Troubleshooting - Distinguishing between a COIL PACK and INJECTOR issue - N54

[Codes2]

Hello all,
All insights are appreciated.
I bought my 2008 335xi a couple months ago.
It has new plugs, but only 2 new coil packs at this time. (the others are original 2008)

A lot of the 'kicking' (instantaneous and short drop in power) that it had was addressed with a couple coil packs and VANOS solenoids.

There is still some kicking when at essentially full throttle (or close to).

I'm swapping my Coil Packs around in the hopes to track a change in ECL cylinder identification, though it's only thrown a code and required a restart once... usually the symptoms are so brief it doesn't throw a code... and to be honest, I let off the gas out of instinct, as I don't want to over push it until it's running smooth.
The swapping may show something... if/when I get another code.

However, I believe I must entertain the idea that this could be the injectors (or an injector) as well. (N54 seems to have a history here)
I'm entirely unsure how the different fault would manifest in symptom.
Would it be identical? Or are injector failures/dying fairly different than the feel of a Coil Pack missing a spark?

Many thanks!!

[RocketSurgeon]

You're on the right track moving around the coils. A misfire is a misfire, you won't feel a difference between injector/coil/plug. Do you know what index your injectors are? Anything under index 11 is problematic. Have your valves been walnut blasted recently? Injectors are expensive, but if you get the 13538648937 injector, it's half the price of the 13538616079. Same part, different price. You can sometimes spot a bad injector by removing it and looking for a carbon covered tip, but that requires replacing the injector seal (13537584315), which requires special tools.
A few tips on injectors. They need to be coded to the car (you can diy with $20 cable). Be sure to use new decoupling elements on each injector, or very bad things will happen. If you remove an injector or install a used one, be sure to install new injector seals, or you will damage the head in short order. If you use injectors of index 11 or higher, you must replace the entire bank of 3 at the same time.
Lots of guys have chased misfires for ages before getting a walnut blast or upgrading to index 12 injectors. It can be tricky to definitively nail down the cause of misfires.

BTW, what codes are you getting? I see that you swapped VANOS solenoids, were you getting a code? It really helps to have BMW code reading software, as the manufacturer codes show far more information than generic P-codes. If you get the $20 K+DCAN cable, you can do 90% of what the dealer can.

[White94RX]

Running rough on a cold start and then it smooths out is usually an injector. It may have leaked down while parked and takes a few seconds to get primed with fuel.

A miss while driving or under a load is usually a coil from my experience.

A dead cylinder under any condition is usually a coil, but is very easily diagnosed because it will set a code for sure.

[Codes2]

Thanks for the responses.
I sincerely appreciate the info and dialog.


On the above reported incident, these were the OBDII reader codes: P0305 (Cylinder 5 Misfire), P0306 (Cylinder 6 Misfire) and P0300 (Random Misfire)
Is this as close as an OBDII reader gets to identifying the actual fault (rather than symptom)? As in, it is or is not going to say "Injector 5" or "Coil Pack 5"?

While it can run a little rough on start, it's not kicking like it does under heavy load.
I'm moving the Coil Packs on Saturday, so we'll see if the codes reflect a follow or stay with Cyl 5& 6.

RocketSurgeon
- I'm not sure on the Injectors index number. I just googled. My guess is it's the top-right 2 digit number, in which case mine are either 4 or 9. (my picture is too blurry)
- No walnut blasting. I'm trying to find somewhere other than dealer in Southern Ontario Canada. (I'll have done asap)
- My Injector number doesn't match either you mentioned. I'm pretty sure they are original as the dealer doesn't have anything on them being replaced. My number is closer to (too blurry for exact) 135375_5261-0_ (with underscore being unable to read today).
- Based on what White94RX was stating above, my Injectors are likely on their way out. I'll keep an eye on the startup shakes. Reading some of your other posts (and this one) I've learned to at least do them in banks, due to the different Index number. Thanks. (code it, etc)
- VANOS solenoids were swapped by BMW dealer. Truth is, the severe symptom I would get at WOT was possibly due to a collapsed oil filter, which was not found until after doing the VANOS solenoids. The little used car dealer I bought the car from brought it to BMW when the issue occurred (the day I bought the car). The used car dealer paid for the VANOS solenoids, so good for me. Likely too bad the collapsed oil filter wasn't found first...

