BMW N52 Common misfires, Rough Idle And Vaccum leaks symptoms Explained And How to Fix 

Fantastic, valuable information to save us money and keep us motoring!!!! Another 100 % gold video from a great channel!!!

Great Information..wish you were here in the U.S.A. you would definately be working on my bmw👍

I never comment on any videos. But I have to comment that you are the best I have watched on any car video so straight forward awesome !

thanks for the video it helped me to understand my car better and showed me where i need to work on my car :) greetings from germany

Fantastic Edification!!! Thanks!!!

Great video Dean. Keep putting them out. 👍

Well said about using genuine parts its a must for these cars

Thanks for the video. I have had my '08 BMW X3 for a little over a year and it just began idling very rough, whistling from the engine, and randomly stalling out (but starts back immediately once I am to safety). I plan to check all of you suggestions (and heed your warnings regarding non OEM parts) and hope I can have it fixed soon. Unfortunately I don't know what the previous owner of 12+ years has done to the car, but I know that the engine stopping while I am on the highway with my 2 kids, and another that will be here in 2 months Making 3, is not safe(quite scary) and the $ for OEM parts is well worth it if my children will be safe. Thanks again for the informative video and 🤞 here's to hoping I can get it fixed! Cheers 🥂🍺🍹🍸

Your a legend. I'm a subscriber.

Great video

very helpful videos great work..

100% true! Thank you for sharing your knowledge!

Great advice

You sir. Are a genius.

I've got lean bank 1 and 2 on my 2012 n51 60k miles no vacuum leaks runs good still just had check engine light

Great video.l My mechanic was putting in an N52 engine l recently bought asa second hand..When we started the engine we noticed it was returning oily water into the water reservior and assumed it was the oil cooler and bought an oil cooler.So he fitted the oil cooler today and when we started it we saw it had oily water bubbling up and down from the water bottle cause the water bottle was open When we checked the oil cap too had some milky like substance.Can it be the head gasket that's blown or even the cylinder head might have issues? But the engine sounds good except a rough idle.Possibly what may be areas l need to give attention to

yup this guy is spittin truth✌😁

You should do a Q and A so we can get some answers . Thanks DR.

Excellent but one more thing that you forgot to mention is to remove and clean the Vanos filters..there is 2 of them on the left side of the engine.

Hi , thank you mate for all the helpful information, my N52 engine runing very rich, O2 sensors reading is bank 1 Sensor 1 2.00v . Bank 1 Sensor 2 0.8v . Bank 2 Sensor 1 2.00v, bank 2 Sensor 2 0.8v . What you think any advice?, thanks

great video, as an above average novice i'd like to offer a suggestion on increasing subscribers; You should consider creating a playlist with dumbed down content for new bmw owners. It should contain very basic stuff. I remember trying to watch Nathan's videos a few years ago and couldn't follow because he'd skip through things which he considered basic. I think the majority of possible subscribers are people very new to DIY and are afraid of screwing up and so need to get their feet wet with basic content

How common is it for the fuel injectors to fail on N52 (2006 330i)? I have a misfire 29CF cylinder 3, changed coils and plugs, but still misfiring, very rough idle, stalling. Thanks

Thank you mate

hello thanks for the info, I have 535i and it has a really bad idle only when I start it for like 5 seconds I change the spark plugs and coils and the problem still there so I gonna check everything you mention on this video thank you

The eccentric shaft on mine was bad when I first bought it, but it had been bad for a long time because oil leaked through the sensor and wicked into the harness thus causing excessive resistance so now I have to get a new harness for it. So I would inspect the connector at every oil change and replace the sensor immediately if it leaks oil. My 2 cents

My 08 idle surges from 700rpm up to 1500 every 10 sec until it eventually dies. I replaced the valve cover but simply reinstalled the valvotronic I think you called it without re learning because it wasn't replaced with new. Maybe that is the problem. Been fighting this for 2 months now. I replaced all coil packs, plugs, fuel injectors, purge valve, crankcase sensor, both cam sensors, mass airflow sensor, and bench tested the vanos. 12 oms and cycle with 12vdc. I was thinking the cats were clogged so I hollowed them out. No emissions standards in florida.

