[Greck]

Hi All,
This story is pretty interesting, so don't switch the Tab next 5 minutes. I bought the 335d with 112k miles and 50 miles to no start message from first owner and because of car runs good my initial idea was that the cause of the "No Start" issue is very simple and I can easily fix it. I spent several weeks reading the information about the SCR system and diesel cars because before 335d I had only gasoline cars and based on information that I found I did following:

0. Checked\Cleaned the EGR\Intake\Valves for Carbon
1. Refill the SCR DEF Tank with new BWM DEF
2. Cleaned\Tested the SCR Metering Valve (DEF Injector)
3. Replaced Front and Rear NOx sensors

somewhere in the middle I found a way how to reset the "No Start" message and I finally start driving the car! Wooohoooo! And I got first speeding ticket next day (stupid)

So far I have the error that shows up after each 50-80 miles "4D16 SRC System, efficiency" and SCR System test said that I need to replace SCR Catalytic converter and I replaced the CAT

After 250 miles I got the same error code again...

one more thing that I noticed that I have extra soot on the exhaust pipes... and most of the others 335d or X35D are clean...

The purpose of this topic to figure out what else is wrong, the cost of DPF replacement is really high and before I actually replace it I would like to be 999% sure that it will solve the issue.

Car runs great: fast and smooth, idle is ideal. No smoke and almost no any smell when car is warmed up and running in idle and there is a little bit smoke when you push the gas pedal all the way down on the parking lot.

The ISTA results of DPF tests are attached, it seems like it is not clogged... So I don't understand why I have extra soot...

Please share the ideas... Thank you.

The final list of completed points on my way to fix SCR related issues are:

0. Checked\Cleaned the EGR\Intake\Valves for Carbon
1. Refill\flash the SCR DEF Tank with new BMW OEM DEF
2. Cleaned\Tested the SCR Metering Valve (DEF Injector)
3. Replaced Front and Rear NOx sensors
4. Replaced SCR Catalytic converter
5. Replaced fuel filter (and all other filters)
6. Tested the thermostat (SCR System Test = temp is 90-96C)
7. Checked the "Mixer" position before the SCR Cat
8. Tested EGR Valve with ISTA Tests (PASS)
9. Replaced the DPF
10. Replaced the Thermostat
11. Replaced all thermal sensors on the DPF (I guess that regeneration stucks because of them)

[floydarogers]

With all that stuff replaced, I don't know why you would be still getting 4d16. The DPF isn't really involved in NOx reduction. Although if the Diesel Oxidation Catalyst (in same cannister with the DPF) is bad might affect it.

Are there other shadow codes other than 4d16?
Have you checked the mixer (it's just before the SCR Catalyst and is intended to swirl/mix the DEF and exhaust so as to get complete reduction.)
Only other thing I can think of is the DEF pump in the SCR tank, but you've checked the operation of the DEF Injector (mixer)...

One other thing: my most recent 4d16 was because the engine coolant wasn't hot enough - replaced the thermostat to get it into correct range (I think it was typically 76C or so before, needs to be 87C +.

[Greck]

I tested the thermostat already - temperature is high, like 90-96 during the SCR System Test.

When I replaced the SCR Cat I installed new one with correct mixer position.

[BB_cuda]

Greck, this is the Floyd guy I told you about getting advice from (in your other thread).

[Hoooper]

did you try swapping your nox sensor locations? I cant help but think your only possible remaining issue is that the detection into the SCR is low, or that the detection out is high. I realize you already swapped for new sensors, but you wouldnt be the first to get a bad part from production.

You would get some NOx conversion in the DOC but still I would think that doesnt have anything to do with it since 4d16 claims to be a measure of SCR efficiency, meaning does it meet the expected NOx reduction, not whether it achieves a total NOx number.

[Greck]

Originally Posted by BB_cuda

Greck, this is the Floyd guy I told you about getting advice from (in your other thread).

I don't know who is that and how to contact him...

[Greck]

Originally Posted by Hoooper

did you try swapping your nox sensor locations? I cant help but think your only possible remaining issue is that the detection into the SCR is low, or that the detection out is high. I realize you already swapped for new sensors, but you wouldnt be the first to get a bad part from production.

