2010 X5 35d Engine Malfunction - tons of codes!
 

Long time lurker here, first time post! Great information on this site.

I own a 2010 35d with 105,000 miles. Bought new in 2010 and has been rock solid. Have not had one issue and has been one of the best cars I have ever owned! But yesterday I started my car and started driving and immediately the engine malfunction warning came on, lost total throttle response, and check engine light was lit.

I parked the car and pulled up BMWhat. Got a lot of codes and I am wondering what I am looking at here...seems like they could all be related? I have the car at a very reputable indy but they cannot get to it until Monday because the head mechanic is out of town.

• Lower charge air hose monitoring charge air hose - 003F25
• Exhaust gas recirculation rate control, deviation - 004B82
• Measured air mass compared to the calculated air mass too low - 004862
• Particle filter system - 004C5E
• Exhaust gas recirculation control, differential air mass deviation - 004507
• Measured air mass compared to the calculated air mass too low - 004865
• Charge pressure control error - 004530
• Air flow meter signal - 003FF0

Anyone have any bright ideas?

Erase the codes and drive. See which one will reappear. It may be a million things, very hard to say from a distance. Some of the codes show the main problem and others are just secondary, the trick is to figure out which are important ones. You can also do a visual check at the front of the engine where all the charge hoses and EGR stuff is located.

Tried erasing the codes and unfortunately they all reappear. I checked the EGR area and everything looked good. Guess I will have to wait and see what my mechanic says. I will be sure to let all of you know.

For the particle filter code, is that related to DPF or something else?

Could be the MAF or a pipe popped out, but running some test schedules will probably reveal the problem.
DPF is particle filter, but the code is probably caused by the other problems in the system and not DPF itself.

I realize that your codes don't totally match the codes I've seen posted elsewhere for EGR issues, but (since the many of the codes have to do with exhaust gas recirculation [EGR], and your diesel has moderately high mileage) I'm suspicious of carbon build up on your EGR valve and/or throttle valve and/or swirl flaps.

I posted two links that refer to this issue. This link discusses how to get the intake manifold off, then this link discusses cleaning the intake manifold and swirl flaps, and checking the intake valves. To do the full job(s) discussed above would take a fair bit of time, but (if you have the right tools) checking/cleaning the EGR valve and throttle valve can easily be done in 1-2 hours (I'm pretty sure I could do it in 30-45 minutes, but I've been down that road several times and quite familiar with it all).

The EGR valve (part 1) and throttle valve (part 4) can be seen in this link from Realoem:

http://www.realoem.com/bmw/images/diag_7lgb.jpg

The electrical connections to the throttle valve and EGR aren't too bad - though the connector on top of the EGR valve can be a little difficult to disconnect - I discussed using a micro-screwdriver to get it undone in my thermostat link here, and others (posts 60 and 61 of this link) have also found it difficult. If you have the right length of metric hex wrenches, it's not too hard to get the EGR and throttle valves off. Also, using a ball end hex wrench set (like these from Amazon) will allow you to still loosen/tighten the bolts even when it is hard to get the hex wrench perfectly aligned.

Not sure if you're just interested in information, or if you're wanting to try to tackle this yourself. If you want to try to work on it yourself, I can give some other details on the job. Again, not too bad if you have the right length and type of hex wrenches.

I also realize that since I had a fair bit of CBU I want to blame CBU on nearly every other problem I hear about on the diesels. As they say, when all you have is a hammer, everything looks like a nail! So even though I'm suspicious, maybe that's not your issue.

Good luck. Let me know if you want extra details.

One other question - have you noticed a "shudder" when turning off the ignition? If so, it might be a clue that you've got CBU on your throttle valve that is preventing it's normal operation. I'm told (see post #3 on this link) that another name for the throttle valve on diesels is an "anti-shudder valve." I had noticed just such a "shudder" before embarking on my various CBU cleanings about 6 months ago. The "shudder" went away afterwards and (knock on wood) has not yet returned.

And be sure to check out post #23 of this link, the pdf file with pictures is excellent.

From the OP's post I understand that engine did not deteroriated over time, but rather the problem happened suddenly. I would supect cracked/disconnected charge pipe, disconnected connector or sensor malfunction.

Could it be that your battery is on its way out? I know lots of codes appear when the battery is discharging.

First off, thank you so much for your extremely comprehensive response. I have read a lot about CBU, and with my high milage I can totally see this being an issue. Unfortunately I am just way too busy right now to deal with a DIY project...if it was the fall I would do this immediately! But the information you have told me is great to know for the future as I plan on keeping this car for the long haul.

To answer your question about shudder..YES! I have been experiencing a shudder when I turn the car off. I thought it was just me. Guess we are on to something here...

Soon enough I will have a better answer on all of this. A BMW diesel with this high of milage, is there anything I should be doing maintenance wise going forward? The car has been rock solid. Oil/oil filter change regularly as well as air filter change/MAF cleaning every 30k (depending on how the filter looks).

I would trace the charge air lines from the turbos back to the intake manifold. Sounds like something is disconnected. Probably nothing big in my opinion. Good luck.

So got my car back today. Turns out the MAP sensor failed. I got the part back and it was pretty gunked up. Car runs great again with no more codes! :thumbup:

Nice find! How did the mechanic single this one out?

So good to hear that you got it all figured out.

For interest, check out this post - similar issue. Interesting that your code numbers were quite different, but both yours and in the link I just referenced deal with "charge pressure." Also, in both cases the problems were solved with replacement or cleaning of the MAP (Manifold Absolute Pressure) sensor.

So obviously my thoughts about the EGR/throttle valve being the source of the problem were wrong - sorry! Not sure whether the MAP failure was due to CBU, or failure due to another mechanism. If you were really a Curious George, you could clean the old MAP sensor and see if it still worked! Nah - too much work, and things are all good now!

Thanks for posting the resolution of this problem - very helpful.

Wish I knew! I was expecting much worse to be honest. New MAP sensor was $80 plus 2 hours of labor. Not bad at all.

Well going forward I am still a bit concerned about CBU. I talked to my mechanic about it...he suggested that we not worry about it until it becomes an issue. When I have time this fall I definitely want to do an inspection of the EGR/throttle valve. Perhaps a new thermostat is in order too?

I had to replace mine yesterday as well, about 77k miles on my X5. I was able to just lift the air box and get my hand under to unclip the harness and pull the sensor without having to remove the airbox completely.

It helps if you've removed the water trapping sound insulation that covers the intake manifold too

I contemplated on leaving this foam off but put it back in.
What are your thoughts on this, what difference in noise has this made? I was afraid of getting too much noise in the cabin if i removed it.

I suggest you see this thread and them make up your mind

Error code 4B99 and 483D - Bimmerfest - BMW Forums

Looks like ill be removing that dirty thing thins weekend and check for the corrosion issue.