basim07 Posted March 4, 2012 Report Share Posted March 4, 2012 (edited) A couple of days, after i changed the MAF sensor on my car ive had an issue with rough idling and eventually cutting out of the engine, both when stationary in neutral and when driving when the clutch is down. Almost had a collision with a lorry as the engine cut out as i was going around a corner when changing gears, managed to wrestle the steering wheel and restart the engine when i realised what had happened Ive just taken the ICV out and have cleaned it with Carb/Fuel Injection Intake Cleaner (O2 sensor safe) but the problem has remained. I suspect that the problem may be a vacuum leak as after doing research this can be characteristic of these symptoms if it isnt the ICV plus it happened immediatly after i changed the MAF, along with the fact when revving the engine it revs fine once i get it above about 2000 revs but below that sometimes it stuggles to even build up revs/ is unresponsive and cuts out i made a video of the problem just now and shall embedd it below and help would be much appreciated Edited March 7, 2012 by basim07 Link to comment Share on other sites More sharing options...
Wash Posted March 4, 2012 Report Share Posted March 4, 2012 Where did you buy the MAF sensor from? You should always get genuine OE parts because the cheaper ebay MAF sensors are crap and often don't work properly. Have you looked around the intake system for any leaks/split pipes? Link to comment Share on other sites More sharing options...
Wash Posted March 4, 2012 Report Share Posted March 4, 2012 You should get a diagnostic check done too Link to comment Share on other sites More sharing options...
basim07 Posted March 4, 2012 Author Report Share Posted March 4, 2012 the MAF wasnt a genuine BMW Bosch one (they wanted around £200-300 and me being a student wasnt in my budget) but i got from a reputable source which had sold many previously before and the reviews were positive also i shoudlve mentioned the problem remains when the MAF is disconnected aswell as for the diagnostic check, ive considered hooking it up to a computer at the mechanics but ive read that faults such as leaks can throw up error codes for a variety of sensors, which may be misleading, i thought id exhaust other options first i dont know where to begin as im new to all this and in the past altohugh ive done almost all work on the car myself im still a newbie, should i be looking at the pipes around the throttle housing? Link to comment Share on other sites More sharing options...
basim07 Posted March 4, 2012 Author Report Share Posted March 4, 2012 also ive embedded the video now if its of any help Link to comment Share on other sites More sharing options...
jcjdavis1 Posted March 4, 2012 Report Share Posted March 4, 2012 Hi. If you have a vacuum leak one way of finding out is if you take the oil filler cap off with the engine idling and there is no change to the idle then you have a vacuum leak. Also check replace the Crankcase breather pipe and valve at the rear of the engine below the pollen filter housing. If you have a leak check every hose not carrying coolant, not very expensive from the dealer as I did all mine. You will find all your parts here- http://www.realoem.com/bmw/partgrp.do?model=AL32&mospid=47631 Jim Link to comment Share on other sites More sharing options...
basim07 Posted March 4, 2012 Author Report Share Posted March 4, 2012 hey jim, il do the oil check now, i just cleaned the ICV again and put it back in and the car starts but the revs no longer bounce around, instead they gradually decrease over a second and the engine cuts out every time so the problems has got worse ive removed the ICV again now and given it another clean with a toothbrush and used a straw to get the cleaner all the way into the valve, just in case the first clean mightve just moved any stubborn material ive checked the intake boot? which is after the MAf and that is in perfect condition, no wear/cracks at all its dark now so tommorow il take a look at the CBP & valve and see what happens cheers Link to comment Share on other sites More sharing options...
basim07 Posted March 4, 2012 Author Report Share Posted March 4, 2012 update: after another clean of the ICV, the car starts up and remains started for about 10 secs befor but still cuts out after that time, but still better than before ## when the engine is started and i remove the dipstick, i hear no distinct hiss sound and the engin cuts out so does that mean a leak? Link to comment Share on other sites More sharing options...
s_spender Posted March 4, 2012 Report Share Posted March 4, 2012 Spray some cleaner into the little hole in breather valve when assembled and running, if the revs change the valve is faulty! Link to comment Share on other sites More sharing options...
s_spender Posted March 4, 2012 Report Share Posted March 4, 2012 Just watched your video it's got a massive air leak, spray carb cleaner around all the inlet system and any change in revs indicates the problem. Link to comment Share on other sites More sharing options...
basim07 Posted March 5, 2012 Author Report Share Posted March 5, 2012 does the whiining sound indicate an air leak? i assume reving the engine would overcome the leak and the bogging down of revs because of the massive mounts of air coming in which is why this occurs at low revs only? is there anything else i can use aside from carb cleaner? ive pretty much finished the can so any alternative? cheers Link to comment Share on other sites More sharing options...
