1998 E36 2.5 Idle and Sticky Vanos Problem? Help!!
 

I have been working on this 1998 e36 for the last month and cannot figure out what the problem is. It started with a simple head gasket replacement when a customer of mine brought his car in with a leaky head gasket. Then, He purchased Euro cams and asked if I whould install them, I said sure (He told me they could be installed with no other mod's he had researched) So, I did the installation according to the guide on this site, (I already have the cam holding tool, TDC pin and Tensioner tool from previous jobs and they were used) My problem is, Now that it is all together It idles very rough and starts hard, First, I rechecked the Cam Timing and found it to be off on the intake cam, Corrected it and it Seemed to run smooth untill I revved it up, when it came back down to Idle it was running rough again. Could the vanos unit being stuck fully advanced cause this to happen?
Or do the euro cams cause known problems on Idle? I have Checked cam timing and it seems to be good now. The vanos unit is the spring and thrust washer type. I have been chasing this problem for a month now and am wondering what you guys think. any help whould be appreciated
Thanks, Nick

was battery disconnected at firewall? I would be looking first to see if their were any fault codes which would be your guide for further inspection. if not I would be looking at DME, if battery was disconnected does it not need time to relearn?

Hi, Battery was disconnected during work and then driven at least 15 miles on test drive a few times. also I havnt got any codes since the start except an O2 heater ckt malfunction and that was fixed by a replacment O2. I should also mention, it is hard to start like the timing is off and it pops in the intake but I have checked the cam timing multiple times and it is right on. That is why I came to you guys
Let me know what you think...
Thanks

There's a factory update that skews the timing slightly on the intake cam (I think it's the intake) to help with a timing problem that some of the early cars had. It may be that you have this issue, although it's probably not likely.

I would guess that the timing is off due to a problem with the VANOS unit. Disconnect (if you can), the electrical connection to the VANOS unit and see if that makes a difference in the performance of the car (it should). If no change, then I would probably suspect that the VANOS unit is indeed stuck...

Let us know what happens...

-Wayne