[Snoball M3]

Originally Posted by tdavis42

Could be the fuel regulator or fuel pump.

Thats what I'm thinking but I think if it was that it would've stalled during normal driving, but then I found out that my 328 has the N51 and I read they come with a 15 year or 150,000 mile warranty on emission related problems so Monday I'll find out if I'm qualified cause I hear some dealerships don't accept that, bit if they do I'll let you guys know what it could be and maybe fix our problem lol.

[tdavis42]

Originally Posted by RSKY65

Thats what I'm thinking but I think if it was that it would've stalled during normal driving, but then I found out that my 328 has the N51 and I read they come with a 15 year or 150,000 mile warranty on emission related problems so Monday I'll find out if I'm qualified cause I hear some dealerships don't accept that, bit if they do I'll let you guys know what it could be and maybe fix our problem lol.

I had my regulator crack and start sloshing gas out of the top and it still drove. It just had a strong smell of gas.

[Snoball M3]

Just got the car back, told me my DME needed an update and possibly replace the MAF sensor, that the DME codes dont set off lights to go off, but they quoted me 430 to update so if anyone else having issues might want to check that out...

[DaanBMW]

Originally Posted by RSKY65

Just got the car back, told me my DME needed an update and possibly replace the MAF sensor, that the DME codes dont set off lights to go off, but they quoted me 430 to update so if anyone else having issues might want to check that out...

So did you go ahead with it or not ? If you did, did it solve it ?

[Snoball M3]

Originally Posted by DaanBMW

So did you go ahead with it or not ? If you did, did it solve it ?

Not yet but I knew that wasn't the only problem so I took it to another indy and it also ended up being a damaged crankcase vent valve diaphragm causing an improper air to fuel ratio so I'd have to get my valve cover replaced that I and haven't been able too yet also my oil filter cap wasn't tight enough which was part of the idle too. Does anyone know if valve cover replacement is covered by the SULEV warranty?

[ZeroSum]

Had a similar issue until I changed my Vanos.

[DaanBMW]

Originally Posted by ZeroSum

Had a similar issue until I changed my Vanos.

changed vanos solenoids, camshaft sensors, vvt motor, maf, vanos check valves. result: no improvement.

[dstrickland]

Originally Posted by DaanBMW

changed vanos solenoids, camshaft sensors, vvt motor, maf, vanos check valves. result: no improvement.

What kind of hesitation is it? Like a rumble almost like a misfire when you take off?

[DaanBMW]

Originally Posted by dstrickland

What kind of hesitation is it? Like a rumble almost like a misfire when you take off?

imagine you step on the gas pedal to take off. you can imagine that what happens is the rpms go continually up until you feel the engine is revving so high that you should shift to 2nd. so basically the graph would be a continuously rising curve rpm = f(time).

mine would basically be a v. v. brief rpm rise, then a dip - a bog down, feels like a hesitation as it I suddenly took my foot off the gas but I didn't - after which the rpms finally continue the rise expected by the order via the gas pedal. so curve would be a Z shape: up - down - up again.

rumble ? not sure i'd call it that, it is a severe and short dip in rpms that if it would last would kill the engine (it never does).

misfire ? likely not, as a misfire would likely getting more pronounced at high loads/speeds, which never happen.

idling is steady, no dips, no chasing.

[rjahl]

Originally Posted by DaanBMW

imagine you step on the gas pedal to take off. you can imagine that what happens is the rpms go continually up until you feel the engine is revving so high that you should shift to 2nd. so basically the graph would be a continuously rising curve rpm = f(time).

mine would basically be a v. v. brief rpm rise, then a dip - a bog down, feels like a hesitation as it I suddenly took my foot off the gas but I didn't - after which the rpms finally continue the rise expected by the order via the gas pedal. so curve would be a Z shape: up - down - up again.

rumble ? not sure i'd call it that, it is a severe and short dip in rpms that if it would last would kill the engine (it never does).

misfire ? likely not, as a misfire would likely getting more pronounced at high loads/speeds, which never happen.

idling is steady, no dips, no chasing.

If it's a stumble from a stop or low speed right after gunning it I would guess it's the DTC or DSC kicking in.

Mine did the same thing until I changed tires. Dstickland also had the same experience. I thought it was strange to not get lights on the dash.

Even with sticker tires you have to manage your traction / foot or the car will do it for you.

[DaanBMW]

Originally Posted by rjahl

If it's a stumble from a stop or low speed right after gunning it I would guess it's the DTC or DSC kicking in.

Mine did the same thing until I changed tires. Dstickland also had the same experience. I thought it was strange to not get lights on the dash.

