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BMW 3-Series (E90 E92) Forum > BMW E90/E92/E93 3-series General Forums > General E90 Sedan / E91 Wagon / E92 Coupe / E93 Cabrio > Smoke and misfire at WOT, replaced CCV and hoses, no luck



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      07-13-2019, 09:32 AM   #1
SnowRacer
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Smoke and misfire at WOT, replaced CCV and hoses, no luck

Have a 2008 328xi that drives fine at part throttle, but whenever I apply full throttle I get a massive white/grey smoke cloud that looks like something out of a James Bond movie. Then it misfires horribly and I have to cycle the ignition to make it run normal again.

Did a lot of research here and it all pointed to a faulty CCV and CCV hoses. The CCV is built into the valve cover so just finished replacing it with a new one (URO) along with a new CCV hose. The old CCV hose was fine by the way.

There are plenty of check engine codes (11 in fact), basically all four O2 sensors and lots of misfire codes. I just replaced the two pre-cat O2 sensors a few weeks before replacing the valve cover, but haven't done the post-cat O2 sensors yet.

The intake seems tight and leak free (replaced the intake manifold gaskets while replacing the CCV hose) and everything attached to it looks good.

Where else should I look? It isn't consuming oil or coolant and doesn't overheat or leak anywhere, but I've run out of ideas on what else it could be. Ignition coils? Injectors? Post-cat O2? Some other odd BMW sensor?

Thanks for your insights.
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      07-13-2019, 10:11 AM   #2
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Is it STILL putting out cloud from tailpipes @ WOT?
If so, it is getting one of these pulled into the cylinders @ WOT (1) Oil, (2) Coolant, or (3) too much Fuel. Of course, it is also possible that the "smoke" is from intermittent spark without injector shutdown.

I would suggest:
1) Clear all codes (after recording code numbers & Freeze Frame Data);
2) Retest. You should use DS and manually shift to see if you get an SES light or Tailpipe "Smoke" at higher RPM (~ 5,000 RPM) in 2nd or 3rd, WITHOUT high LOAD or throttle more than ~ 40%. Then when engine warm, do WOT acceleration in 1st & 2nd to see what happens.
3) Let us know what SES or other warning lights you got, and the Fault Codes you now have, along with FF Data and mileage at time of test causing tailpipe "smoke."
4) Let us know what Scan Tool/Diagnostic Software you have available.

BTW, it is significant what COLOR the tailpipe cloud is (black, gray, white), so it would be helpful if you could have a reliable observer follow you and note that.

Please let us know what you find,
George
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      07-14-2019, 01:44 PM   #3
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Update

George - thank you kindly for your help. Here's what I found following your advice:

1) Recorded prior codes and FF data. Reset them.
2) Retested using DS in both 3rd and 4th gear at part throttle up to 5,000 rpm. No smoke at all. Then did WOT with engine warm in 1st and 2nd. 1st was fine, until it shifted to 2nd and it let out the massive smoke cloud.
3) Codes before, during, after, etc below:
4) Borrowing a Innova 3130 scan tool from AutoZone

Had never reset codes before, and did replace bank 1, sensor 1 and bank 2, sensor 1 O2 sensors a few weeks ago so it looks like those codes are still present.

Including those, before resetting I had:
P0304 - cylinder 4 misfire
P0050 - H02S heater control circuit (bank 2, sensor 1)
P0036 - H02S heater control circuit (bank 1, sensor 2)
P0056 - H02S heater control circuit (bank 2, sensor 2)
P0305 - cylinder 5 misfire
P0300 - random misfire
P0306 - cylinder 6 misfire
P2198 - O2 sensor signal stuck rich (bank 2, sensor 1)
P0036 - H02S heater control circuit (bank 1, sensor 2), this one shown twice
P0056 - H02S heater control circuit (bank 2, sensor 2), this one shown twice
P0306 - cylinder 6 misfire, this one shown twice

After resetting and starting car from cold:
P0036 - H02S heater control circuit (bank 1, sensor 2)
P0056 - H02S heater control circuit (bank 2, sensor 2)

Did the part throttle 3rd and 4th gear at 5,000 rpms as mentioned earlier and then got:
P0304 - cylinder 4 misfire

Did the WOT in 1st and 2nd gear and got:
P0306 - cylinder 6 misfire

The codes since the reset were cumulative as I continued to test... post-cat O2 sensors + cylinder 4 misfire + cylinder 6 misfire.

The freeze frame data from P0036 bank 1, sensor 2 is below:

Fuel Sys 1: OL
Fuel Sys 2: OL
Cal Load: 38.8%
ECT: 210 F
STFT B1: 0.0%
LTFT B1: -6.3%
STFT B2: 0.0%
LTFT B2: -6.3%
Eng RPM: 1043
Veh Speed: 0 MPH
Spark Adv: -10.0
IAT: 115 F
MAF: 1.30 lb/min
TPS: 18.8%
Air Status: OFF
Run Time: 3 sec
Command EVAP: 0.0%
Fuel Level: 24.3%
Baro: 29 inHg

Looks to me like a I need two post-cat O2 sensors and a set of new ignition coils and spark plugs. Car has 132k miles. Not sure of prior maintenance as we've only had it a year.