Johnny 5C Posted March 5, 2012 Report Share Posted March 5, 2012 Hi. If you have a vacuum leak one way of finding out is if you take the oil filler cap off with the engine idling and there is no change to the idle then you have a vacuum leak. Also check replace the Crankcase breather pipe and valve at the rear of the engine below the pollen filter housing. If you have a leak check every hose not carrying coolant, not very expensive from the dealer as I did all mine. You will find all your parts here- http://www.realoem.c...32&mospid=47631 Jim This. And read this thread.. http://www.e46zone.com/forum/index.php?showtopic=29174&st=40 Link to comment Share on other sites More sharing options...
basim07 Posted March 7, 2012 Author Report Share Posted March 7, 2012 (edited) update neither myself nor a mechanic when looking broadly could find a vacuum leak although it hasnt been ruled out new symptoms - * when car warms up to half way between cold/hot, or has been driver for 15 mins, the problems generally disappear * while at mechanics, when revving the engine, the idle would get stuck while coming down from say 4000 revs, at around 2000 revs and remain there for a number of seconds at first then sometimes indefinately till i turned the engine off, also a couple of times it got stuck at when i revved it to 2000 revs then slowly started increasing itself so i had to shut the engine down the mechanic cant seem to figure it out, and another mechanic wants to put at diagnostic computer on it, but wants £30 just for this which is ou of the question for me at the moment, as i have no spare cash at all, so im gonna buy an OBD2 cable and associated software (inpa and ediabas) and run the diagnostic myself sometime this weekend once again can i stress this happened as soon as i changed the maf sensor earlier this week, and had none of these problems before that when i was using the old faulty maf sensor or when i was driving without the MAF plugged (a couple of months i did this for), the maf itself is correct and not faulty as ive checked by unplugging it and the problems are consistent from this i reckon it is related to the intake system? as in pipes/throttle body/idle control valve (which i did clean out using a toothbrush and a full can of carb/fuel injection cleaner (o2 sensor safe) if anyone has any suggestions of what it can be from these new symptoms then they would be greatly appreciated as itl save me from dishing out £30 tommorow when i buy the equipment) cheers Edited March 7, 2012 by basim07 Link to comment Share on other sites More sharing options...
Wash Posted March 7, 2012 Report Share Posted March 7, 2012 If you're planning on keeping the car then the £25 quid on the cable and BMW software will be some of the best money you'll ever spend on your car. You'll be able to diagnose most problems without any hassle or need to do any investigating. Link to comment Share on other sites More sharing options...
basim07 Posted March 7, 2012 Author Report Share Posted March 7, 2012 yeah thats what i thought, il happily spend it myself and have it for future use rather than dish it out to a mechanic for a one time deal plus i like the idea that i can program the car, e.g. in ways such as set doors to lock above a certain speed etc Link to comment Share on other sites More sharing options...
jcjdavis1 Posted March 7, 2012 Report Share Posted March 7, 2012 Hi. Diagnostic is the way forward, might be the Crankshaft Sensor = money. http://www.bmwpartso...MW-E46-Parts-/- For OEM Parts. Jim Link to comment Share on other sites More sharing options...
basim07 Posted March 7, 2012 Author Report Share Posted March 7, 2012 will the diagnostic tell me specifically it is the crankshaft? if it is that is Link to comment Share on other sites More sharing options...
basim07 Posted March 7, 2012 Author Report Share Posted March 7, 2012 whats strange is it takes 15 minutes (no exaggeration) of starting the engine, letting it stall, starting again, revving it, turning it off, and then a 10 minute drive where i floor it and the car stops showing all problems completely, its no longer sluggish and has full performance and acceleration once the temp gauge has reached half way / a tad above half way i dunno where this points? any ideas? i just need to be prepared financially for the outcome ive heard it can be the Vacuum Leak? Camshaft Position Sensor? Idle Control Valve? VANOS? (i dont know what this is, and whether it applies to me n my car but it seems to pop up alot when ive been looking through similar stuff) Link to comment Share on other sites More sharing options...
