[willisodhiambo]

This car came to me with complaints of low power and smoking. Replaced valve seals. Tested valvetronic using ista, limp mode. Replaced motor, limp mode, replaced valvetronic assembly, limp mode.

Error is "valvetronic adaptation 1". Ista can learn end stops ONLY OF VVT IS MANUALLY SET TO MINIMUM. On start system goes to full open and stays there.

Tried a sensor from an N42 engine, same problem.

Options remaining are another sensor and another DME.

Anyone had such experiences? Am suspicious of sensor more than anything else buy why is it able to learn end stops?

[duss46]

Have you already checked the VVT relay? Other problem I experienced with an E90, the oil somehow flowed back to the DME, after replacement everything was fine with the valvetronic.

[willisodhiambo]

Have you already checked the VVT relay? Other problem I experienced with an E90, the oil somehow flowed back to the DME, after replacement everything was fine with the valvetronic.

DME looked dry, no oil seeping into it. Relay also OK. Tried a valvetronic unit from another car (E90) and limp mode disappeared with ignition on, system reset itself as expected and settled at 1.4mm valve opening as expected but limp mode re-appeared immediately we attempted to start, system goes to full open. Settles back to idle position with engine off.

End stops are learned ok. After cranking, valvetronic defaults to full open. I am suspecting the E90 sensor is not quite compatible with the E46 DME even though both are N46 engines so my test can not be expected to be reliable.

I am looking for a E46 N46 engine valvetronic. That is the only thing remaining. Not sure what is the issue with the current unit though, its either sensor or mechanical fault I think.

[srki7]

Have the Same Problem - i was the DME ECU -

[nguyennghi]

check camshaft timming?

[duss46]

Timing chain is also worth a look, we had a problem with an N52 VVT, after adjusting the chain I could set the values, till then it just opened fully.

[willisodhiambo]

So I got frustrated with this car,

1. Replaced with N42 valvetronic. Same thing
2. Replaced sensor with N42 sensor, same thing
3. Was beginning to think DME but electrical tests showed all OK.

In frustration returned the old valvetronic and a new motor. On ignition, it settled at near minimum, at crank it went full open but cover was off so quickly switched off. Decided I had had enough and tied her up.

Cranked engine and went to diagnostics, no limp mode! To this day I don't know what that was all about!!!