Ya all you said is true only the original parts I do the same for my 523i

Thank you

hey doctor! Im having a misfire on cylinder 3 and 4, sometimes, cylinder 4 dissappears when i move the coils cables, im starting to believe its the complete harness, ive changed plugs, switch coils from its original position, still the misfire stays in the same cylinders. I also have O2 sensor code due to an oil leak. Is it possible for the misfire to be caused by that O2 sensor?

So you just have a e61 valve cover on your N52? And what year is your N52? I have a 2007 328i E91 wagon which I believe has the N52, right? Also, I have a intermittent misfire that is coupled with a whistling noise. What is usually the common problem for that? I see maybe a faulty pcc/pcv... am I right? and is this only fixed with a new valve cover instead of chipping away at the old one?.... thanks trying to narrow this down. I'll message you this question too for a better chance at a reply. THANKS.

I got a 325i 2008 e93 (n52 i think) and when i put my engine off it makes this sound: "pfffffffff" like a vacuum orsomething. I am reading that it is normal. What is your opinion? Greetings from netherlands.

I believe you did not mention the crank shaft sensor ? Mine failed and the engine was revving up and down by itself, spooky... Not really causing a rough idle though, it just had a mind of its own. It was a pain to change since it is under the intake manifold on the lower part of the engine block. However, you can change it by going from under the car if you got tiny wrists like me :)

I just bought a 06 330i. I replaced both disa valves and reinstalled the stock are intake because her had aftermarket intake. He said he just had the valve cover gasket done. How do i do the relearn of that solenoid. I'm going to replace the vano valves. Also they removed the secondary air pump so I'm getting p1415 code i need to get tuned out.

Hello. My car (2012 BMW 328i with N51) is having some strange problems. My car is having a bit of vribrations when idle and my fuel consumption has increased a lot. The only error that I get is lean mixture from all o2 sensors (before and after cat). I have changed the spark plugs and the coils. The car doesn't loose any oil. What could the problem be ?

Hello! Could you tell which is what module, because in my e61 I have some module which don't have a serial number.

BMW Doc, what about the CCV. You said in this video that you only like using BMW parts, but in the CCV video you did, you used an Amazon one that came complete with all the pipes for £66 yet in any brand at all the CCV itself is over £40 on its own, let alone with the pipes aswell. So how good is the Amazon one?.

I agree cheap parts don't my buddy found that out the hard way

I know this has nothing to do with this but I'm having a Transmission Malfunction message but I can still drive. I was wondering whats the 1st thing I should do before taking it to a garage . Any information would be great, thank you.

Great information but my e90 n52 is giving me cylinder 1 misfire when am driving and the rpm riches 5000

hi. i have x5 with n62 engine, and i am stuck with two faults: 285A and 285B, vvt gear monitoring, servomotor bank 1 and bank 2. i highly suspect a eccentric shaft position sensor, what are your thoughts? please let me know

My air filter box was unattached, would this be the cause of the cylinder 6 misfire I’ve been dealing with?

I have a 2c31 code on my 08 bmw x5 3.0 and I have replaced both o2 sensors, valve cover, intake manifold gaskets, disa valve, ccv hoses, spark plugs, coils, air filter and cleaned tha maf sensor, I also switched the injectors from bank 1 to bank 2 and checked fuel pressure and it came out good at 75psi. The code is still theres and every time I clear it, the code comes back after about 10 miles of driving. What else can cause that problem with lean codes ?

hey man I have got a 2011 f10 (n52) and every time i start my car it will start to vibrate after 5sec and the exhaust puffs air and you can smell the gasoline from it. but after few seconds the rpm picks up and the car stabilize it self. this happens everytime I start weather cold or Hot it would act in a similar manner. I suspect a vacuums leak, what do you suggest

great info, I have a n52 engine runs ok cold but when it warms up only in gear with the brake applied the tach jumps and runs rough. Any Ideas? Thanks

What are the common ones after a gasket valve leak repair I recently replaced one ignition coil do to a misfire but now there is a code p0174 too lean bank 1 and bank 2 any suggestion????

so i have a p0301, i swapped coils around and it stays on cylinder 1, my plugs are fairly new as i just did them last year, i also have a p0140 that popped up with this misfire, can no activity at bank 1 sensor 2 be related to my misfire? any help would be appreciated.