You would get some NOx conversion in the DOC but still I would think that doesnt have anything to do with it since 4d16 claims to be a measure of SCR efficiency, meaning does it meet the expected NOx reduction, not whether it achieves a total NOx number.

SCR System test shows that NOX sensors reads the same values when system disable the injection of the urea, so I expect to see the same issue even after swapping them... Does it make sense of even despite the fact that they are identical I have a reasons to swap them?

[Hoooper]

Just saw your testing data on the other thread. Looks like the sensors are probably working properly but still might be worth a try.

You might have a bad EGT sensor (or sensors). Looking at the temperatures from the other thread, the EGT before the catalyst is measuring higher than the EGT before DOC and the EGT before DPF, that doesnt make sense and if reading high would have a negative affect on the expected efficiency. In other words, if the EGT before SCR is lower than reported, efficiency of conversion would be lower than expected. You would expect the temp after DOC to be higher than the pre DOC temp if it is operating properly, but there is no reason for the temp to increase across the DPF that I can think of, and certainly not 100C increase.

errr, nevermind it looks like the 249C temp is part of a second test, not related to the first temperatures shown which look like the sensors are measuring similar temps.

[Greck]

Originally Posted by Hoooper

Just saw your testing data on the other thread. Looks like the sensors are probably working properly but still might be worth a try.

You might have a bad EGT sensor (or sensors). Looking at the temperatures from the other thread, the EGT before the catalyst is measuring higher than the EGT before DOC and the EGT before DPF, that doesnt make sense and if reading high would have a negative affect on the expected efficiency. In other words, if the EGT before SCR is lower than reported, efficiency of conversion would be lower than expected. You would expect the temp after DOC to be higher than the pre DOC temp if it is operating properly, but there is no reason for the temp to increase across the DPF that I can think of, and certainly not 100C increase.

So which sensors do you think should be replaced?

[BB_cuda]

Originally Posted by Greck

I don't know who is that and how to contact him...

He just spoke to you in post #2 of this thread.

[floydarogers]

Originally Posted by BB_cuda

He just spoke to you in post #2 of this thread.

Yeah, you can PM me, or whatever. But IMHO I have little additional to add at this point. I had both NOx sensors replaced and that seemed to fix my problem (although I think I have an incipient problem with the DEF tank level sensor.)

[Greck]

Originally Posted by floydarogers

Yeah, you can PM me, or whatever. But IMHO I have little additional to add at this point. I had both NOx sensors replaced and that seemed to fix my problem (although I think I have an incipient problem with the DEF tank level sensor.)

Do you have soot on the exhaust pipes?

[Greck]

Originally Posted by BB_cuda

He just spoke to you in post #2 of this thread.

Oohh) Ok, I see. Thank you)

[Greck]

Do you know how to check Diesel Oxidation Catalyst?

[ingenieur]

Originally Posted by Greck

Hi All,
This story is pretty interesting, so don't switch the Tab next 5 minutes. I bought the 335d with 112k miles and 50 miles to no start message from first owner and because of car runs good my initial idea was that the cause of the "No Start" issue is very simple and I can easily fix it. I spent several weeks reading the information about the SCR system and diesel cars because before 335d I had only gasoline cars and based on information that I found I did following:

0. Checked\Cleaned the EGR\Intake\Valves for Carbon
1. Refill the SCR DEF Tank with new BWM DEF
2. Cleaned\Tested the SCR Metering Valve (DEF Injector)
3. Replaced Front and Rear NOx sensors

somewhere in the middle I found a way how to reset the "No Start" message and I finally start driving the car! Wooohoooo! And I got first speeding ticket next day (stupid)

So far I have the error that shows up after each 50-80 miles "4D16 SRC System, efficiency" and SCR System test said that I need to replace SCR Catalytic converter and I replaced the CAT

After 250 miles I got the same error code again...

one more thing that I noticed that I have extra soot on the exhaust pipes... and most of the others 335d or X35D are clean...

The purpose of this topic to figure out what else is wrong, the cost of DPF replacement is really high and before I actually replace it I would like to be 999% sure that it will solve the issue.

