BMW E46 318i idle issues

[Vicious_tuning]

Morning guys.

I have a 2002 E46 318i steptronic with the N42 engine. I recently had some trouble with my engine. While driving one night, i noticed my oil light came on and engine started idling roughly. Topped up with some oil that i had bought to do a service on the car. Engine still idling roughly got the car home.

The problem I'm having now is when I start the engine, it doesn't have a steady idle. It will fluctuate between 250 to 750 rpm and sounds like it wants to stall. If i press the gas pedal it, i basically have to play with the gas in order to get the revs up ( i have to hold the gas pedal foot down for couple seconds in order to pick up ) and once revs has picked up above 2000 rpm and keep her on a steady idle, everything sounds fine, it will even rev up as normal just as long as you don't take your foot of the gas pedal, which will cause the rpm to go back to it fluctuating between 250 and 750 rpm, and sometimes will even stall.
Also once i put the car into drive or reverse and give it gas to move, the engine will stall, but if do the thing where i keep the revs above 2000 or when i feel the idle is steady, and put it into drive or reverse, the car will somehow move (which is the same way i used to get the car home that night) but once you let go of the gas pedal the engine will stall. And with this been an auto. I'm not very keen on doing thAt.
I have changed my MAP sensor but that didn't solve any issues.
Hope one of you guys has some better insight of this matter. Any help will be appreciated

 

[momo1]

Hope no engine internals damaged with low oil issue... bearing knock etc..

could also be a fuel related issue, dirty injectors , fuel pump...

really hard to tell , I think best is to have diagnostics done..

 

[Vicious_tuning]

Well there didn't seem to be any knocking issues. Also had 2 other guys confirm that as well. Also i noticed the oil pressure light comes on whenever the car is idling rough (fluctuating between 250 and 750 rpm ) but once I rev the engine , the light will go off and stay off as long as the rpm don't drop below the 2000 rpm mark.

 

[Ricky318i]

I had a similar idling issue a few years back. Turned out to be the valve cover vent pipe that was squashed flat. It is #2 in the diagram below:

 

[Vicious_tuning]

Ok. I just had a look at that pipe. I will post pics. But i removed it and found the tip covered. I stand to be corrected but there shouldn't be any oil in there should it?

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Ok so it looks like oil is passing through the pipe and into intake manifold

 

[kilotango]

Ok. I just had a look at that pipe. I will post pics. But i removed it and found the tip covered. I stand to be corrected but there shouldn't be any oil in there should it?

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Ok so it looks like oil is passing through the pipe and into intake manifold

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that is part of the oil seperation unit (PCV/CCV) mate, so its normal to have oil in it. those pipes do however crack and cause major vacuum leaks, which can cause similar issues that you've described. try and look for cracks along them. basically you'll need to follow each of these pipes from the CCV/PCV system and check for oil on their sides, or around the end where they 'plug in'.

the bottom pipe goes back into the where the dipstick meets the sump, those pipes often come off, or stop sealing properly. its quite a common thing with these cars.

are you seeing white smoke out of the exhaust btw?

 

[Vicious_tuning]

No not really. No smoke whatsoever from the exhaust.

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Ok first image shows that pipe connects to the intake manifold. And the second image shows that where the pipe connects, there's oil. Is that a problem for oil to be going through this pipe?

 

[Spiro]

PM Me your contact detail

 

[kilotango]

No not really. No smoke whatsoever from the exhaust.

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Ok first image shows that pipe connects to the intake manifold. And the second image shows that where the pipe connects, there's oil. Is that a problem for oil to be going through this pipe?

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ok, just to clarify... these pipes will have oil IN them... thats normal. however if you're seeing oil residue on the outside it may indicate a leak. basically this whole system takes the vapour gases, extracts the oil and returns it to the sump.

the way to test for a vacuum leak is to get a can of starter fluid. start the engine and let it run, then spray around those areas where you suspect there is a vacuum leak...and if you hear the engine tone change, then you've got a leak going on.

imo, try and get this car taken in for further diagnosis... Spiro would be a good start. you most likely have a bad PCV/CCV system thats causing major vacuum issues. when this system goes bad, it can end up dumping oil into the engine (which causes the initial low oil light, and an engine that doesnt run properly).

good luck! and let us know how it goes :thumbs:

 

[Vicious_tuning]

I have a guy coming later today. Will keep you guys posted

 

[Vicious_tuning]

Update.

I had a guy come in and done a diagnostic . But trying to the start, it cranks but just won't start. Checked fuel, checked for spark. Still not starting. The only fault codes were " 283e - Variable valve gear-output stage enable line " and " 285a - Variable valve gear monitoring ".
We cleared those codes, tried to start but will crank but not start. Could i have a problem with me VVT motor.