New owner! Big problems.....
 

Hi everyone! I bought a used 2010 x5d with 94k on it. Did not buy from a bmw dealer. Guy knew it had problems, didn't disclose exactly what they were, claimed it had an egr issue. Easy enough i thought. He pledged to help cover costs for fixing it. Turns out it had a bad injector first. Had that replaced, used a used one online to save a bit of money and seller helped with the cost. Great.

It also had thrown the scr inefficient error nox sensor 2. Mechanic told me if the error comes up after the injector is replaced to take it in. After a few days the cel came on, few more days the 200 def fluid incorrect alarm and back to the dealer.

In the meantime, I have been frantically reading forums about these vehicles and learning as much as possible. I also learned from vehicle history the scr cat and both nox sensors were replaced at 80k due to scr failure. Took it to the dealer again (if i keep this truck i need to get software asap). They replace the rear nox sensor and tell me i need a new scr cat now... Wtf? I've never heard of a cat only lasting 15k. I asked how they came to this conclusion since its basically brand new, I was told by service manager the flow was tested and its burnt up. Is it possible the bad injector caused the scr cat to go bad? I'd think the dpf would be more likely since it is first in line?

I know how many emissions related posts there are already. Especially related to nox sensors. I know it's also my first post. Are they throwing parts at it now? How do you determine a bad scr cat? I really want this vehicle to work out, but I can't put a ton of money in it. There are some great minds here, hopefully someone can help.

I would start by downloading, installing and getting used to Rheingold (it is not that complicated), same software dealers use for diagnostics (and ripping you off!).
Instructions here.

IMPORTANT: when clearing codes, do not clear them all at once. Clear codes from respective modules by going into module menu and calling delete function there. Deleting codes all at once has a good chance to fry your FRM module (it did mine). This will make sense once you install and connect Rheingold.

So,
1. Settle down, get and install Rheingold (make sure to follow install instructions very carefully). Takes about 2 days, considering long download time.
2. Connect to vehicle, start test. You will get a bunch of modules in yellow color (signaling fault).
3. Go into each module, clear codes by "call ecu function"
4. Drive, wait for check engine or check yourself periodically
5. A registered fault will suggest a test plan. For example, Nox sensor #2 fault will suggest a test plan for it.

Here's something important to understand about the way it dealer diagnostics work: Many test plans followed by technicians do not identify the root cause. Instead, they leave up to the technician's experience and (hopefully) wits to determine root cause. That requires understanding whole system, often really complicated one such as SCR.
That's why, more often than not, inexperienced technicians recklessly throw expensive parts at the problem, at owner's expense.

P.S. This one is likely covered by automatic 120K mile extended warranty on "metering valve" and "scr active tank". You should have received a letter from BMWNA (if not, call them register yourself to receive letters and recalls).
I have a few questions for you, if you don't mind:

1. What were symptoms of bad injector(s)?
2. Was your vehicle drivable after dealer performed the SCR test? "its burnt up" sounds pretty crippling! I was ready to run the SCR test plan a couple days ago. Warnings for this test are saying to make sure to take precautions for high temperature coming out of exhaust. Damage to bumper, etc.
P.S. I am going through investigating "post SCR" sensor fault myself now.

I had a CEL a few weeks ago (45k miles, both NOX sensors replaced 3k miles ago) - went to dealer since shes under factory warranty still until October

-Tech ran test plan, found SCR catalyst inefficiency, ordered SCR cat and reprogramed ECM update

Well call me tickled but after the "ECM Update" the vehicle has not had a CEL come back on for almost 600 miles so although the part is now arrived at my dealer for replacement I am strongly debating whether I should get it replaced now or just tell them to note my file and save it for the future (I'm sure I'll have to do it at some point LOL)

The cel was on for the injector saying number 5 short circuit. Tested with multimeter and value was low. Truck felt like it was missing at times and would go into half power mode.

After they replaced the nox sensor they claimed it went into half power and threw a bad injector on 6.... They tried too drive it before recalibrate the scr maybe? Then they called me after and told me the cat is bad. I'm pushing back pretty firmly against this. Cat don't just burn up.

These NOx sensors have about 50K miles life. A maintenance item, really.
You want both of yours replaced now under warranty than pay $600 for each when warranty expires. That will keep you going at least to 90K.
I strongly suggest you do that.

One more suggestion. Ask to keep the old sensors and keep them.
When any one of these new ones fail, replace with any of the 2 used (they are interchangeable), calibrate and keep going.

Have you looked into the issue with the plastic trims under the hood cracking and allowing the injector harness to get wet and corrode?

Sounds like you have an issue with the injector itself, but still something to double check.

They were completely broke in half. Already purchased and installed replacements. Also took off the foam on the engine. I've been reading a ton about this vehicle.

Does anyone have the numbers which show how much this emission system does to help? I'm interested in the delete, but have a hard time justifying increasing my influence to global warming. If it doesn't significantly increase emissions I may go that route.

OP

was the work at 80k done by a BMW dealer? Should be a 2 year 24k warranty, no??

It was diagnosed by a bmw dealer right before 80k. That is the major topic i discussed with the floor manager today. I can see it on the service report as scr permanent failure. If it wasn't replaced, I'm going to push to have this all done under warranty since someone didn't do their job at a different dealer. I have only owned it 2 weeks, but it does have the refurbished cat from what the first technician told me. They are supposed to be looking into whether or not it was actually replaced.

I have x5d 2010 with 103k miles
possible cause for your scr failure is a faulty thermostat, if you have not had the thermostat replaced already then it's almost 100% certain the thermostat is faulty not allowing engine to reach operating temperature. this can likely cause your cat to fail prematurely.

checking your engine temperature is easy and free you can read about the issue and how to do it on this thread.
https://xoutpost.com/bmw-sav-forums/...-diy-pics.html

My x5 had multiple components replaced glow plugs no2 sensors etc yet dealer never figured out the thermostat was bad since it did not trigger a check engine light.