Wash Posted March 7, 2012 Report Share Posted March 7, 2012 will the diagnostic tell me specifically it is the crankshaft? if it is that is It won't be the actual crankshaft lol But it could be the sensor, and if it is the sensor then the diagnostic will definitely tell you that. Link to comment Share on other sites More sharing options...
Wash Posted March 7, 2012 Report Share Posted March 7, 2012 whats strange is it takes 15 minutes (no exaggeration) of starting the engine, letting it stall, starting again, revving it, turning it off, and then a 10 minute drive where i floor it and the car stops showing all problems completely, its no longer sluggish and has full performance and acceleration once the temp gauge has reached half way / a tad above half way i dunno where this points? any ideas? i just need to be prepared financially for the outcome ive heard it can be the Vacuum Leak? Camshaft Position Sensor? Idle Control Valve? VANOS? (i dont know what this is, and whether it applies to me n my car but it seems to pop up alot when ive been looking through similar stuff) It won't be a VANOS issue, I'm not sure if the M43 has VANOS but if it does, it was mostly the M3 with VANOS issues. VANOS is basically the name given by BMW to their variable valve timing (VVT) technology. VVT does things like reduce emissions and fuel, and increase things like BHP/torque etc. It's always recommended that if you ever experience engine issues, 99% of the time a diagnostic will point you in the right direction so buying the cable/software is definitely a worth while purchase. Link to comment Share on other sites More sharing options...
basim07 Posted March 7, 2012 Author Report Share Posted March 7, 2012 It won't be the actual crankshaft lol But it could be the sensor, and if it is the sensor then the diagnostic will definitely tell you that. sorry thats what i meant ahh okaay i will do that fore sure, gonna get it ordered tommorow, unless theres someone around manchester that wouldnt mind letting me borrow it for half an hour ahh okay so that vanos/vanos seal is out of the question? as well as ordering the diagnsotic kit tommorow, im gonna buy some WD40 (is this safe)and have another go at cleaning the ICV out, but more rigourously? and some more carb cleaner for the throttle body/butterfly valve, just in case it is as simple as a problem like that Link to comment Share on other sites More sharing options...
Wash Posted March 7, 2012 Report Share Posted March 7, 2012 (edited) You should use carb cleaner to clean out the ICV, its better than WD40 for cleaning out the ICV. I wouldn't worry too much about VANOS seals and that sort of thing for now. Edited March 7, 2012 by Wash Link to comment Share on other sites More sharing options...
basim07 Posted March 7, 2012 Author Report Share Posted March 7, 2012 okay, il leave the wd 40 for now and get another can of carb cleaner any advice in cleaning it out? i used a full size can a couple of days ago and a toothbrush but found it difficult to get through the bends and stuff inside the actual ICV Link to comment Share on other sites More sharing options...
Johnny 5C Posted March 8, 2012 Report Share Posted March 8, 2012 (edited) I still think vacuum leak. Its hard to see pipes which have split. The one from crank case to CVV had a nasty hole in it, but I'd never have seen it without taking it off. Fuel rail pipe was split by taking off the MAF too. My CVV was also knackered. Changed CVV and hose, cleaned ICV Cam Sensor and MAF now all OK. With the parts your only looking at an hours work. CVV hose: (Or a short length from Halfords) http://www.ebay.co.u...=item4cfee6f7a8 CVV: http://www.ebay.co.uk/sch/i.html?_nkw=e46+crankcase+valve&_sacat=0&_dmpt=UK_CarsParts_Vehicles_CarParts_SM&_odkw=e46+crank+case+valve&_osacat=0&_trksid=p3286.c0.m270.l1313 Edited March 8, 2012 by Johnny 5C Link to comment Share on other sites More sharing options...
jcjdavis1 Posted March 8, 2012 Report Share Posted March 8, 2012 Hi. It would be good practice to change all your Vacuum Hoses, I have and it was not that expensive from the Dealer. Jim Link to comment Share on other sites More sharing options...
