[aceshigh]

Hello. I have a n52 motor with incorporated ccv, and recently replaced the entire valve cover. Part was bmw ordered from fcpeuro. It included gasket/bolts/motor seal/sensor seal. Also replaced all rings on the injectors, and new pre's and post's o2 sensors (Bosch). Also replaced both vanos solenoids from bmw. Fired her up, and she runs great. 50 miles later.
.P0171/P0174. Not leaking any oil around gaskets, and injector housings are bone dry. Wondering if I plugged in the pre or post o2 sensors incorrectly (1 in 2/2 in 1), or if I farked up on my valve cover replacement, and now have an air leak. Just ran it 300 miles today, and averaged 25mpg at 80 mph. Again, those codes showed up after I completed the above work. Thinking I need a smoke test, but wondering if there's anything I'm not thinking of. Thanks for any advice!

--went under the car..o2 sensors can only be plugged into the correct female parts, and the o2's on the valve cover are plugged in correctly.

[tcphoto]

A smoke test should help locate the leak. I would also look at vacuum hoses that are crumbling or cracked. Did you use a torque wrench on the valve cover for correct tightness?

[aceshigh]

Originally Posted by tcphoto

A smoke test should help locate the leak. I would also look at vacuum hoses that are crumbling or cracked. Did you use a torque wrench on the valve cover for correct tightness?

Thanks for the input..Vent valve hose was also replaced with valve cover, and I'm unaware of any other vacuum lines on this particular engine. Torque wrench used on all but the back 4 bolts, as they were not accessible with my wrench.

[gbalthrop]

Originally Posted by aceshigh

... n52 motor [2009 328i E91]...recently replaced the entire valve cover [vent valve hose also replaced]...Fired her up, and she runs great. 50 miles later: P0171/P0174...Just ran it 300 miles today, and averaged 25mpg at 80 mph. Again, those codes showed up after I completed the above work...

If BOTH banks are TOO Lean, then a "vacuum leak" where air, "unmetered" by the MAF Sensor, entering the intake downstream of the MAF, is the most likely cause of the P0171 & P0174 codes. However, Freeze Frame Data which provides a "snapshot" of the engine conditions when each code was set might assist in the diagnosis.

Questions:
1) What Make/Model Scan Tool do you have, or what diagnostic software such as INPA or ISTA?
2) Can your Scan Tool read Freeze Frame Data?
2A) Can your Scan Tool read Live O2 Sensor signals?
3) At what mileage did each code get saved in DME Memory (see FF Data)?
3A) At what mileage did you do the Valve Cover & Vent Hose Replacement?
4) I presume your SES light is lit when either P-code gets saved?
5) At what Engine Conditions (Temp, RPM, Load) was each code saved (per FF Data)?
6) Any Fault Codes OTHER than P0171 & P0174?

Quicker & easier than a smoke test: with COLD engine, after startup, spray Starting Fluid or ether on any vent hoses, including at rear of VC where vent hose attaches, and see if idle speed increases momentarily when spray directed at a certain spot. If so, that is the leak point.

I assume you removed the Air Cleaner Housing and/or other air ducts to access the Vent Hose? If so, make sure they are ALL properly reassembled, downstream of MAF Sensor, and spray all joints with ether in test above.

Please let us know what you find,
George

[aceshigh]

Originally Posted by gbalthrop

if both banks are too lean, then a "vacuum leak" where air, "unmetered" by the maf sensor, entering the intake downstream of the maf, is the most likely cause of the p0171 & p0174 codes. However, freeze frame data which provides a "snapshot" of the engine conditions when each code was set might assist in the diagnosis.

questions:
1) what make/model scan tool do you have, or what diagnostic software such as inpa or ista? --codes were read using torque lite app with a generic plug in obd. I have inpa software on my old laptop, but only used it once for a disa test on my manifold upgrade (done 1 year ago at bpc in raleigh).
2) can your scan tool read freeze frame data? Not sure..sorry
2a) can your scan tool read live o2 sensor signals? I picked up approximately 7v on banks 1 and 2. These numbers would dive down upon engine load (both banks), but bank 2 always seems to take a lot longer to come back up to 7v.
3) at what mileage did each code get saved in dme memory (see ff data)? Wagon has 130k, and codes showed up as car was sitting, warming up before i took my son to school..approximately 50 miles after all the parts were replaced.
3a) at what mileage did you do the valve cover & vent hose replacement? Valve cover was done 50 miles before these codes showed..vent valve hose was replaced when i switched manifolds last year.
4) i presume your ses light is lit when either p-code gets saved? Yes sir!
5) at what engine conditions (temp, rpm, load) was each code saved (per ff data)? Not sure..will see if i can shed some light on it for you. I can say with authority that it triggered while idling, but only after it had warmed up. Sel was off when i started the car, and when i came back outside to leave..it was lit.
6) any fault codes other than p0171 & p0174?--no sir..no pendings either.

