[Jarninius]

About 2 days ago, i got my oil changed on my 2011 335xi. Not sure if it can be related to the issue, but the next day i noticed a very subtle knocking sound on the highway anytime i was going above 60-70MPH. I thought it was too quiet to be a knock and figured something was just flapping somewhere on my car (stupid of me). Today, I was down the street from my house and then i can hear my engine misfiring like crazy. It started off rough and quickly sounded worse. I only drove it for about 20 seconds just so i could pull it into my street and then i immediately shut my engine off. I pulled a code for multiple misfires, and my car reeked of gas. I know misfiring can be caused by many different factors, but does anyone have any clue what could possibly be wrong with my car? I’m really tight on money and this car is my only mode of transportation and i would like to see if there is snything i can do to disgnose the issue and figure out exactly what is wrong with it. My car usually takes about 2 seconds to start but some days it will take up to 8 so i’mnot sure if that can be traced back to my spark plugs or not. Any suggestions are very appreciated. I am open to any questions and will take any help i can get. Thank you all!

[Jarninius]

Something else i also noticed that day was that I could hear a very very high frequency ringing sound anytime my car was above 1000 rpms. It got higher pitched as the rpms increased but immediately went away as soon as rpms dropped off again. the ringing was very quiet and only noticeable with my music off.

[swellengear]

Difficult one to diagnose over the web, but if there is a strong smell of gas, I would guess at an ignition problem. (or perhaps a leak in the fuel delivery system)

If it were me, I'd start by pulling the coils and plugs, and giving everything a good clean. Then reinstall, and see if things improve. With the engine idling, also just double check that you don't have any obvious fuel leaks.

[Jarninius]

Originally Posted by swellengear

Difficult one to diagnose over the web, but if there is a strong smell of gas, I would guess at an ignition problem. (or perhaps a leak in the fuel delivery system)

If it were me, I'd start by pulling the coils and plugs, and giving everything a good clean. Then reinstall, and see if things improve. With the engine idling, also just double check that you don't have any obvious fuel leaks.

Idled my engine for about 5 seconds, it took around 10 seconds of rough cranking and i have realized my exhaust is shooting out white smoke. I’m thinking it must be a bad gasket or something, I have an experienced friend coming over tomorrow morning to try to take some stuff apart to further disgnose it. Keep you updated.

[jbellk75rt]

Originally Posted by Jarninius

Idled my engine for about 5 seconds, it took around 10 seconds of rough cranking and i have realized my exhaust is shooting out white smoke. I’m thinking it must be a bad gasket or something, I have an experienced friend coming over tomorrow morning to try to take some stuff apart to further disgnose it. Keep you updated.

Did you change the oil or have someone else do it? If someone else, I'd check oil level and look in spark plug holes for excess oil before removing any parts.

[Jarninius]

Originally Posted by jbellk75rt

Did you change the oil or have someone else do it? If someone else, I'd check oil level and look in spark plug holes for excess oil before removing any parts.

It was done at a valvoline shop. I checked oil level and it read max. I will check out the spark plugs when i get home tonight