Engine noise - BMW Forum

TurboB3 · 10-21-2008, 09:54 AM

I had changed the fuel filter recently because when driving my car it would act weird. It only happens when i step on the gas when it boggs. Most of the time its bogging a lot, but then there are times when it will run clean. I changed the fuel filter thinking this was it, and it seemed to be fine. I had to keep it garaged for a while and 3 weeks after i did the fuel filter, now it is bogging again. Could it be the O2 sensor? Im at the end right now as to what this could be.

kandi08 · 10-21-2008, 11:45 AM

Alright mate.
Not a expert but that sound's like air starvation.
So good possibility 02 sensor.
Try running with out air box, this will confirm the box is not blocking air.
Don't drive it at same time just run.
The only other possibility could be cat box (cat convertor) on the exhaust.
If this has collapsed inside the exhaust you won't get the gas out!
Is there an eggy kind of smell?
Let us know
I'm prob way off anyway!!

marti5 · 10-21-2008, 12:03 PM

Could be your PCV valve or Maf

TurboB3 · 10-21-2008, 09:04 PM

The o2 sensor was replaced probably a year or two ago so Im not thinking it is that. Hearing the car more, i notice the sound like a gargling. Has anyone heard of that? I feel like it is either the fuel, or air intake somewhere.

kandi08 · 10-22-2008, 05:25 AM

Try unplugging the maf sensor, and run the car. Doe's it make a difference?
Could be fuel pump. Doubt it though.
Try and locate the gargling noise.
Sound's like a water problem with gargling, unless fuel is getting starved, and being replaced with air.
Let us know how it's going.

marti5 · 10-22-2008, 12:04 PM

When you unplug the MAF if theres no difference, then its shot.

TurboB3 · 10-22-2008, 04:45 PM

Ok I disconnected the MAF sensor and the problem got a lot worse. Its the same symptom, but really bad. Right now, my car can ride fine at low rpm, but once I actually step on it it gargles its way around. I got a video of it if i can find a way of posting that. Could this still be the MAF sensor, just taking its time dying?

TurboB3 · 10-23-2008, 04:29 PM

Ok, a few more things to note if anyone can help. After driving it again, I noticed that it will start driving like crap when i hit 4500 rpm. Once I hit that, then anytime I press the gas it gargles and has a nice vibration throughout the entire car. But before I get to 4500, the car will drive like a champ nice and smooth like. So has anyone gone through this before?

nnamdi · 10-29-2008, 08:16 AM

dude have u checked out the fuel filter on the fuel pump? does it start easily from cold? but dis "gargling" sounds like sum1 downstairs (exhaust) isn't happy. A friend had what i believe is dis "gargling sound" on his e32 535i, said it was d a bad port can't remember which on though.

tommo8ball · 11-17-2008, 05:12 PM

sounds like whats wrong with my 320i I've been working my way around the car cleaning this and that , after cleaning AFM and ICV its running a little better through medium rev range but as soon as you put your foot down it runs like on on 4 cylinders i know its not coils spark plugs etc or internal, if it was it would do it throughout the rev range and not only when you first take off and at high revs , ( i don't have a working instrament cluster so don't know what rev's just around abouts ) and wont rev over about 4800 - 5200 revs , car has no o2 sensor either so not that !