[MK335i]

Already replaced plugs and coils about 2-3K miles ago. Went through my own diagnostics procedure and swapped coils around to see if problem followed and it stayed on cylinder 5. I don't think the car has ever had injectors replaced so I am thinking it may be one of those.

My car is an 09 E90 N54 build and was wondering if there are any recalls or notifications from BMWNA regarding replacement. My car has no warranty given it has 63K on the clock.

[Jeff@TopGearSolutions]

Pull spark plug 5 and see if it's fouled with fuel. If you a have a rough start up when the car is cold in the morning it's usually injector related.

[BQTuning]

Injector

[924er]

Pull the plug out when it's cold and smell for fuel. It won't rule out injectors completely but it's a good start.

I had a misfire due to a faulty injector but normal crank time.

What's the last 2 digits of the injectors? I think -12 is the current.

[MK335i]

Originally Posted by 924er

Pull the plug out when it's cold and smell for fuel. It won't rule out injectors completely but it's a good start.

I had a misfire due to a faulty injector but normal crank time.

What's the last 2 digits of the injectors? I think -12 is the current.

Car cranks fine every morning on start. I don't have the tool available to pull my plug.

I can drive around town and on the interstate just fine (minor jolts and bumps for the misfire) unless I really hit the gas and that's when it shutters like crazy.

Also, it doesn't throw a code or the SES light unless I floor it.

[Aashenfox]

I just had 5 out of 6 injectors replaced due to recall yesterday. Of course I'm in Europe and things are a bit different over here (we don't have any options on the HPFP like you guys do), so I don't know if the same recall will be valid for you, but my car is an 08 with 35k miles well out of warranty. They did it completely on their own, I didn't even know until they called me to tell me it was ready and said they also changed all but one of the injectors (although I am fairly confident one of them was leaking)...I was happy to say the least, as I also didn't have to pay for the spark plug install I had asked for (since they had to come out for the injectors).

[924er]

Originally Posted by MK335i

Car cranks fine every morning on start. I don't have the tool available to pull my plug.

I can drive around town and on the interstate just fine (minor jolts and bumps for the misfire) unless I really hit the gas and that's when it shutters like crazy.

Also, it doesn't throw a code or the SES light unless I floor it.

Bro that's a common misfire and if u don't have the tool there would be no way to determine if your plug is bad. I know u said u changed it 3k miles ago but it could still be bad trust me

Get the tool. Swap plug if coil and see if it follows. Then move on to injectors.

It sounds to me like a plug.

[proTUNING Freaks]

Unless you have cold start issues in the morning it is highly unlikely its an injector issue. If after plugs and coils you're still misfiring you can try replacing the injector in that cylinder blindly (make sure you get it recoded too). If you're lucky it'll be resolved. Otherwise next thing I'd do is do a compression and leak down tests. All of this applies if you're a 6AT car. For manuals there is another cause to them and it relates to the OEM dual mass flywheel which with time can start to vibrate and cause false misfires. The fix there is to swap it either for another OEM dual mass flywheel (if the car is below 500wtq levels) or go with a single mass flywheel. This doesn't apply to automatics obviously.

[MK335i]

Originally Posted by proTUNING Freaks

Unless you have cold start issues in the morning it is highly unlikely its an injector issue. If after plugs and coils you're still misfiring you can try replacing the injector in that cylinder blindly (make sure you get it recoded too). If you're lucky it'll be resolved. Otherwise next thing I'd do is do a compression and leak down tests. All of this applies if you're a 6AT car. For manuals there is another cause to them and it relates to the OEM dual mass flywheel which with time can start to vibrate and cause false misfires. The fix there is to swap it either for another OEM dual mass flywheel (if the car is below 500wtq levels) or go with a single mass flywheel. This doesn't apply to automatics obviously.

Nope, zero starting issues and yes 6AT. I'm wondering if it is cyl 5 plug though because I have swapped coils and problem did not follow. Feels the same when I had this problem previously before my new plugs.

[Jeff@TopGearSolutions]

I'd suggest getting the tool and pulling the plug. We are blindly guessing here, unfortunately.

The answer is in the plug.

[proTUNING Freaks]

Originally Posted by MK335i

Nope, zero starting issues and yes 6AT. I'm wondering if it is cyl 5 plug though because I have swapped coils and problem did not follow. Feels the same when I had this problem previously before my new plugs.

I thought you had the plugs replaced. What plugs are you running currently?

[MK335i]

Originally Posted by proTUNING Freaks

I thought you had the plugs replaced. What plugs are you running currently?

I did have plugs replaced by a dealer here in Ky but this was prior to me learning how to DIY on this type of stuff. I am running the bosch plugs that I ordered from ECS or another website making me think even more now it could be a faulty plug.