---

I wish to buy this K+DCAN cable and any software to help my troubleshooting.
I've been reading up on this, but my confidence in what to buy is not quite there yet. (or what else might be required)

If you happen to know links to the required, I'd be happy to use them... I respect that's a little lazy as I'm sure I'll run into something I'm confident in on this forum in time.

[Codes2]

I edited my last post for cleanliness, but then it didn't get bumped.
So, I'm adding this post, but just read the one above

[RocketSurgeon]

Thanks for the responses.
I sincerely appreciate the info and dialog.

On the above reported incident, these were the OBDII reader codes: P0305 (Cylinder 5 Misfire), P0306 (Cylinder 6 Misfire) and P0300 (Random Misfire)
Is this as close as an OBDII reader gets to identifying the actual fault (rather than symptom)? As in, it is or is not going to say "Injector 5" or "Coil Pack 5"?

While it can run a little rough on start, it's not kicking like it does under heavy load.
I'm moving the Coil Packs on Saturday, so we'll see if the codes reflect a follow or stay with Cyl 5& 6.

RocketSurgeon
- I'm not sure on the Injectors index number. I just googled. My guess is it's the top-right 2 digit number, in which case mine are either 4 or 9. (my picture is too blurry)
- No walnut blasting. I'm trying to find somewhere other than dealer in Southern Ontario Canada. (I'll have done asap)
- My Injector number doesn't match either you mentioned. I'm pretty sure they are original as the dealer doesn't have anything on them being replaced. My number is closer to (too blurry for exact) 135375_5261-0_ (with underscore being unable to read today).
- Based on what White94RX was stating above, my Injectors are likely on their way out. I'll keep an eye on the startup shakes. Reading some of your other posts (and this one) I've learned to at least do them in banks, due to the different Index number. Thanks. (code it, etc)
- VANOS solenoids were swapped by BMW dealer. Truth is, the severe symptom I would get at WOT was possibly due to a collapsed oil filter, which was not found until after doing the VANOS solenoids. The little used car dealer I bought the car from brought it to BMW when the issue occurred (the day I bought the car). The used car dealer paid for the VANOS solenoids, so good for me. Likely too bad the collapsed oil filter wasn't found first...

---

I wish to buy this K+DCAN cable and any software to help my troubleshooting.
I've been reading up on this, but my confidence in what to buy is not quite there yet. (or what else might be required)

If you happen to know links to the required, I'd be happy to use them... I respect that's a little lazy as I'm sure I'll run into something I'm confident in on this forum in time.

The generic codes won't get super specific like the BMW specific codes. There are codes for a bad injector, I've had one before (cylinders 5+6 coincidentally). The injectors or coils generally fail in a way that does not generate a specific code though.
Unless your injectors have been done along the way, they will be some early index.
The index number is in the upper right, after the dash.
The collapsed oil filter isn't great. I'd be sure to use Mann filters and short oil change intervals for a while.
As far as cables go, you'll want one with a green circuit board and a switch. You can get a good one for under $20 on ebay or aliexpress. I'll PM you download links for the software.

[Codes2]

Thanks RS.
I'll download tonight.
Will also start searching out that cable.

I moved my coil packs this morning.
Ironic that there is no little kicks... now that I'm ready for them.
I know they'll start in a day or 3 and get worse.

Injectors are Index 9,9,9,6,9,6 (cyl 1-6).
Would this dictate that 4 of 6 were changed? Or could they come new and mixed (pre index 11)?

[RocketSurgeon]

Thanks RS.
I'll download tonight.
Will also start searching out that cable.

I moved my coil packs this morning.
Ironic that there is no little kicks... now that I'm ready for them.
I know they'll start in a day or 3 and get worse.

Injectors are Index 9,9,9,6,9,6 (cyl 1-6).
Would this dictate that 4 of 6 were changed? Or could they come new and mixed (pre index 11)?

