ADD

Started a couple days ago.

When driving underway, (e.g. not much on the gas, up to speed on the expressway), I get a strange irractic pulsing sensation. Not any logic or pattern to it. It almost feels like point where you may stall an engine with a manual tranny where the engine starts to lurch forward, but I'm cruising.

I have been trying to pinpoint it throughout the day, and can't. I can't tell if it's the non-oem wheels I have on for winter, snow packed in the wheels throwing off the balance, clutch, tranny, engine.

Strange.

Under load, (semi full throttle, rowing through the gears), no problems or sensations like that.

I was even thinking maybe it's something to do with the drive by wire throttle. I have swapped for the oem alum. pedal kit. Being that it only appears when light on the pedal.

I have noticed over the months of driving this new car, that periodically at start up, I'll pull away in first gear just getting underway, I'll be clicking my seat belt or something, and clutch fully disengaged, in first gear, steady on the accelerator, the car starts to lunge for a couple seconds, and then when I push the accelerator down to get going, it smooths out. Only happens on the first start from cold. Maybe that has something to do with the above issue.

Any ideas before I take it to the dealer? (I have 4,300 miles till an oil change.) About a month and a half.

TIA

MiamiPhill

Sounds like the beginning of the end of your fuel pump. Someone will post the related threads.

MiamiPhill

http://forums.e60.net/index.php?showtopic=...mp;#entry761131 here is one.

ADD

Good ideas, but I don't have the same symptoms...

Long to crank from cold start
No

loss of power at speed
Only under light load, not a full throttle

Horrid engine vibration between 1500rbm-3000rpm
No

Exhaust sounds like Garbage truck or Ricer fart can
No

Possible Limp home mode ( mine did not have this come up)
No

Never a check engine light.

Any other ideas?

ObD

Try a different brand of gas.

ADD

I got to thinking that as I read through the posts on this and other forums last night regarding the HPFP and ethanol-blamed problems in the 335s and now 535s. Any of the N54 engines.

It is interesting that for the past five or so gas tanks, I've been getting gas at the same Mobil station in town because they had the best price for premium. (Maybe you get what you pay for) Last night I didn't feel like driving to that station, so I got gas at a Hess. Always premium. It will be interesting to see if anything changes.

We don't have ANY of the "top tier" stations around us, or even in Upstate NY I don't think, unless it's branded under a different name.

Anybody know if any of THESE stations are included in the top tier list, (as a sub brand of one listed)?

Mobil
Sunoco
Hess
Kwik Fill (Sounds like Kwik Star, but couldn't find an association) Although Kwik Fill appears like a discount station, I have had very good luck with thier gas in my old e39.
Citgo

TIA

bigbadbull

It is the High Pressure Fuel Pump Failure.... Hands down. If you BMW dealer tells you other wise take to car to another dealer. It will show up as low Fuel pressure on one or two ( usually #2 ,3, or 6 for some reason) of the cylinders...
Cold weather and Ethanol content "Above" 10% are BMW's reasons for the issues...

Go log it in with the Nhtsa to get BMW to get serious about them, it is almost a Joke now with the N54. I'm on replacement #2 and some of the E90's have gone threw 4-6 of them in under 60K.
http://www-odi.nhtsa.dot.gov/ivoq/

C's Bimmer

I get this too, but not when I'm driving.

ADD

I wanted to dig this out and throw another idea out there.

As I don't have many of the stated problems with the HPFP issue, I've been trying to diagnose some other problems.

I did put some Techron Fuel System Cleaner in, and we'll see what that does.


Is it possible that the throttle linkage on the accelerator or drive-by-wire system is having a problem?

I swapped out for the OEM BMW SS pedals and full accelerator swap. (P&P)

Could the plunger have an issue, what about snow/moisture getting in there? I wouldn't think so, but just throwing out other ideas.

Anybody experience?

HotLap

ADD - thanks for the PM and you are correct I do have the 535 with the SprintBooster installed. I haven't had any issues with the SB at all and have not had the kinds of symptoms you are describing either. I do however have the extreme cranking to start - especially at cold start and have been meaning to get it to a BMW dealer for diagnosis. I wish I couold be more help - but no issues with the SB whatsoever