it isn't exactly easy to get to and I don't have an error code. Any Ideas?

On the Vanos code, what do I check to see if it is Bad? Changing the Vanos unit does not appear to be beyond my abilities, but locating a new unit from a source beside the dealer does. Anyone know where to get a new or refurbished unit?

Thanks Guys for what ever help you can give.

-JPP

[blkongry]

Sounds like the code may be generated from a non-related problem... meaning it might be your idle-position-sensor (I think that is what is called) that is causing something to trigger the VANOS code. I'd go after the idle control valve or related issues before thinking there is something wrong with the VANOS. I have a '94 325iC and get a strange idle fluctuation as the car heats up or upon pulling up to a stoplight after a good open run. I've been keeping an eye on it, but it doesn't seem to be getting any worse nor causing any problems.

[Jeron]

You symptoms do sound like the ICV. We have discussed it here before and on the M3 pelican forum. If you dont find the threads let me know.

The VANOS code could just be the due to the stalling. Also, there is a sensor on the VANOS that could go bad. My M3 had some VANOS or cam position sensor code that I just cleared and it never came back.

[johnniepotpie]

Thanks Guys, I'll try cleaning the ICV and see what happens from there. I take it the ICV doesn't trigger a code of it's own??

-JPP

[Jeron]

Mine didn't throw a code. It just caused stalling and rough idling especially when cold. Cleaning it actually made it worse but that was good because it verified that I need a new one.

[johnniepotpie]

Thanks Jeron, I found an article on this site about checking the ICV and the Thorotle Switch resistance to see if they are working or not.

http://www.pelicanparts.com/BMW/techarticles/JF-Tech/BMW_E30_3_Series_Idle_speed_troubleshooting.htm

The thing is this data is for the E30 and I don't know if it is the same for the E36. Does anyone know?

Also I pulled off the ICV and it really doesn't look that dirty, but I don't know how clean it needs to be... Can I apply Voltage to it to see if it is working correctly?

[Jeron]

Test the resistance between each pair of the three pins. Two should be the same and the third pair should yield double. Then test resistance while moving the valve. It should not drop out, I think it should change steadily. This is where my failed the test.

To clean I used carb cleaner and q-tips.

The throttle position sensor is the same ohm test. It should move steadily from 0 to something without any drop outs.