[gabylonfive]

just out of curiosity, are you tuned?

[MK335i]

Originally Posted by gabylonfive

just out of curiosity, are you tuned?

Yes was tuned - just Cobb stage 1 aggressive - I uninstalled it to see if that helped make a difference but no change.

[MK335i]

Originally Posted by 924er

Bro that's a common misfire and if u don't have the tool there would be no way to determine if your plug is bad. I know u said u changed it 3k miles ago but it could still be bad trust me

Get the tool. Swap plug if coil and see if it follows. Then move on to injectors.

It sounds to me like a plug.

Now I am baffled, yesterday I threw a bottle of STP in the tank and now today she is running almost normal with a few jolts on throttle but not the strong shaking or jolting as before. Still a few stumbles on idle but nothing like before when the car felt like she was going to die or blow up.

I am wondering if it is purely carbon buildup on my intake valves. I have never had it blasted nor do I even know if that has anything to do with the throttle jolts.

[924er]

Originally Posted by MK335i

Now I am baffled, yesterday I threw a bottle of STP in the tank and now today she is running almost normal with a few jolts on throttle but not the strong shaking or jolting as before. Still a few stumbles on idle but nothing like before when the car felt like she was going to die or blow up.

I am wondering if it is purely carbon buildup on my intake valves. I have never had it blasted nor do I even know if that has anything to do with the throttle jolts.

You'll be more baffled when that misfire comes back. These cars misfire man. Most of the time it's plugs and coils but can also be the injector.

I never heard of someone curing a misfire like you but enjoy it I guess

[MK335i]

Originally Posted by 924er

You'll be more baffled when that misfire comes back. These cars misfire man. Most of the time it's plugs and coils but can also be the injector.

I never heard of someone curing a misfire like you but enjoy it I guess

Ha - yup it came back man. But now its gone again this morning so I am going to swap out my plug on cyl 5 this weekend. If that doesn't work I will take her in.

I did notice one of the codes I got it to throw yesterday was a low fuel misfire or something to that extent but I did not have low fuel.... hmmm

[Jeff@TopGearSolutions]

Originally Posted by MK335i

Ha - yup it came back man. But now its gone again this morning so I am going to swap out my plug on cyl 5 this weekend. If that doesn't work I will take her in.

I did notice one of the codes I got it to throw yesterday was a low fuel misfire or something to that extent but I did not have low fuel.... hmmm

If you take a look at the Misfire Guide Thread, you'll notice that misfires are mostly attributed to spark plugs, coil packs and/or injectors.

However it's not limited to those only, it can sometimes be gunked up intake valves, dirty/failing vanos solenoids.

Last but not least it can sometimes be related to the low or high pressure fuel pumps.

http://www.e90post.com/forums/showthread.php?t=631829

Intake valves should be cleaned every 35K miles.

Vanos solenoid problems sometimes may throw a code as well as the potentially failing fuel pumps.

How many miles are on the vehicle and are there any other codes? Those codes could be a big hint.

[MK335i]

Originally Posted by Jeff@TopGearSolutions

If you take a look at the Misfire Guide Thread, you'll notice that misfires are mostly attributed to spark plugs, coil packs and/or injectors.

However it's not limited to those only, it can sometimes be gunked up intake valves, dirty/failing vanos solenoids.

Last but not least it can sometimes be related to the low or high pressure fuel pumps.

http://www.e90post.com/forums/showthread.php?t=631829

Intake valves should be cleaned every 35K miles.

Vanos solenoid problems sometimes may throw a code as well as the potentially failing fuel pumps.

How many miles are on the vehicle and are there any other codes? Those codes could be a big hint.

Only codes are the Cylinder 5 misfire ones.

63000 miles on the car.

[Jeff@TopGearSolutions]

Originally Posted by MK335i

Only codes are the Cylinder 5 misfire ones.

63000 miles on the car.

If you can get the specific code numbers that would help. You mentioned above something about fuel which is why those codes are important.

Once you resolve this, assuming it's not your intake valves gunked up, you should get those cleaned anyway. You'll likely gain gobs of throttle response, gas mileage and 10+HP. At the mileage you have they should have been cleaned almost twice now.

[924er]

Originally Posted by MK335i

Ha - yup it came back man. But now its gone again this morning so I am going to swap out my plug on cyl 5 this weekend. If that doesn't work I will take her in.

I did notice one of the codes I got it to throw yesterday was a low fuel misfire or something to that extent but I did not have low fuel.... hmmm

My money is on a bad plug. If I'm right u gonna PayPal me $20

[MK335i]

Originally Posted by 924er

My money is on a bad plug. If I'm right u gonna PayPal me $20

Haha I hope you are right.