Can you please upload how to pull out and clean you cat slide as you said they can get blocked up

Hey, i have misfires if i stand before a traffic signal. I checked OBD it sayed: 2AAB variable suction->So I changed big DISA. 2A82 Vanos Inlet failure-> So I changed both Vanos. 2A2E with P0172 fuel trim meagre. You have any ideas?

Thanks

Help! Have a 2a7c code, rough idle in drive & cold start. Changed solonoids, Vanos solonoids, cleaned Vanos filters, cleaned MAF, oil filter isn’t missing the center part, what else could it be?

BMW Doctor can you help explain to me where is the fan relay for 2006 325xi n52 is located??? Please help thank you.

awesome video, you mentioned relearning the vvt motor, i have a 2006 330 and done the valve cover gasket but never re learnt the vvt. can that be why my car been stalling at red lights? can you please elaborate on how to relearn. thank you!

I got an 2006 x5. Driving me insane.. Ive replaced two intake hoses to include the elbow that had a hole. Reppaced coils, sparkplugs, MAF, secondary MAF. It still idles low and every few seconds I hear the engine idle up, then it slowly idles down again, jumps back up. My idle control valve seemed to have been clacking fine. I get the lean codes, check engine light ONLY when its at idle, or reverse. Any help? What junk!

Fantastic video question i have a 07 328i I change the valve cover an gasket plus spark plugs and now i have a rough idle an oil and smoke coming out of my exhaust what could be the cause of that?

At 6:24 what is this flap that your referring too , are you referring to one of the sensors , or that odd hole on the manifold? , please help I’m chasing my own tail after a cyclinder 4 misfire 2009 i328

my n52 started idling and running very rough, but it fixes itself after driving it for like 15 minutes, it happened right after i filled up with gas after i almost ran out of it, it feels as if one or more of the pistons where not running, id apreciate any help

Fukin love this guy he knows his shit

Hi , I have pressure coming through inlet valves on bmw 530D , what can that be ? Thanks

hi , i got this 330i and a few days after i got a few errors , 2a82 Inlet Vanos , 2a98 crankshaft intake . i ive swapped the vanos solenoids between them to see if i get another error but nothing . any ideea please

The only way you can own them cheap .. well reasonable is doing your own work.. buying used parts that you can get away with.. like interior parts that break. Also you need a bmw specific scan tool at minim that can do some coding and battery registration. Also use good German LL01 oil like Liqui Moly.. BMW Copland and other Pentosin fluids..I swear that’s what’s keeping my 195,000 mile N52 E90 leak free.. I’ve heard horror stories from cheaping out on the oil and other fluids.

I have a '08 328xi. When I try to start my car, the engine will either turn over, or it will start and idle rough for 1-3 seconds and then die. I plugged in my scanner tool and it said that there is a misfire on cylinder 3 and 4. I replaced the ignition coil and I'm having the same problem, but when I scanned the car again it's not showing those codes anymore. Any ideas? Thank you!!

My n52 2.5 has been showing codes of too lean on both banks. Could it be the pcv system?

Dr I been changing and changing Parts, THE FUNNY THING IS ONLY WHEN IS IN IDLE OR REVERSE (THE WORSE MISFIRE) DRIVE ONLY WHEN BRAKEING, now as soon you touch the gas is smooth, and only can back the missfire as soon I brake to the point the car stop. Any help Dr Is frustrated me

My e60 n52b30 stalls on acceleration only. Beside that, it runs smooth. No codes, no lean or rich mixture, smooth idling. Any ideas ?