It looks like 4 of the 6 have been changed, probably 2011ish. Interestingly they had a service bulletin where certain index 6-8 injectors would be tested and replaced as needed by the dealership. My 2009 came with index 7s, but 3 of them had been replaced by index 9s under warranty. They would only replace those that failed the test, but if 4 out of 6 failed, why not replace them all?
I bought a set of 8 nearly new index 12s out of a wrecked X5m for $200 and replaced all mine

[Codes2]

Thanks RS.
Good know probable reason for the 4 being updated... presumably the original 2 will give symptoms first.

We're they (XM5) the same model as 335 or just equivalent spec?
Wondering if it's a common part through models.
(I don't see models in your signature... or at least not come phone)

[RocketSurgeon]

Thanks RS.
Good know probable reason for the 4 being updated... presumably the original 2 will give symptoms first.

We're they (XM5) the same model as 335 or just equivalent spec?
Wondering if it's a common part through models.
(I don't see models in your signature... or at least not come phone)

The same injectors are used in the N54, N63, and S63, same part number and everything. I think the N74 V12 engine uses them too, but that's very rare.
That obscure half price injector mentioned above is even the same exact part offered at half price for S63 recall work.
My car is a 2009 335i coupe.

[Codes2]

Hi all, looking for some quick advise...

So, the symptom followed one of the Coil Packs in the move from Cyl 5 and 6 to 3 and 4.
I hit WOT coming onto the highway, then the shudder and loss of Cyl 3.
After pulling over, shutting the car off, turning it back on, the symptom remains.

My car has x4 Bosch and x2 Delphi.
The Bosch are original, and fit snug on the plug.
The Delphi cover-boot does not quite sit snug on the Coil Pack hole. I spent about 30 minutes looking at them the other weekend. I'm guessing they could let dirt/moisture in due to the poor boot cover seal, but at this time it's all clean inside.

Now the question is, do I buy a 3rd manufacturer (BWD, Advance-Tech, Echlin, Eldor) for this single replacement?
Or rather, do I order 4 or 6 Bosch and wait for shipping, while hitching a ride w/ colleagues.

I understand there is some personality with replacing Injectors (bank/index).
I'm not sure if this is true to any level with Ignition Coils.

--- --- ---

P.S. I drove my car the few KM to work without Cyl 3 firing. I'm wondering if that means I've flooded my CAT with unburned fuel, hurt the turbos or if the car is smart enough to cut fuel to the Cyl. I though of the CAT at the time, but not the turbos...
> Was this a particularly bad choice?

[Codes2]

I've got a set of 4 Bosch on the way.
Expecting to install tomorrow evening.

I'm leaving the 2 newer Delphi installed, unless anyone speaks out against the mixing, or the poor boot sealing they have.

I may post my question about driving 10 KM with Cyl 3 not firing... and possible damage... to it's own thread if no response here.


Thanks all!
Looking forward to solid ignition coils!

[Codes2]

Thanks RS.

I sent a PM, however my Sent Box says "0", so sending from here. (maybe it's delayed as I've not messaged out before?)

I'm looking to buy the K+DCAN cable from Amazon.
Naturally, I see a few.
You mentioned a green circuit board and a switch above.
I see many with a clear hood and a PCB.
I can't distinguish one PCB from another, so imagining as long as I see a green PCB it's good?

I haven't yet seen any with a switch.
Is this to perform the equiv of unplugging and plugging back into the OBD2 port?

Many thanks!

[Codes2]

Cable Ordered (w/ Switch). Excited to receive. Should arrive early Oct.

For those following this specific thread - the new Ignition Coils did the trick. So smooth, no glitches at all.

[RocketSurgeon]

Delphi coils are generally very solid. On the newer cars, the SIB specifically instructs techs to replace the problematic bosch coils with Delphi. Bosch are pretty solid for the n54 though.
As far as the cylinder 3 cutout mentioned earlier, the car cuts fuel on non-firing cylinders to prevent damage.
I might actually buy a spare coil for my tool kit now, coil problems are fairly common.
I can't remember if I sent you links, PM me if you need them

[Codes2]

Hey RocketSurgion,

I did get you link. Much appreciated.
Input like yours totally flips the experience of owning one of these babies.

I can't say just how much driving makes me smile.
I've had a dozen + cars. Each unique... Saab, lifted Jeep, 4 bimmers... this kitten found my buttons.

She's got personality... but you can't love something without it.