"Vanos mechanically stuck" code...

[DocWyte]

Just did a top end rebuild, motor was removed to do the work. So new valve seals/guides/springs, checked the head for cracks and made sure it was flat. Installed with new head gasket, ARP head studs, new Schrick 264/256 cams and a rebuilt vanos unit from VAC.

Initial shop couldn't get the vanos code to go away. Current shop found that the vanos had been installed 1 tooth off, which they corrected, cam timing is correctly set using the factory tools. Vanos is moving 9.2mm, which is the proper amount, plus the vanos is actually working, it's not stuck. Car runs great, with the exception of the code.

I've found that if I clear the code, it stays off for 1 key/run cycle, than on the next key cycle it pops back on immediately. I called VAC and they said to drive the car 200 miles, that the seal needs to work in sometimes.

I'm maybe 100 miles in, still the same behavior. If it still happens after another 100 miles, I'm thinking about calling VAC and asking them to send me another vanos unit.

Any other thoughts or suggestions?

[Carpy2]

I sort of remember reading somewhere that someone had this issue and fixed it. Maybe the bacon heater guy (blanking on his name)? I'll check to see if I can find it. I'm pretty sure it was due to a bad VANOS solenoid, so maybe test the solenoid for proper functionality.

[Carpy2]

I sort of remember reading somewhere that someone had this issue and fixed it. Maybe the bacon heater guy (blanking on his name)? I'll check to see if I can find it. I'm pretty sure it was due to a bad VANOS solenoid, so maybe test the solenoid for proper functionality.

Couldn't edit my post for some reason.

Found the thread. Bacon heater guy is Das Borgen lol. I remembered incorrectly, both his and his friend's solenoids did end up being functional. So they reinstalled their VANOSes and it works great now. I know you took yours to two different shops, but if you find it's no the solenoid, then maybe reinstalling it again is required. BTW, I have 0 first hand experience with this. I just recalled reading about this code a few years ago so tried digging up what I found. I would wait for the more seasoned pros to come comment and confirm or deny what I said before doing anything lol.

[DocWyte]

Shop verified that the vanos is moving/working. It would seem like the vanos timing is still not quite right, but its moving 9.2mm, which is how much it should move. Original shop had it installed a tooth off and it was moving 8.4mm at that point....

[Braymond141]

The second shop has not done it right. There is a “magic tooth” where the VANOS gear inserts immediately. It is not as easy as “one tooth off” and it can still seem right. I may of taken a video of this and will post it, but the intake side vanos spring assembly blocks being able to see it. A mirror works well.

Then there is the exhaust cam lock down procedure; this must be done with the air tool and 12v power to the solenoid. With the exhaust cam gear loose, cycle the VANOS on/off/on/off. Verify movement is correct and only lock down that exhaust cam gear after an on/off sequence ending in off. Using the lollipop hand tool in place of this will result in VANOS errors. This happens frequently.

[rajicase]

^^What? I have done this at least a dozen times and have never had to cycle the vanos solenoid. Are you saying cycling the vanos is required for correct installation? Cause it absolutely isn't. Maybe I'm misreading..

[Braymond141]

Yes yes. Given the amount of times this comes up I’m not including doing it by hand. If someone wants a guarantee that there will be no issues the first time, use the air and solenoid activation method.

[DocWyte]

Talked with the shop, they did have the exhaust cam gear loose. However, they're going to go back into it and get it working right.

[DocWyte]

Update! Shop found that the intake cam timing was too far advanced. They were able to play with the cam timing a bit and get the DME happy. Between that and having the vanos installed properly no more CE light...