I have this issue where every once in a while it idles rough at a stop light like goes up and down a tiny bit I’m rpms for like 5 secs then calms down, when driving however it drives and runs smoothly, also when the car cools down and i go to start it it takes a little longer to start than when it’s warm, today it took me two tries for some reason, and sometimes I smell gas while outside my car, any help? I know I probably have a gas leak but I came from an eclipse to a bmw 325i 😂😂 know nothing here anything will go a long way

I see you don’t have the engine cover on your N52. Is there a purpose for them? I ask because I’m considering removing mine. Would it hurt anything by taking off even temporarily? Thanks

Hi, How can i check the ignition coils ? Thx

Don't forget the bad camshaft ledge seals on the VANOS that can be also a root cause of malfunction on the N52

Great info. Also i wanted to confirm when you said if you remove or replaced the valvetronic eccentric actuator for 06-07 model, you dont have to program it and you just turn on the ignition cycle it 2 times? I owned a 06 330i e90 thank you.

M8, thanks for video, can you please share the website or dealer name to buy OEM parts at trade account cost? Thx

I bought a Maf sensor on Aliexpress and i have to say that thing is work perfectly almost for 2 years in the car...i don't think all chinese parts are crap, you need to know who you are buying from, a good company offering 2 years warranty or something like that...another thing that leaks is the fuel line around 200k..mine is leaking right now on engine and i have to replace...the car is a 325i e90.

My car really misses when accelerating. It seems to drive pretty smoothly when it gets up to speed but it struggles to get there. Just changed the spark plugs, do you have any suggestions or ideas on what could be causing this?

HI, BMW DOC , MY N52 revs fluctuates only at operating temp cold start its perfect , mechanic says its cam gear ,can this be true

Thanks for the video. I have a 07 Z4 3.0si. I changed the eccentric shafts sensor, BMW part. When I start it, the rpm is erratic for about 30 seconds and then settles down. It runs fine after that and idles smooth. Is this a problem? No codes are showing.

He has great information but he just talks tooooooo damn much. Just get to the point and the task at hand. But he always gives great information Nd he's a great help.

Hello, I bought a 330i e90 n52 last year with 97,000 mi. I’m now at 132,000 miles and have a rough idle. Got a code for cylinder #5 and checked the ignition coil. I wanted to swap it with #6 and noticed a hole on the valve cover . Would this be causing my misfire?

I have a 2008 bmw 550i e60 and I’ve got this code P2187 what you recommend me to do ?I’ll would appreciate the help 🙏🏻

My 07 x3 has rough idle, stalls at stops, loud high pitch whistling until i open oil fill cap because of vacuum suction. My eccentric shaft sensor is covered in caulk like someone tried to seal it closed.. i pulled it out and there was a bit of oil in the female part. Cleaned oil out good and hasnt filled back up.. any help would be appreciated. I cant drive it till i fix it and its driving me nuts!

I have a problem, when I start engine, he starts to jerk, but if he gets warmer after 5 minutes, that goes away. I let the vaults read out with computer and he said lambdersode failed after catalyst. So I changed that and I also changed the spark plugs but it still jerks.I really do not know any further.

OEM is better. I had a Denso coil pack go out with my 2002 Toyota Camry. Toyota uses Denso electronic parts. I bought a Chinese aftermarket just to get by for a few days. Big mistake people.... I had an “ignitior malfunction” code on Cylinder 2 within 3 weeks. The coil was firing, but it was erratic on the O-scope. While driving, If I even tried to go over 50mph, the car would shut down. I tagged along with a friend to the boneyard, and took some coil packs out of a dead Toyota, and bought them much cheaper than the stealership. That fixed the problem.

Hey can u answer a few questions for me

Any idea how much 6NGK for my 525i N52B25 $420.

Hi! Firstly- great channel and very helpful advice! My N52 is using oil after the pcv change. I’m now about to use Forte Seal Conditioner. Did it work on yours? Many thanks!

