floss_regularly Posted February 8, 2013 Report Share Posted February 8, 2013 Hey all, yes, I've looked in all the other posts so far relating to this, but I'm none the wiser....and £400 down. I have a rough idle and poor running under 2000rpm (bogs down, hesitates etc). This has actually got worse over the past couple of days, that I'm hearing knocking noises coming from the engine bay. When lifting the oil cap, other than getting a facefull of oil spray there is an obvious rattle noise (but not horrendous like many sound on YouTube), and no obvious suction (which I understand there should be?). Add to that my idle rests at 600 rpm which seems too low, and the needle itself dips very slightly every 10 seconds or so. There is also a whine coming from the car when I reach higher revs if accelerating hard. Have replace CPS, fuel filter, coils and spark plugs and there are no fault codes coming up..... this weekend I intend to look for split pipes and unplug the MAF. From there, I'll attempt a Throttle Body clean and head for the ICV - any DIYs on these as I can't find any on here. Over to you - any other suggestions welcome....some say VANOS, others say that my engine doesn't have it!! Cheers, Floss Link to comment Share on other sites More sharing options...
marc l Posted February 8, 2013 Report Share Posted February 8, 2013 Not from my own experience but people on here have trouble with cam, crank and air flow sensor. Has it been hooked up to a laptop for diagnostics? Link to comment Share on other sites More sharing options...
floss_regularly Posted February 8, 2013 Author Report Share Posted February 8, 2013 yep - no codes....that's the bit that confuses me! Link to comment Share on other sites More sharing options...
Mark7775 Posted February 26, 2013 Report Share Posted February 26, 2013 Mine was the same...no codes,so I did my own investigation by unplugging sensors whilst the engine was running to see what would happen. Needless to say I've now replaced both cam sensors and everything is now tip top Link to comment Share on other sites More sharing options...
Ginger Posted February 26, 2013 Report Share Posted February 26, 2013 Who said your engine doesn't have vanos??! You have twin vanos my friend. and no icv! With the n42, it is difficult to determine causes of air faults, as the engine can adapt to airleaks quite well. A hole under the size of a 5 pence piece can be delt with! First thing I would do is put the vvt system into emergency mode (by unplugging the eccentric shaft sensor that's by the oil filler neck, under the Bmw branded engine cover) this will cause the vvt motor to put maximum valve lift into effect and control idle with a throttle butterfly (instead of the inlet valves doing it) if idle and throttle response improves, then you know you have probs with your eccentric shaft and fingers. If not..... Leave the engine as it is (in emergency mode, vacuum will be present in the intake system now) and have it idling, and with some brake cleaner, spray around the intake system. If revs increase as you spray in a certain point, it will be in that area that you have an airleak. BE SURE TO NOT DO THIS WITH THE ENGINE HOT AS IT IS A FIRE RISK!! Common points to cause airleak issues are...the ccv unit (normally also causes high oil consumption) and the ccv breather link pipe which collapses (it lives under the engine cover that's on the nearside) It's easy to pull off and check. If you can't find an airleak, then you could have sensor degradation or even timing issues. I would work in a hitlist fashion, crossing off the things you have done, so you don't go over the same stuff. marc l 1 Link to comment Share on other sites More sharing options...
Had0uken! Posted February 26, 2013 Report Share Posted February 26, 2013 Not read the whole topic as im kinda lazy, when I first got my N42 318 'vert last year it had a slight hesitation when setting off, like it'd bog down and be almost dangerous when pulling out of junctions. Got Progman hooked up on my computer and updated engine software and it cured it like 75% so might be worth a shot? although that doesnt explain any mechanical noises you heard! Link to comment Share on other sites More sharing options...
Hanynowsky Posted August 24, 2017 Report Share Posted August 24, 2017 On 2/26/2013 at 21:08, Had0uken! said: Not read the whole topic as im kinda lazy, when I first got my N42 318 'vert last year it had a slight hesitation when setting off, like it'd bog down and be almost dangerous when pulling out of junctions. Got Progman hooked up on my computer and updated engine software and it cured it like 75% so might be worth a shot? although that doesnt explain any mechanical noises you heard! Hello There Had0uken. I really am desperately looking for how to update my N42 software to solve the same issue. How did you do it? Link to comment Share on other sites More sharing options...