Quicker & easier than a smoke test: With cold engine, after startup, spray starting fluid or ether on any vent hoses, including at rear of vc where vent hose attaches, and see if idle speed increases momentarily when spray directed at a certain spot. If so, that is the leak point.

I assume you removed the air cleaner housing and/or other air ducts to access the vent hose? If so, make sure they are all properly reassembled, downstream of maf sensor, and spray all joints with ether in test above.

Please let us know what you find,
george

-- thanks mr. George..i will check on the data i haven't been able to supply you, and get back.

[aceshigh]

Post cat 2 shows same value as post cat 1.
Engine idling, and at 675rpm.

[relative4]

As tcphoto said, the solution is a smoke test.

[aceshigh]

Originally Posted by relative4

As tcphoto said, the solution is a smoke test.

Thank you for the input!

[aceshigh]

Smoked it..its coming from the inner disa, or the vent connection just below. Very frustrating because both of those parts aren't even a year old. Valve cover and injector seals are perfect, so maybe a coincidence..I'm at a loss.

[aceshigh]

Update..my car was in 3 months ago for the ccv heater element replacement. Since that vent hose needs disconnected from the element, and also rhat a tech would not expect a DISA to be in that place on a 09 328i, wondering if he knocked my DISA valve and cracked the seal or housing? No way to prove it, but it is leaking out the bottom of the inner DISA..one inch above where the heating element sits. Anybody think I have a leg to stand on? I installed the new DISA 7 months ago.

[freakystyly]

The inner DISA is held in by 3 long screws from the throttle body side. Sounds unrealistic that a leak would happen from a simple bump with your knuckle. I doubt they even used tools.. The plug being damaged would be feasible but not the actual valve.

[aceshigh]

Update..turns out the ses was actually caused by not one, but two clogged catalytic converters (according to bpc in Raleigh). My patients has run out with this vehicle..so I'm moving on. I have been a devoted bmw guy for a while now, but have lost half of my cars due to either catastrophic engine failure, or a ridiculous 3k repair bill for 2 new converters. Thank you all so much for helping me learn about cars. You guys, and others over at e46 forums, have been so informative and helpful. I have crossed over to the dark side, and theres a '18 ford fusion sport in my garage now...with 5 year bumper to bumper warranty..I'm retired for now!

[relative4]

Totally get not wanting to maintain BMWs anymore. But a Ford Fusion "Sport"? Gross. I give you 6 months in that thing.

[tcphoto]

You lost half your vehicles to catastrophic engine failure? If you've been a devoted BMW guy, you'd know that not every code leads to a specific answer. The lean codes should have been your priority and that $3K repair bill probably isn't necessary. Enjoy your Fusion Sport, it will probably drive fine with minimal issues.

[TunafishE93]

I agree BMW are not for people that likes cars to work. There are many good choices for cars that work; Honda, Toyota, Hyundai.. I would not add ford cars to that list, they can make a truck though..

[gbalthrop]

Originally Posted by aceshigh

...I have a n52 motor with incorporated ccv, and recently replaced the entire valve cover. Part was bmw ordered from fcpeuro. It included gasket/bolts/motor seal/sensor seal. Also replaced all rings on the injectors, and new pre's and post's o2 sensors (Bosch). Also replaced both vanos solenoids from bmw. Fired her up, and she runs great. 50 miles later: .P0171/P0174...Just ran it 300 miles today, and averaged 25mpg at 80 mph...

Originally Posted by aceshigh

Update..turns out the ses was actually caused by not one, but two clogged catalytic converters (according to bpc in Raleigh). My patients has run out with this vehicle..so I'm moving on...

Something doesn't compute here. The ONLY Fault Codes you reported are P0171 & P0174: BOTH BANKS TOO LEAN.

NOW you are saying that some shop in Raleigh tells you that BOTH Catalytic Converters are "clogged".

1) That term generally is used to describe MELTED CATALYST in the Cat that reduces exhaust flow.

2) Melting of the catalyst is generally caused by unburned fuel being dumped into the Cat where it ignites and causes a FIRE within the Cat, melting the catalyst.

