[berthagator]

Hi, have a 07 E90 with 102k on it - recently started misfiring, especially going uphill with moderate acceleration. Twice during heavy acceleration has gone into limp mode, first time turning the car off and back on cleared the SES light, second time did not.

Took to dealership to see if HPFP was failing again (first one replaced 4/13). They said it isn't the HPFP, but instead, said spark plugs need replacing (no big deal), oxygen sensors need replacing, and intake valve should be cleaned. Altogether, quoted price of $2500.

Took to independent mechanic who has been highly recommended and specializes in BMW, who confirms spark plug replacement, but then says all 6 fuel injectors should be replaced - cost close to $3000!

Checking now to see if the injectors match the part numbers covered by the recall - production date for car is 8/2007, so matches the range in SI B13 14 10, but no recalls show on the BMW site.

Help? We have no idea what to do now - if the injectors match the range for the recall, do we go back to BMW and try to insist on replacement? But then, why wouldn't the dealer tell us the injectors are failing?

[CHECKERED]

just replace plugs first, and go from there

if you are worried about the injectors, post the part number anything that ends with -08 or above (09,10,11,12) are all good
06 or below were recalled

[Mike@N54Tuning.com]

Start with changing the spark plugs. Pretty simple to do even on your own..

Mike

[berthagator]

Help me out - I have programmer brain - would just replacing the spark plugs correct the problem? I'm just trying to understand whether replacing the plugs will rule anything in or out.....thank you in advance for your responses - I really appreciate your expertise!

[albotronic]

Originally Posted by berthagator

Help me out - I have programmer brain - would just replacing the spark plugs correct the problem? I'm just trying to understand whether replacing the plugs will rule anything in or out.....thank you in advance for your responses - I really appreciate your expertise!

There is a chance it will. Typically spark-plugs, coils or injectors are responsible for misfires. There are other components too but the above should be checked first. Any one of the above components may cause a misfire or it could be a compound problem ie. bad injector ruining your spark-plugs. Spark-plugs are the cheapest to replace - so might as well do. Post pics after and maybe someone can chime in to see if there is irregular wear - which would indicate the spray pattern on an injector is off. Keep them in order if you are going to post pics.

Best,

Al

[Milan]

I had a similar problem to you before with my car, what ended up making it run right was replacing the VANOS solenoids.

I have replaced: spark plugs, coils, injectors, boost control solenoids, and now VANOS solenoids (in that order).

Start with plugs but more likely than not be ready for any of those to fail at any point in time if you are unaware of their history

[berthagator]

So our indy guy replaced the plugs, and "re-indexed the injectors", and says it's running fine now. Wasn't throwing any O2 codes, but then, the dealer had cleared those codes for some reason. I'm pretty darn confused now, but getting out for about $800 as opposed to $3000 makes me happy.....will be interesting to see how long it lasts.

I've never encountered such a confusing car to troubleshoot.....

[Jeff@TopGearSolutions]

No doubt it is confusing but there is plethora of information available here and all the issues you have are common on this platform.

Spark plugs were necessary for sure. Spark plugs are a common failure point as the gap increases because of wear the car starts to misfire.

If there is one thing this car likes it's proactive maintenance.

You should consider having your intake valves cleaned every 35,000 miles. If you've never done it before you are probably being robbed of over 20HP or more.

It will also improve your gas mileage, idle and start up. Feel free to shop around with some independent shops. Prices range from $300-800 so it's well worth shopping around.

Injectors have always been an issue on these cars. The latest revision I believe ends in "-12".

Last but not least is vanos solenoids. They need proper upkeep. You can clean the vanos solenoids or replace, depending on your budget.