E53 M54B30 CEL
 

I have a SES.

Car runs very good. Some hiccups or rough running a couple times a month. Sometimes the SES even extinguishes on its own. Not for too long though.

Codes read by schwaben code reader
P0313/$12 Misfire Detected With Low Fuel
P0300/$12 Random Multiple Cylinder Misfire Detected
P0174/$12 System Too Lean Bank 2
P0171/$12 System Too Lean Bank 1
PO 301 /$12 Cylinder 1 Misfire Detected
PO 302 /$12 Cylinder 2 Misfire Detected
PO 303 /$12 Cylinder 3 Misfire Detected

Failing fuel pump or?

Thanks in advance for your thoughts.

Brad

Has there been any work on intake or fuel injectors ?

The first thing I would do is look for any cracked/ split rubber in the intake boots. Also check the hose and fittings that go to CCV (from valve cover) and brake booster (from intake) Sounds like you might have an intake leak. A smoke test would be my second step.

Thanks for the reply.

No work on intake or fuel injectors while this X5 was in my possession for the last approximately 10,457 miles.

I will take a look at the hoses. Smoke test shouldn't be too hard also.

Thanks again,

Brad

E53 M54B30 CEL
 

If it’s the M54, then whenever I got these codes it was always vacuum related.

On the back of the intake manifold firewall side, right side, when facing the vehicle in the upper corner there are capped vacuum ports. Sometimes the caps come off. Auto zone or any place like it sells packs of the caps. I get the multi pack that has all different sizes, and fit the one that’s most snug.

I’ve blown a few off because of the boost, and when I do these are some of the codes I get.

I forgot to mention your finger tip will get stuck to the tip of the vacuum port if it’s missing the cap.

Thanks for the replies.

I am firmly pointed in the right direction, I think.

Brad

I'm having the same issues. It happens at 1/4 tank of fuel. It's the o ring in the transfer pump. See the current thread about misfiring.

Replaced the lower intake boot.

Had an upper on hand just in case but the existing upper looked fine so I reused it.

DISA holds when covering the vacuum but is not a smooth or steady motion. Since the DISA takes a short time to replace I can do it down the road.

Running better. I am expecting the CEL to extinguish on its own after I put on a few miles.

At the manifold the hose clamps are nearly impossible to access. Picked up a flexible driver which worked nicely. I don't know what else I could have done without it.

There are some spacers on the end of both elbows that I didn't know to move them to the new pieces.

What's next?

Brad

You don't mention a smoke test...Did you do one?

The smoke test was on my list.

See the below picture. Once I saw this I wanted to take care of it and then go from there.

The CEL extinguished after driving 30 miles.

What are the symptoms of a failing disa?

Thanks everyone for their help.

Brad