3) The MSV80 DME in your (former?) vehicle is programmed to do MULIPLE things if a "Misfire" occurs in one or more cylinders, such as where a coil quits firing a plug: (a) SES light on dash; (b) Misfire Fault code for that cylinder is saved in DME memory; (c) Injector pulse signal to the Fuel Injector for that Cylinder is SHUT OFF so that fuel will NOT be dumped into the cat, resulting in VERY rough running and unmistakable loss of power. The Raleigh shop (or you) would have us believe that happened on BOTH Banks (Cyl 1,2,3; AND Cyl 4,5,6) WITHOUT ANY of those three things occurring. I don't claim to "Know it ALL" but I know enough to at least want an explanation from the shop on HOW that could happen.

4) That condition is NOT caused by TOO LEAN running as was detected in YOUR reports of codes read, but RATHER is caused by the EXACT OPPOSITE: TOO RICH running, where the Pre-cat O2 sensors detect "UN-combined O2" or excess O2, which means MORE fuel was injected into the cylinders than was burned/combined with O2 in the combustion process.

5) You stated that you got 25 MPG at 80 MPH on a 300-Mile trip. You never posted any complaint about power or performance.

I have to call BS on the Raleigh shop analysis UNLESS something happened between first post quoted above, and shop's diagnosis that your are NOT telling us about.

Only thing that anyone on this Forum can learn from this thread thus far is:

NEVER rely SOLELY on the diagnosis of an unknown shop UNLESS you know enough to "cross-examine" that shop (a Tech & NOT a BS Front-office guy) about what tests were conducted, what results were obtained, and all facts relied upon in reaching the "conclusion" or "Opinion" they are offering you.

There is a REASON that any Court of which I am aware (U.S. Senate NOT included, "YET" ;-) requires an expert to identify FACTS upon which he relies as a BASIS for his OPINION.

George

[aceshigh]

Originally Posted by gbalthrop

Something doesn't compute here. The ONLY Fault Codes you reported are P0171 & P0174: BOTH BANKS TOO LEAN.

NOW you are saying that some shop in Raleigh tells you that BOTH Catalytic Converters are "clogged".

1) That term generally is used to describe MELTED CATALYST in the Cat that reduces exhaust flow.

2) Melting of the catalyst is generally caused by unburned fuel being dumped into the Cat where it ignites and causes a FIRE within the Cat, melting the catalyst.

3) The MSV80 DME in your (former?) vehicle is programmed to do MULIPLE things if a "Misfire" occurs in one or more cylinders, such as where a coil quits firing a plug: (a) SES light on dash; (b) Misfire Fault code for that cylinder is saved in DME memory; (c) Injector pulse signal to the Fuel Injector for that Cylinder is SHUT OFF so that fuel will NOT be dumped into the cat, resulting in VERY rough running and unmistakable loss of power. The Raleigh shop (or you) would have us believe that happened on BOTH Banks (Cyl 1,2,3; AND Cyl 4,5,6) WITHOUT ANY of those three things occurring. I don't claim to "Know it ALL" but I know enough to at least want an explanation from the shop on HOW that could happen.

4) That condition is NOT caused by TOO LEAN running as was detected in YOUR reports of codes read, but RATHER is caused by the EXACT OPPOSITE: TOO RICH running, where the Pre-cat O2 sensors detect "UN-combined O2" or excess O2, which means MORE fuel was injected into the cylinders than was burned/combined with O2 in the combustion process.

5) You stated that you got 25 MPG at 80 MPH on a 300-Mile trip. You never posted any complaint about power or performance.

I have to call BS on the Raleigh shop analysis UNLESS something happened between first post quoted above, and shop's diagnosis that your are NOT telling us about.

Only thing that anyone on this Forum can learn from this thread thus far is:

NEVER rely SOLELY on the diagnosis of an unknown shop UNLESS you know enough to "cross-examine" that shop (a Tech & NOT a BS Front-office guy) about what tests were conducted, what results were obtained, and all facts relied upon in reaching the "conclusion" or "Opinion" they are offering you.

There is a REASON that any Court of which I am aware (U.S. Senate NOT included, "YET" ;-) requires an expert to identify FACTS upon which he relies as a BASIS for his OPINION.

George

Car had 117k when I bought, so no clue on fuel trims before that time. Never ran rich since I've owned, and I replaced ALL o2 sensors, vacuum lines, disa valves, valve cover and gasket to try and fix these codes. Bpc said o2's were fine, and that the smoke test they performed show zero leaks. I'm really clueless now, but that is a well known shop, and they certainly seem to have plenty of reliability in the community. I apologize for not being precise on exactly what was done, and helping you learn more.

[aceshigh]

Originally Posted by relative4

Totally get not wanting to maintain BMWs anymore. But a Ford Fusion "Sport"? Gross. I give you 6 months in that thing.

Do some research..I said the same before buying it.