Car runs great: fast and smooth, idle is ideal. No smoke and almost no any smell when car is warmed up and running in idle and there is a little bit smoke when you push the gas pedal all the way down on the parking lot.

The ISTA results of DPF tests are attached, it seems like it is not clogged... So I don't understand why I have extra soot...

Please share the ideas... Thank you.

The final list of completed points on my way to fix SCR related issues are:

0. Checked\Cleaned the EGR\Intake\Valves for Carbon
1. Refill\flash the SCR DEF Tank with new BMW OEM DEF
2. Cleaned\Tested the SCR Metering Valve (DEF Injector)
3. Replaced Front and Rear NOx sensors
4. Replaced SCR Catalytic converter
5. Replaced fuel filter (and all other filters)
6. Tested the thermostat (SCR System Test = temp is 90-96C)
7. Checked the "Mixer" position before the SCR Cat

This is your third thread for the same problem - not sure why....

The DOC (in the front of the DPF housing) has no influence on the NOx reduction of the SCR catalyst.
The ISTA test while effective is done stationary - the DDE monitoring and setting the efficiency fault after driving 50 - 80 miles indicates a problem still exists.

A NOx sensor, just like a wide band lambda sensor (same operating principle essentially) can age and not respond precisely at all times.
Were both the NOx sensors you installed new or used?
Same question concerning the SCR cat. and metering valve (does it ever leak).
...just checked one of your other threads - states new upstream and "used" downstream NOx sensor.
Wouldn't put a used O2 sensor in a petrol engine car right?
What fault details for 4d16 are present when read out with other tools?

[Greck]

Originally Posted by ingenieur

This is your third thread for the same problem - not sure why....

Now it comes to DPF, that is reason to start new topic)

Originally Posted by ingenieur

...just checked one of your other threads - states new upstream and "used" downstream NOx sensor.
Wouldn't put a used O2 sensor in a petrol engine car right?

When sensor cost 4% of the car - I will buy used) (actually when I bought it I decided to test it and return if it doesn't help, but then I found the code about front sensor and bought it too)

Originally Posted by ingenieur

What fault details for 4d16 are present when read out with other tools?

System Test shows that NOx sensors reads the same values... Before I changed them - I had a code for the front NOx.

I drove it for 200miles until CEC comes on and only 4D16 is present. Usually I reset code right after it comes up to prevent "No Start" message, but this time I drove 50-60miles more (total is 250-260miles) and checked the codes... still 4D16 only...

[Greck]

Originally Posted by ingenieur

The DOC (in the front of the DPF housing) has no influence on the NOx reduction of the SCR catalyst.

The question of this topic: Is that possible that extra soot that comes out of DPF because of bad DOC or DPF might cause the SCR issues? Photo of the original SCR cat attached(as you can see there are a lot of soot), I guess that soot decrease the SCR System efficiency... That it the something that I'm trying to figure out... I don't want to replace the DPF and got the same error again...

[Hoooper]

Wait wait wait, you're using a used rear nox sensor? Definitely switch front to back and test again. Used sensors can drift and might seem like they're reading right at some points but be way wrong at others.

[smass]

What does ISTA say your ilevel is? Last year I purchased a 2009 w/ 2010 ilevel and had some really odd issues. I do remember the new style mixer requires an ilevel from late 2012.

[Greck]

Originally Posted by smassey321

What does ISTA say your ilevel is? Last year I purchased a 2009 w/ 2010 ilevel and had some really odd issues. I do remember the new style mixer requires an ilevel from late 2012.

Hi, I don't know what is ilevel is. How I can check it with ISTA?

[135i_vs_]

You can try using BMWhat to see how "efficient" the DPF is during regeneration to reduce the soot mass. It should significantly bring the soot mass down to below 5 or less if I remember.

I know there was a recall by BMW for the SCR, basically they change the whole mid section of the exhaust to solve this problem. When I had 4D16, that is what BMW did under warranty.

[Nadir Point]

Originally Posted by 135i_vs_

I know there was a recall by BMW for the SCR, basically they change the whole mid section of the exhaust to solve this problem.

Best solution would be to change out the entire exhaust turbo-back with the DDE coded to eliminate the emissions entirely. But I understand you are in Commiefornia, so probably not an option.