My car haves a maf code when unplugged runs good soon as I plug it back it runs rough change the maf sensor and I have the same problem

Please answer my question I’m a subscriber lol My car the rpms goes down and up only when I started and when I drive like 3 miles the car feels perfect even when you stop at the red light the car still feels great but if I shut down the and started again the rpms still go down and up and the exhaust make a weird noise like little pops? 😔😔 Help me pls!!!

is it true or a myth- that in an N51 SULEV you have to replace the entire gas tank when replacing the fuel pump and regulator? I had mine done at the dealer 2 years ago, and now im getting the same problems all over again.... fuel trims at 18%, slight loss of power and a back pressure when filling my car up with fuel. thanks in advance

I'm In the US, my car lost complete power all of a sudden, dealer said the fuel pump and control unit needed to be replaced as well as the spark plugs, when I picked up the car it was running rough and stalling , took it back right away and now they tell me it is the crankcase pipes that need replacement. That was yesterday, they still have not called me to pick up the car, does it take more than a day to complete the crankcase pipe replacement? I hope they don't come back to tell me it is something else now . Frustrating. My car is an 2006 E90 121k

Hello, my 2007 X3 2.5si with an n52b25a came with the long reach, single contact Bosch spark plugs i decided to upgrade to super 4 platinum Bosch plugs part FGR7DQP 0242236562 short reach after i watching your vid because my gas mileage was poor. The first the engine ran smoothly at idle when i drove for 2 km the rev counter started vacillating bouncing up and down even at idle so i ended putting back the old ones the single pin. what could be wrong?

H I have a p0012 and p0015 replaced both vanos solenoids with BMW dealer and still idles rough. I also hear a wistle sound from the engine only after driving for a while.

My n52 has a vibration at idle at 600 rpm’s. No check engine or codes stored. Drives perfect but at red lights you feel it. It not vibrating like theres a misfire from a coil

I just did my spark plugs on my 2007 bmw 328i but after long drives the car starts to make a whistling noise and it starts to shake when I’m stopped at a red lift

Goof video. Lots of good info. However, it is short on diagnostics. I have gone through a major n52 engine stall, limp mode failure. I have replaced the valve cover due to a verified failure of the integrated pcv valve - chirping noise though the crankcase seal. what manufacturer would make you replace the whole valve cover for a pcv value and potentially damaging the crankshaft seals. This should be a bolt off bolt on replacement. I will echo the sentiment that you should never use cheap Chinese parts with BMW. FCP Euro gets you high quality at a reasonable price. BTW, I don't work for them., just experience. Back to the original point, I replaced most of the parts mentioned: pcv/valve cover, eccentric valve sensor (148k miles and under the valve cover)., vanos solenoids, camshaft sensor, however I still have a rough idle when cold. I would like more information on how to diagnose rough cold idle. Vacuum leaks is my focus now. Like I said, good info but it takes the shotgun approach. Need better diagnostics.

my car has a whining sound and when warmed up my car shakes do you have an idea what is causing this?

My bmw 2007 convertible coupe n52 engine has been an headache, I’ve done it all. The car has a hesitation during start but turns on everytime, after turning on, for about 15-20 seconds it has a rough idle but the rpm’s don’t jump too crazy, after the 20 seconds of hard idling the car smoothens out as if it’s idling normal, the car drives smooth also, it’s only during start up and stops at stop signs sometimes but it’s not as a rough. I’ve changed everything, starter, all sensors I forgot the name but the one next to the starter, spark plugs, valve cover, all the gaskets, all ground wiring, intake gaskets, airflow filter, Im thinking of getting new fuel injectors but I’m scared to keep spending money!!! Anyone know the answer to this long lasting issue?

What if I get your update when I haven't replaced any parts and everything works ok?

I’m in London Essex with e92 Are you a mechanic I could do with somebody with your knowledge

Hey I’m having a horrible time trying to figure out what to do with my e60. I’m pretty sure I messed up a lot of my computers due to bad choice deletes. Is there anyway I can reset the whole car to how it was before I started messing with it on inpa? Lol

I got a 6th misfire, changed spark plug. Ignition coil, fuel injector. Still have the misfire

Where are you based?

Funny every time I go to the BMW dealership to pick up parts, I feel like they are going to throw me out because I don't look rich enough.