BMW vacuum leak/rough idle

[@jasonmcdonald7280]

Check the vacuum hose from the intake elbow to the fuel regulator on your fuel filter.

[@acewelding]

I had this. It was the small vacuum hose off the MAF hose elbow

[@psavel274]

Was going to say the same thing. Usually on the m54 the small pleated elbow that goes to the ICV is the first spot to crack. Id replace both boots, clean the MAF, ICV and throttle body while I was in there. Check the shitty CCV hoses and valve for cracks as well. The separator is a known failure point, and I prefer to delete them and run a proper catch can setup.

[@OLearysBMW]

It's obvious that it will run rough once you pull the oil cap off whilst engine is running. You're creating a giant vacuum leak. The CCV is a sealed system.. I know this video is old. But, just saying.

[@CL4RK1Eakog]

Yes but if there was no vacuum leak elsewhere the oil cap would suck the palm of your hand

[@OLearysBMW]

​@@CL4RK1Eakogyou can hear the light suction once he removes his hand, if you listen closely. A properly working CCV of M52TU/M54 has little crankcase vacuum at idle. Either way, if you remove the oil cap with stock CCV system, you're introducing un metered air into the crankcase.

[@Dat550go]

It is your Brake booster. You're welcome. ✌

[@tyronearchibald8868]

Yes my brake booster is making a bubbling noise and roughy idle sometimes misfires

[@gavn653]

mine is having the same problem lmk if you figured it out thats spot on what my car is doing

[@mrbugatti95]

did you figure out the place of the vacuum leak?

[@yeboi2217]

That looks like ICV OR CCV

[@johnberry9415]

The last noise air ? or what ?

[@jeroenstoelinga]

DISA valve is broken!

[@steviepere1822]

Check brake booster

[@zombienumber26]

Could vacuum or maf sensor being shotty, also do a seafoam treatment or just change that oil I hear ya shit ticking

[@sarahminifie8592]

That sound is undoubtedly a vacuum leak so either get a smoke machine or search KZbin for other ways of finding vacuum leaks but I’ll bet most of them are cracked elboy joints on the big hose that connects to the throttle body, then the Disa the the 6 other little hoses it’s not much work to check hose by hose I can do it in 20 minutes so can you.

[@downzyndrome2794]

I have a z3 and mine is doing this

[@rodbender6184]

Puka puka puka noise sometimes fading off and on is the disa valve. Even though it runs fairly smooth. Sluggish acceleration is another symtom. Be running like silk with a new ccv.

[@bronsonedward]

Did you figure out what the problem is? Mine is doing exact same thing.

[@bakerz1121]

Its been 4 years, did you manage to figure out what was wrong? I'm currently having this same dilemma with my bmw :\

[@baselkaskas2093]

@@bakerz1121 small vaccum hose off the MAF elbow below

[@XxGreedyMagiiCxX]

​@@bakerz1121 same did you find it?

[@annonamouslyannonomose8553]

mine too and the outcome is??

[@sarahminifie8592]

annonamously annonomose for me it was the Disa

[@mrdeecov]

yep my e39 m54 is doing this too, anyone find out what fixed it ?

[@sarahminifie8592]

mrdeecov check your Disa valve

[@mrdeecov]

@@sarahminifie8592 have done, functions fine and new 0-ring fitted