dgjk

85,000 miles. They said was caused from bad gas and design of direct injection. They recommended using BP gas.

baveagle

85K is pretty good. Got my '08 in July 2010 with 21K and I am at 32K now and started having occasional misfires without CEL. I have only used 93 octane Shell gasoline, but don't know what the original owner put in. I just did a couple of 25 minute "Italian tune-up" runs in 3rd gear and 4,500 RPM that I read about and will do another two runs, before going on a one run per month schedule. This is supposed to fight the the carbon built-up at the intake valves. My HPFP was replaced with the latest design 6 months ago, and injectors were checked and recalibrated on two occasions. Good luck with your "blasted" engine.

ssmokn

"Italian Tune-up". That made me LOL

Don't forget to wear your Ferrari baseball cap while doing the tune-up. It really helps

Chad McCan

I wanted to chime in here. I had this same problem, with the same car. The dealer was clueless. They replaced 3 injectors in it 6 months ago. That's what I decided the problem started.

They put a fuel pump on it 2 months ago. No change.

I realized they were simply experimenting, so I figured I'd experiment on my own, cheap. Replaced the cheapest things first...

All new plugs, no change.

Took it back to the dealer, they wanted to do the walnut blasting, but that wasn't going to fix it. They did replace the low pressure fuel sensor - $400 (what a waste).

I ordered a new coil pack. No change.

I ordered a new injector - Voila! Problem solved.

I'd still like to have the walnut blasting done, but not for $800.

Rez

Can someone please elaborate on the WALNUT BLASTING?

AchtungE60

hahahhaa yea man "sand" blasting. With black walnut powder instead. That's messed up. Use some fuel system conditioner like Lucas and they'll blast themselves LOOL have you seen that blue liquid they use on commercial coffee machines or coffee dispensers once the coffee builds up? pretty much does the same thing....kind how the CLR commercials show. Ever use TARNX on silver. Kind of like that. I love that stuff.

AchtungE60

Injectors? WHY? People, do yourselves a favor and get some BMW Diagnostic Equipment and save yourself some money. I have an E39 in the family that's running on 300K miles and there are no injector problems. Seen 3 Ford F-150's running close to the same. TAKE CARE OF YOUR VEHICLES! period. you do not need to use premium all the time but try to use it every 3rd fill and at least once every 3 months run some good fuel system conditioner (always on the highest octane) ... I have 3 bimmers over 100K miles which are parked at my house and i personally alternate driving and have no issues with any injectors. If you have the proper equipment you dont have to play the guessing game. You'll KNOW what is failing and tackle it the first time.

Not saying the problem couldn't be an injector but 'guessing' isn't going to help. By the time you're done guessing your pocket will be empty. Trust me.

Rez

THANK YOU, AchtungE60.

NYAWE60

I'm speaking from experience here. My car was running a bit shoddy at 43K, the dealer replaced two injectors. Problem solved that time.

Afterwards I installed the COBB AP and the tune naturally requires that all components be running in tip top shape. At 51K I started getting misfires. The Cobb AP diagnostics tool determined it to be a misfire on cylinder 3. I took the opportunity to replace all of the spark plugs at this point. To say they were shot would be an understatement. The gaps were all off and physically they were just beyond finished. Since it mentioned cylinder 3, I also replaced that coil, at $40/coil I decided to do it "just in case". Problem solved after that, car runs 100% and is a total fire breathing animal with 400 hp and 400+ lb/ft torque.

As for any twin turbo BMW, I couldnt see why you would use any fuel with less than 91 octane. The motor is designed with a specific air fuel ratio mixture in mind. Running less than 91 would lean out the fuel mixture, NOT GOOD on a turbo motor. I mean in the end it's a $60K car, if people have issues spending $1.50 - $3 more to fill their tank with premium this car may not have been the best choice.

NYAWE60

The N54 is a much much different motor from the N52/other non turbo BMW motors. It has been shown that the fuel treatments like Lucas DON'T WORK. The carbon build up is extremely stubborn and does require being cleaned with the head open. Do some homework on people that have had the cleaning service done. $500 is very cheap, I'd pull the trigger if I ever had that offer, most dealers charge $800+. You could clean it yourself, some guys have done it with standard gun cleaning tools, but chances are they're mechanically inclined and comfortable opening up the motor.