2.0i 2005 misfire

D

DuggyZ4

Member
Hello, I have a problem with rough idling on a Z4 2005 2.0i engine.
The last fault code read P0015 which indicates the vanos solenoids. To date both have been removed and cleaned as per u tube. Both operate well, solenoid resistance is 11 ohms the valves open and close perfectly using 12volt battery. Starting the engine it runs smoothly but after a few minutes the vanos solenoids kick in and it simply will not idle.
To make it run, and it runs well but I guess short on top end power, I have disconnected the two leads to the solenoids. With the engine running at idle both leads are permanently giving 10.5 volts. Is it possible the camshaft position sensors have failed or am I missing something.
 
Sounds like you've covered the electronic side well, have the seals been replaced? I recently replaced mine as a precaution (other car), although they seemed to be working well the new kit made a noticeable difference.
 
Thanks all, sincerely very helpful.
Heads all over the place but with your advice think I should be stripping out both vanos units, noting the shaft securing bolt has LH thread. Changing the seals, checking for mechanical damage.
Get this done and if problem still persists look to resetting (I think it's called ECM) after that scrapping seams an ideal solution to save me from bankruptcy.
 
Could be either your valvetronic motor or your eccentric shaft sensor. Read my previous post. The only difference with my predicament was if my valvetronic motor was connected ( ie the plug in the back of the motor was plugged in) my engine ran VERY badly, therefor I surmised that the eccentric shaft sensor was sending bad cam position signal/information to the motor making for very poor idle and stuttering when driven...
However by randomly unplugging the motor I could leave the cam in an acceptable position for the car to run ok, kind of what you are saying your car is behaving like at the moment. However I got poor fuel economy, poor idle and decrease in torque/smoothness with it unplugged.
As soon as I put the new eccentric shaft sensor in it cured all my problems..
I believe you can check the motor by running a meter across the 2 terminals and it should read something like 5 ohms, check it out on you tube. .... good luck sorting it out, unfortunately a lot of car manufacturers add a lot of gubbins on their cars to get them to pass emission legislation which makes then a nightmare to sort out as they get older
 
Thanks Andrew. The eccentric shaft sensor had been removed a month ago to fix an oil leak. I'll start with this over the weekend. I'll also find your posting regards the motor.
 
DuggyZ4 said:
think I should be stripping out both vanos units
Click to expand...

Hi duggy,

The vanos units on the N46 are sealed units. They are of a different design to the vanos used on the 3 litre engines.
These units can't be rebuilt but also don't suffer the same seal failure.

My guess would also be leaning towards the valvetronic system, camshaft sensors or timing chain problems but without proper diagnostics and live data, you can end up spending a lot of money on parts that are not needed.

The 2 litre engines can be flakey little buggers but are great when treated right :thumbsup:

Best of luck with your diagnostics.
 
Wonderful forum and thanks to all for your input help.
Well, I can only work on the weekend and Saturday removed the plastic camshaft cover to reveal all the components.
I actually have 1 spare camshaft sensor, so I'll slot that in the inlet side.
The valvetronic motor is disconnected and easy to check for the 5 ohm windings.
The eccentric sensor is removed and way beyond my expertise to say if it is Ok. However the sensor end was full of sludge so it's all cleaned up and put back in place. Of course the replacement cost is expensive and if memory is correct the fault codes recovered have not singled this part out.
So rather than spend I intend putting it all back together this Saturday and see what code(s) comes up if any.
 
DuggyZ4 said:
I actually have 1 spare camshaft sensor, so I'll slot that in the inlet side.
Click to expand...

Hi Duggy,

It sounds like you have a multimeter at hand.
The camshaft sensors can be tested by back-probing pin 2 (I think it's the orange wire) and testing for 12 volts relative to chassis ground.
This voltage should drop to near zero when a metal object, such as a ratchet handle, is placed on the tip of the sensor. :thumbsup:

Whilst you have the cam cover off, check there is good tension on the chain and that the upper guide is not cracked.

Happy troubleshooting,
J
 
Cheers for that: camshaft tensioner and chain replaced a year ago. The chain & tensioner still looks like new.
I'll check the sensors as per your instruction.
 
Jfgoldfish said:
Cheers for that: camshaft tensioner and chain replaced a year ago. The chain & tensioner still looks like new.
I'll check the sensors as per your instruction
Click to expand...

That's good to know, these engines can throw all sorts of fits if the chain is loose.

You should be able to slip a thin piece of stripped solid core wire or similar down the back of the connector seal without damaging anything.
The little plastic cover just has to be popped off the back first :thumbsup:

I would test both sensors on the one connector to save you disassembling both.
 
Jfgoldfish said:
DuggyZ4 said:
think I should be stripping out both vanos units
Click to expand...

Hi duggy,

The vanos units on the N46 are sealed units. They are of a different design to the vanos used on the 3 litre engines.
These units can't be rebuilt but also don't suffer the same seal failure.

My guess would also be leaning towards the valvetronic system, camshaft sensors or timing chain problems but without proper diagnostics and live data, you can end up spending a lot of money on parts that are not needed.

The 2 litre engines can be flakey little buggers but are great when treated right :thumbsup:

Best of luck with your diagnostics.
Click to expand...
Where are the Vanos units located in the 2.0 litre, I'm trying to get my head around how the system works. The two solenoids at the front of the engine actuate oil pressure for the Vanos I guess. I have watched vids on replacing the seals on the 3.0 litre but there is little info on the 2.0... You say the seals on the 2.0 dont tend to fail which is good news....
 
Andrew Sheldon said:
Jfgoldfish said:
DuggyZ4 said:
think I should be stripping out both vanos units
Click to expand...

Hi duggy,

The vanos units on the N46 are sealed units. They are of a different design to the vanos used on the 3 litre engines.
These units can't be rebuilt but also don't suffer the same seal failure.

My guess would also be leaning towards the valvetronic system, camshaft sensors or timing chain problems but without proper diagnostics and live data, you can end up spending a lot of money on parts that are not needed.

The 2 litre engines can be flakey little buggers but are great when treated right :thumbsup:

Best of luck with your diagnostics.
Click to expand...
Where are the Vanos units located in the 2.0 litre, I'm trying to get my head around how the system works. The two solenoids at the front of the engine actuate oil pressure for the Vanos I guess. I have watched vids on replacing the seals on the 3.0 litre but there is little info on the 2.0... You say the seals on the 2.0 dont tend to fail which is good news....
Click to expand...
Running the two systems... Valvetronic and vanos together does seem a bit of overkill on BMW's behalf, and lots to go wrong... :x
 
Valvetronic and Vanos aren't really related to each other. The former eliminates the need for a throttle body and only controls the amount of valve lift. The latter does the valve timing in relation to the camshaft. Then you have dual DISA valves on some of the engines to alter the intake manifold length at different rpms 8)
 
Success at last, running smoothly and back to normal.
I changed the inlet cam sensor with a spare , checked the valvetronic motor, I did check for resistance but it showed only 0.5 ohm so ran it using my golf trolley 12v battery and it spun beautifully.
I'd like to thank all who contributed to helping sort out the problem a truly wonderful forum. Peter. :D
 
[ref]DuggyZ4[/ref], nice one Peter, good to hear that you've cracked it. As ever with the Forum we'd all love to see some pics of your car :-)
 
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