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Art k
06-25-2012, 05:25 AM
I have a 2008 550i, and it seem like sometimes when I step on the gas it hesitates, has anyone else had this problem?

BickUW89
06-25-2012, 08:19 AM
How many miles on the engine?

First two remedies to consider:
1) Clean the MAF
2) Replace the spark plugs

luxcar
06-25-2012, 08:27 AM
My car used to do it after regularly driving it in stop and go traffic. BMW shop foreman told me that it is due to transmission program in D mode. They updated the software and asked me to drive in Sport mode in stop and go traffic. It worked for me.

Now I drive in sport mode and don't have the problem.

Art k
06-25-2012, 08:52 AM
ok cool, i'll have to try that

jsimon7777
06-25-2012, 09:40 AM
I'm sure I could search it up, but what plugs and MAF cleaner work best?

Art k
06-25-2012, 10:27 AM
what is the MAF?

BickUW89
06-25-2012, 10:51 AM
I'm sure I could search it up, but what plugs and MAF cleaner work best?

Here's what I use:
330430

It's just Hexane, so any similar product will do the job.

BickUW89
06-25-2012, 10:55 AM
what is the MAF?

Search is your friend, but since you're a noob I'll do this one:

MAF = Mass Air Flow. It's a small filament in the air intake just after the air filter that helps the engine's computer calculate proper fuel/air mixture. Over time oils and micro particles can accrete, which affects the filament's resistance, and thus the signal that is sent to the computer. All you have to do is shoot a couple squirts of hexane onto the filament to clean it off. DON'T TOUCH THE FILAMENT - it's fragile. Just spray it with the cleaner and put everything back together. Takes 5 minutes.

This made a huge difference on my E60 at around 55,000. YMMV.

Art k
06-25-2012, 04:32 PM
Noob huh, r u trying to call me a newbie? Or making fun?

BickUW89
06-25-2012, 04:47 PM
Noob huh, r u trying to call me a newbie? Or making fun?

Newbie to the site. Not a slam. Just want to get you calibrated to the culture around here. Lots of helpful folks, but it's recommended that you search first, then ask.

Art k
06-26-2012, 05:16 AM
Cool, so I see u have a 535 and 550, which one do U like more?

BickUW89
06-26-2012, 08:30 AM
Cool, so I see u have a 535 and 550, which one do U like more?

See my sig: E39 < E60 > F10

E60 550 me likey better than F10 535

Art k
06-27-2012, 04:33 PM
On ur 550, when u r cruising at about 40 and step on it to pass it takes a bit for it to get speed?

luxcar
06-27-2012, 06:48 PM
On ur 550, when u r cruising at about 40 and step on it to pass it takes a bit for it to get speed?

Sometimes my car also takes a bit to pass in D mode. I had test driven a 2007 550i also and it behaved the same in D. The transmission is learning your driving habits. To change the behavior (in D) you have to be heavy on pedal and it will start responding better.

That is why I drive it in Sport mode all the time except for freeway cruising. It behaves like a totally different car in sport mode.

BickUW89
06-27-2012, 07:00 PM
On ur 550, when u r cruising at about 40 and step on it to pass it takes a bit for it to get speed?

Yeah, there's a bit of a hesitation, but that's mostly because the car is usually not in the power band's sweet spot at that speed. RPMs are probably loping down around 1,200 to 1,500 at 40mph. In those situations, I paddle-shift down a couple gears, or I'm already in Sport mode which completely eliminates throttle lag. I pretty much always drive in Sport mode, except on the freeways (Sport takes away overdrive/6th gear).

Art k
06-27-2012, 08:22 PM
Cool I'll try driving in sport mode, so will cleaning the MAF help it any? The car has 41000 miles

BickUW89
06-27-2012, 09:53 PM
Cool I'll try driving in sport mode, so will cleaning the MAF help it any? The car has 41000 miles

Who knows? Only way to tell is to do it. Cleaning it has only positive outcomes; you can't hurt anything by doing so, and it's a cheap and easy maintenance item. get on it, son!

Kalil147
06-28-2012, 12:31 PM
Has anyone tried the Sprint Booster? On my 545i I cleaned out the MAF sensor, removed carbon filter, installed K&N, and installed iridiums. It helped a lot. 70k miles.

Space grau 550i
06-28-2012, 03:14 PM
Has anyone tried the Sprint Booster? On my 545i I cleaned out the MAF sensor, removed carbon filter, installed K&N, and installed iridiums. It helped a lot. 70k miles.

Nope, have not tried the Sprint Booster, but was thinking about it. You will find guys on here that are running the Sprint Booster and swear buy it. You will also find guys on here that will say it's a placebo affect, just plant your foot harder.

Kalil147
06-28-2012, 05:41 PM
That is right. Id rather not risk the $300 either.