[cmcshera]

When accelerating at a fast speed/rate (merging on highway) usually around 4th gear, car starts stuttering/struggling pretty bad. As I let off gas (still accelerating) it'll go away for the most part. But once I get on it, it stammers, but only in 4th gear or higher.

2008 328xi E92 124k

Any thoughts on what might be causing it?

[Big Mexican Women]

Originally Posted by cmcshera

When accelerating at a fast speed/rate (merging on highway) usually around 4th gear, car starts stuttering/struggling pretty bad. As I let off gas (still accelerating) it'll go away for the most part. But once I get on it, it stammers, but only in 4th gear or higher.

Any thoughts on what might be causing it?

Scan car. Replace all 6 spark plugs. Replace ignition coils on misfiring cylinders.

Might be helpful for us to know what car your have

[cmcshera]

Originally Posted by Big Mexican Women

Scan car. Replace all 6 spark plugs. Replace ignition coils on misfiring cylinders.

Might be helpful for us to know what car your have

haha my bad, I just put it in there. 08 328xi E92. I've scanned and I get nothing

[Big Mexican Women]

Originally Posted by cmcshera

haha my bad, I just put it in there. 08 328xi E92. I've scanned and I get nothing

You might want to also add your mileage.

did you use a comprehensive BMW scanner? your generic autozone car scanner will not always pick up codes.

try doing a full throttle pull to redline and see if you get a warning message for reduced power (your check engine light will come on saying reduced power but the light will go away once you restart your car) this is your opportunity to scan the car and check which cylinder is misfiring.

or, just replace all your spark plugs and ignition coils. this will almost certainly solve the misfire.

[Bimmer Pleaser]

if there are no codes and only it happens in 4th gear then it is probably a transmission issue. I know BMW does not recommend tranny fluid change but I had tranny problem with my old 328i which completely went away after fluid/filter/gasket change. My problem was different though.

[Big Mexican Women]

Originally Posted by Bimmer Pleaser

if there are no codes and only it happens in 4th gear then it is probably a transmission issue. I know BMW does not recommend tranny fluid change but I had tranny problem with my old 328i which completely went away after fluid/filter/gasket change. My problem was different though.

Doubt it

[Stage5Lurker]

similar thing happens with my n55 e92. It puffs a dusty brownish color smoke during the stuttering at wot. I recently changed plugs and got no codes when it happen.
currently dealing with stuttering after a delayed cold start. car starts tripping, rpms bounce and then it dies. Check all reachable vac lines-no issues. In the process of cleaning maf sensor now, next, not sure about how to go about check the pcv. Car does whistle somewhat which is why I thought pcv. Changed out the crank seal, ofhg/oc, new radiator, wp/therm and hoses.

[Big Mexican Women]

Originally Posted by Stage5Lurker

similar thing happens with my n55 e92. It puffs a dusty brownish color smoke during the stuttering at wot. I recently changed plugs and got no codes when it happen.
currently dealing with stuttering after a delayed cold start. car starts tripping, rpms bounce and then it dies. Check all reachable vac lines-no issues. In the process of cleaning maf sensor now, next, not sure about how to go about check the pcv. Car does whistle somewhat which is why I thought pcv. Changed out the crank seal, ofhg/oc, new radiator, wp/therm and hoses.

Open the oil filler cap while the engine is running and put a plastic bag over it. If there is suction, your PCV valve is all good. If the filler neck is not sucking in the plastic bag, you need a new PCV.

does your car have trouble starting, like it cranks longer than usual before starting? Sounds like you need a new fuel pump. Could also be fuel injector or ignition coil issue

[Stage5Lurker]

Originally Posted by Big Mexican Women

Open the oil filler cap while the engine is running and put a plastic bag over it. If there is suction, your PCV valve is all good. If the filler neck is not sucking in the plastic bag, you need a new PCV.

does your car have trouble starting, like it cranks longer than usual before starting? Sounds like you need a new fuel pump. Could also be fuel injector or ignition coil issue

Originally Posted by Big Mexican Women

Open the oil filler cap while the engine is running and put a plastic bag over it. If there is suction, your PCV valve is all good. If the filler neck is not sucking in the plastic bag, you need a new PCV.

does your car have trouble starting, like it cranks longer than usual before starting? Sounds like you need a new fuel pump. Could also be fuel injector or ignition coil issue

I checked all possibilities. Have yet to try the bag trick, but the culprit was intercooler coupling popped off. I don't think the clip seated correctly. I do hear a slight whistle upon acceleration so I am gonna try the bag. Thanks. I'll update and get back to you.

[JUMAS]

Originally Posted by Big Mexican Women

Open the oil filler cap while the engine is running and put a plastic bag over it. If there is suction, your PCV valve is all good. If the filler neck is not sucking in the plastic bag, you need a new PCV.

does your car have trouble starting, like it cranks longer than usual before starting? Sounds like you need a new fuel pump. Could also be fuel injector or ignition coil issue

He definitely needs a new fuel pump.

AND to test the PCV
this is copied from the pcv valve of doom thread:
"You can easily test the PCV valve for failure by holding a smoke source (match, cigarette) close to the hose barb with the engine idling. If smoke is continuously ingested into the valve the diaphragm is leaking. Alternatively you could check that tissue paper clings to the barb tip, or for absolute certainty you can attach a clear hose and see if motor oil or water is continuously drawn in. More scientifically you could apply 38mbar positive pressure to the barb with the engine off and confirm that the pressure is held for a reasonable time but few shops have the equipment for that. Do not connect a pressure gauge to the barb while the engine is running, you will interfere with the PCV operation and will not get any useful information anyway."

[hawkjr1]

Having the same issues with my 2013 328i coupe. Getting no codes so I will just drive it until a code pops up, Will pull engine cover off tomorrow and see if there is anything obvious can be spotted. Car has around 40,000 miles on it. Hope you find out what’s wrong.