[autoque]

I'm curious if I can just replace the valvetronic and vanos units or if the whole cylinder head must be replaced to be able to change the valvetronic/vanos.

And what are the parts cost like without the labor? realoem does not list the parts separately. They only list the price of the cylinder head with the valvetronic and vanos.

[Efthreeoh]

Go back to real OEM and search on this P/N 11377548388 (valvetronic actuator). You'll find the correct schematic and P/N list for the VANOS and Valvetronic parts.

[ctuna]

Are they bad in your car?
Typical thing that goes wrong with these is dirty vanos solenoids.
And as described in the DIY's they just need to be cleaned and reversed between intake and exhaust.

[galahad05]

Question: What are the "typical" symptoms of dirty vanos solenoids? How would I know?

[autoque]

Originally Posted by ctuna

Are they bad in your car?

Not quite sure, even after more than three years of trips to various dealers and master techs, no one knows what's wrong.

I've got a warm start rough idle which lasts one to two minutes after the ignition. This started right after replacing the cylinder head under warranty for a tapping noise, a well known issue in the N52 engine. They changed the spark plugs, coils, MAF and cleaned various parts, tuned up the timing of the valves, disassembled and reassembled, the symptom got a little better, but never disappeared. So my final desperate move, throw expensive parts at it, especially suspicious is the cylinder head unit, which started this long painful journey. I'm out of warranty so I'm picking up the tab, but the dealer's willing to forgo the labor cost since they know I've been having this problem early on. However the dealer doesn't know whether the replacement will lead to fixing the problem as their diagnostic device tells nothing's wrong.

The whole head costs like over $5000 so I thought replacing the valvetronic and vanos is more sensible to a rough idle problem. By the way, absolutely no fault code stored except a code was found about a month ago indicating an error with the vanos solenoid valve, so the dealer replaced it rather than cleaning it and using it again, hoping it would solve the problem. But no go.

[Efthreeoh]

Sounds like a bad valvetronic sensor to me.

[autoque]

Originally Posted by Efthreeoh

Sounds like a bad valvetronic sensor to me.

You mean the eccentric shaft sensor? Hmm, I thought about it and searched for others' symptoms but they have drivability issues whereas my vehicle's issue disappears within one to two minutes of warm engine start.

[autoque]

Originally Posted by Efthreeoh

Sounds like a bad valvetronic sensor to me.

Could you elaborate on the valvetronic sensor?