[Angel 5]

Hello,

I need a little help with my 2008 BMW E93 328i US-Spec with a little over 160.000 km. 5 or 4 days ago I had a misfire on cylinder 2. I went to my local shop and they replaced ignition coil and spark plug on that cylinder. The error was erased and did not reappeared, but the engine still had a rough idle.

Yesterday I rechecked and the misfire on cylinder 2 is back. This is the exact error from my Carly: "Misfire detection cylinder 2 in 4 Firing order Code: 0029CE".

Today I did a short clip:

And a screenshot from Carly with some injectors parameters.

Any help is appreciated.

[Angel 5]

And the attached one.
And the freeze frame:
Faultcode: Misfire detection cylinder 2 in 4 Firing order
Faultset 1:
(appeared at: 160360.0km)
Load value for misfire detection:
15.23 %
engine temperature:
97.50 °C
No-load value for misfire detection:
6.64 %
Voltage accelerator sensor 1 monitoring:
0.70 V

Hope this helps.

[JuniorB]

There is another post with someone having a consisant misfire on 6, and goes away when you pull another sensor plug off. Really weird that this is the second case with misfires on the early n52.

[Angel 5]

Can you add the link here, I am not able to find that thread... Thanks .

[JuniorB]

It may be over at 5 series net. Look for number 6 misfire on 06 n52

[Angel 5]

And the plot thickens...

Today we did a swap of injectors. We replaced the injector from the 2nd cylinder with the one from the 1st cylinder but the error remains on the 2nd cylinder. Also, when checking the spark plug from cylinder 2, I saw that it was smoked but dry.

Any ideas on what to check next?

[Angel 5]

Hello,

After a long long long period of time (the car was sitting for two months) I finally managed to bring the car to a shop. It stayed there for three weeks, no one knows exactly what was the issue, the car runs fine (at least for now) but I have a new "issue". The fuel economy is sky high. In city traffic, before all of these, I had something like 12 to 15 l/100km and now I have something around 25 l/100km. Which is... a lot!


Now, I want to list what we have done to the car:
- We replaced a broken air intake valve (correct me if I'm wrong, see below);
- The cylinder head was honed;
- Camshafts have been checked, they told me that there is no issue here;
- New cam followers (I think this is the correct name in English );
- New timing chain and timing set;
- New oil (Liqui Moly Top Tec 4200 5W-30);
- New gaskets, bolts, etc.
Hopefully I didn't missed anything. Spark plugs and coils are not replaced.

Any ideas of what might have caused the huge increase in fuel economy?

[W37V]

Bad fuel economy is possibly bad Eccentric shaft sensor? Are you able to rev to your redline? was bad fuel economy after timing chain replacement? Maybe your timing is off.

Also, misfire could be from bad coil connection. Newer bosh coils tend not to provide quite the best coupling, so make sure that the wires are pushed all the way into the coils. Misfire could also be bad spark plugs. Swap them and see if it still persists. That should've been your 1st thing to replace.

Did you find all pieces of your DISA valve?
GL

[Angel 5]

We fixed the misfire, the engine is running fine, at least for now.

I am not sure about that sensor, but it should be in a good condition and clean (considering that we removed the entire cylinder head to hone and clean it). I am able to rev to red line just fine, no issues.

Yes, I found all the pieces of the broken DISA valve, it was just one large flap. Again, considering that the engine was deconstructed, everything is clean, nice and tidy. The timing chain was replaced while putting everything back together, so I don't have before and after timing chain replacement results.

The only issue that I have, very bad fuel economy.

[Sander-E90]

Originally Posted by Angel 5

We fixed the misfire, the engine is running fine, at least for now.

I am not sure about that sensor, but it should be in a good condition and clean (considering that we removed the entire cylinder head to hone and clean it). I am able to rev to red line just fine, no issues.

Yes, I found all the pieces of the broken DISA valve, it was just one large flap. Again, considering that the engine was deconstructed, everything is clean, nice and tidy. The timing chain was replaced while putting everything back together, so I don't have before and after timing chain replacement results.

The only issue that I have, very bad fuel economy.

Hey! I have the exact same problem with misfiring on cylinder 2. I have also changed all the spark plugs and the ignition coil on cylinder 2. After the replacement, the engine hadn’t changed anything, with the same misfiring problems, engine shaking, engine light blinking and so on. Never had any problems with the engine before this...
What did you do to fix the misfiring problem? Would really appreciate your help!

[Saico]

Notice that cylinders are often listed in firing order not the usual sequence.