[aceshigh]

[QUOTE=tcphoto;25737761]You lost half your vehicles to catastrophic engine failure? If you've been a devoted BMW guy, you'd know that not every code leads to a specific answer. The lean codes should have been your priority and that $3K repair bill probably isn't necessary. Enjoy your Fusion Sport, it will probably drive fine with minimal issues.[/QUOTE

Read the beginning of this thread..I WAS chasing the lean issue. And being a devoted bmw guy, I guarantee that ANY code will lead you to the exact answer..that's why they exist in the first place. It may be 3 or four different things that need to be checked, because of the code, but it certainly gives you a starting point. My best guess, if the converters have finally taken a dump, is that the previous owner let the ccv go to long, or it was in an accident, or a combination of those things before I got the car.

[aceshigh]

I will recheck codes today, and call bpc to find out exactly why they are saying this. Thanks to those that have provided recommendations.

[aceshigh]

0029f4 and 0029f5 were the codes the shop just read. On my torque lite app..it must've somehow messed up the interpretation (possibly according to advisor). They said because the 02 sensors are new, and are not throwing any other codes (heater malfunction/low voltage), they are assuming them to be working properly. They then smoked the car to rule out any exhaust/intake leaks..none noted. From that information, they reccomend the two cats be replaced. Is it possible it's just a coincidence..that I indeed did have a vaccuum leak, but my cats were also on their way out?

[gbalthrop]

Originally Posted by aceshigh

0029f4 and 0029f5 were the codes the shop just read [Are the P0171 & P0174 (too LEAN) codes still there as well?]...They said because the 02 sensors are new, and are not throwing any other codes (heater malfunction/low voltage), they are assuming them to be working properly. They then smoked the car to rule out any exhaust/intake leaks..none noted. From that information, they reccomend the two cats be replaced...

So the shop did NOT actually test the Cats for air flow or obstruction? AND you got 25 MPG at 80 MPH over 300 mile journey and NO performance issues? Does that actually suggest the "Cats are clogged" and need replacement?
Bentley definitions for 29F4 & 29F5:
P0420 29F4 Catalyst System Efficiency Below Threshold (Bank 1)
P0430 29F5 Catalyst System Efficiency Below Threshold (Bank 2)

Are YOU/the shop aware that running BELOW proper Engine Coolant Temp (due to Thermostat staying open) can cause P0420 & P0430, and if BOTH banks are showing that Fault, running too cold is the MOST likely cause of those codes?

Has ANYONE checked Engine Temp (ECTS signal) during engine operation, or LOOKED AT the Freeze Frame Data associated with the P0420 & P0430 Codes to see WHAT the ECTS-reported TEMP WAS at the moment the Fault Codes were saved?

My SWAG is that FF Data shows ECTS at ~ 160C to 170C. You can drive with "Hidden Menu 7.00" activated so you see ECTS-reported Temp as received by the DME, on your Instrument Cluster as you drive.

I have NEVER experienced either P0420 or P0430 on any vehicle I owned, but I have fixed the cause of P0420 code on a friend's Toyota Camry, by simply changing the thermostat (quick, easy, cheap on that vehicle ;-) and NO more P0420. I realize that you can find all sorts of explanations and "anecdotal evidence" (like mine above ;-) including BMW Fault Code Lookup's "Fault Information" page for this code that states as a FIRST "Service Note":
- If diagnostic fault codes related to the oxygen sensor are logged, then a secondary fault is present
http://www.bmwfault.codes/XMLDiagVie...EANgA3ADAANAA=

Now that statement is NOT terribly-specific. It AT LEAST means "don't immediately condemn the post-cat O2 Sensor(s)." Well, YOUR's are NEW, and it is STATISTICALLY very unlikely that BOTH Sensors went bad at same time. What's NEXT? What "Secondary Faults" should be evaluated and "ruled out"?

I'm NOT suggesting that your shop is being lazy or jumping to conclusions, but like "The Boxer" (Simon & Garfunkel) lyrics:
"Still, a man hears what he wants to hear And disregards the rest"

LOW operating Temp is NOT a well-advertised cause of P0420/P0430 apparently, so don't be too hard on your shop -- just rule it out BEFORE replacing the cats. Here is one Web page found in search of P0420 code:
http://www.myautorepairadvice.com/p0420.html

Note that it reference ECTS in the LAST line of possible causes but does NOT mention the thermostat. That's a bit odd. So just check the ACTUAL ECTS signal to the DME in either of the two was described above (FF Data or Hidden Menu 7.00) and see if Temp is LOW. There are OTHER possible "Secondary" causes, so keep an open (and enquiring ;-) mind and check them ALL out.

George