Even with sticker tires you have to manage your traction / foot or the car will do it for you.

i actually turn off the 1st stage DSC usually (it screws up the LSD), so no it can't be that. and I'm taking off pretty slow / feathering it when it happens (or I guess it is felt more). it also does it w/ 2 sets of tires+wheels, 18" summers + 17" all weathers

[frenchi]

Originally Posted by DaanBMW

i actually turn off the 1st stage DSC usually (it screws up the LSD), so no it can't be that. and I'm taking off pretty slow / feathering it when it happens (or I guess it is felt more). it also does it w/ 2 sets of tires+wheels, 18" summers + 17" all weathers

Replace your both precat oxygen sensors even if you don't have a Cel you will be surprised

[DaanBMW]

Originally Posted by frenchi

Replace your both precat oxygen sensors even if you don't have a Cel you will be surprised

Can you elaborate on your experience with doing this (symptoms you had fixed) ? As you can imagine after changing lots of parts that were supposed to fix it based all sorts of online threads, I'm a bit leery to try anything without some solid basis.

[whinojosa]

Originally Posted by DaanBMW

imagine you step on the gas pedal to take off. you can imagine that what happens is the rpms go continually up until you feel the engine is revving so high that you should shift to 2nd. so basically the graph would be a continuously rising curve rpm = f(time).

mine would basically be a v. v. brief rpm rise, then a dip - a bog down, feels like a hesitation as it I suddenly took my foot off the gas but I didn't - after which the rpms finally continue the rise expected by the order via the gas pedal. so curve would be a Z shape: up - down - up again.

rumble ? not sure i'd call it that, it is a severe and short dip in rpms that if it would last would kill the engine (it never does).

misfire ? likely not, as a misfire would likely getting more pronounced at high loads/speeds, which never happen.

idling is steady, no dips, no chasing.

Daan,

I'm having a similar experience in my 325i.

I finally received a code as the car went into limp mode. The code indicated a bad CRANKSHAFT POSITION SENSOR. I have the new part in hand and am going to swap out sometime this week.

I'll post back with acceleration hiccup results.

[Taskmaster]

Originally Posted by DaanBMW

imagine you step on the gas pedal to take off. you can imagine that what happens is the rpms go continually up until you feel the engine is revving so high that you should shift to 2nd. so basically the graph would be a continuously rising curve rpm = f(time).

mine would basically be a v. v. brief rpm rise, then a dip - a bog down, feels like a hesitation as it I suddenly took my foot off the gas but I didn't - after which the rpms finally continue the rise expected by the order via the gas pedal. so curve would be a Z shape: up - down - up again.

rumble ? not sure i'd call it that, it is a severe and short dip in rpms that if it would last would kill the engine (it never does).

misfire ? likely not, as a misfire would likely getting more pronounced at high loads/speeds, which never happen.

idling is steady, no dips, no chasing.

Oddly enough, mine is doing this too, and only below 4000rpm.

Changed valvecover, vanos solenoids, sparkplugs, valvetronic sensor, and I have a AIT (but might use my MAF again, and changed the manifold pressure sensor.

I'm a a loss.

[Taskmaster]

Originally Posted by DaanBMW

Can you elaborate on your experience with doing this (symptoms you had fixed) ? As you can imagine after changing lots of parts that were supposed to fix it based all sorts of online threads, I'm a bit leery to try anything without some solid basis.

Let me know what you find.

What else could it be - throttle positioning sensor? Fuel pump? Vacuum leak? O2 sensors?

[Taskmaster]

Fuck, it may be the clutch slipping already. I JUST had it replaced.

[rjahl]

Originally Posted by TheAxiom

Fuck, it may be the clutch slipping already. I JUST had it replaced.

DTC and DSC?

[Taskmaster]

Originally Posted by rjahl

DTC and DSC?

I had the DTC off. I'm at a loss here, I don't know what else I can do.

I'm reading threads and they say its the CDV and I should toss it out....

[rjahl]

Originally Posted by TheAxiom

I had the DTC off. I'm at a loss here, I don't know what else I can do.

I'm reading threads and they say its the CDV and I should toss it out....

Try pulling through a higher gear at slow speed. If it develops good torque and pulls evenly, I would think the problem lies with the DSC.

You can't turn off the DSC completely. The nanny police don't believe you can handle it.

[Taskmaster]

[QUOTE=rjahl;21336031]Try pulling through a higher gear at slow speed. If it develops good torque and pulls evenly, I would think the problem lies with the DSC.

You can't turn off the DSC completely. The nanny police don't believe you can handle it.[/QUOTE}

Basically, it's acting like the clutch is slipping. The Engine speed keeps going while the cars speed accelerates at normal pace. It's odd.

[justpete]

[QUOTE=TheAxiom;21336145]

Originally Posted by rjahl

Try pulling through a higher gear at slow speed. If it develops good torque and pulls evenly, I would think the problem lies with the DSC.

You can't turn off the DSC completely. The nanny police don't believe you can handle it.[/QUOTE}

Basically, it's acting like the clutch is slipping. The Engine speed keeps going while the cars speed accelerates at normal pace. It's odd.

Sounds like they didn't bleed the clutch cylinder.