Does it look like the post-cat O2 sensors and ignition-related misfires are what's causing the massive smoke cloud?

Thanks again,
Gary
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      07-14-2019, 09:15 PM   #4
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Quote:
Originally Posted by SnowRacer View Post
...Including those, before resetting I had:
P0050 - H02S heater control circuit (bank 2, sensor 1)
P0036 - H02S heater control circuit (bank 1, sensor 2)
P0056 - H02S heater control circuit (bank 2, sensor 2)
P2198 - O2 sensor signal stuck rich (bank 2, sensor 1)
P0036 - H02S heater control circuit (bank 1, sensor 2), this one shown twice
P0056 - H02S heater control circuit (bank 2, sensor 2), this one shown twice

After resetting and starting car from cold:
P0036 - H02S heater control circuit (bank 1, sensor 2)
P0056 - H02S heater control circuit (bank 2, sensor 2)
The codes since the reset were cumulative as I continued to test... post-cat O2 sensors + cylinder 4 misfire + cylinder 6 misfire...
Looks to me like a I need two post-cat O2 sensors and a set of new ignition coils and spark plugs. Car has 132k miles. Not sure of prior maintenance as we've only had it a year.

Does it look like the post-cat O2 sensors and ignition-related misfires are what's causing the massive smoke cloud?
Hi Gary,

Has your car had the Breather Heater Recall performed, and if so, WHEN in relation to the start of "Smoke Cloud"?

If you do NOT know, go to the site linked in the attached "E9x References" and enter you vehicle VIN. Prior owner may have sold the vehicle before recall performed, and if you've NEVER registered as current owner, BMW does NOT know how to reach you. See OTHER Link for how to register with BMW so you get recall correspondence, or contact nearest Dealer.

Here is the TIS circuit diagram for the O2 Sensor HEATERS and the Breather Heater, and the simpler circuit for F38 which powers all 5 components. Note that the Orange wires ONLY provide power for the electrical resistance HEATER at each component, and have NOTHING to do with O2 Sensor signal, at least directly (NOR do your O2 Sensor Codes ;-):
https://www.newtis.info/tisv2/a/en/e...ontrol/vF5QqMj
https://www.newtis.info/tisv2/a/en/e...8-fuse/vFbq6N3

Here are the Bentley "Definitions" for your O2 Sensor HEATER Codes:
P0036 | 2C9E | H02S Heater Control Circuit (Bank 1 Sensor 2)
P0050 | 2C9D | H02S Heater Control Circuit (Bank 2 Sensor 1)
P0056 | 2C9F | H02S Heater Control Circuit (Bank 2 Sensor 2)

So WHERE is P0030 | 2C9C | HO2S Heater Control Circuit (Bank 1 Sensor 1)? You holding out on us.

P2198 | 2C2C | 02 Sensor Signal Stuck Rich (Bank 2 Sensor 1)
That is Bank 2, where most of the oil is going and misfire is occurring in #4 & #6, so it may have been deemed "stuck rich" as decreased petrol fueling via the injector pulse modification did NOT cause proper O2 level as measured by the sensor. Probably NOTHING wrong with the sensor, just secondary to oil induction.

Have you checked F38 which supplies power to the O2 Sensor HEATERS, AND the Breather Heater (E65390 in Schematic below). TIS is usually reliable, but in this instance that component is Labeled "Crankshaft Breather heating 1" when obviously it is CrankCASE Breather Heater.

Something is causing oil to be sucked into the intake on hard acceleration (hence cloud of smoke, accompanied by "misfire" due to oil-fouled plugs or TOO RICH fueling from the oil dump.

I've NEVER inspected the Breather Heater, and don't know HOW it is configured, but I suspect that YOURS MAY have a restriction that causes oil buildup until manifold suction is high enough (max Load -- WOT) to pull the stored oil into the intake. This condition COULD have been caused by a bad breather heater which burned out fuse F38, and/or be related to a bad PCV & Oil Separator in the VC you replaced. Check F38 as FIRST STEP.

I would get the recall performed if it has NOT been done. If it HAS been done, and F38 is OK, then check the breather hoses and Breather Heater for oil buildup, and try to figure if that is OLD oil from prior VC issue, or if you still have oil NOT getting properly separated in the VC and drawn into the Intake @ WOT.

My SWAG is that the misfire is secondary to the oil induction issue, and that the "Smoke" is NOT caused by misfire, but rather BOTH the Smoke & the misfire are caused by oil induction.

George
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File Type: pdf E9x References.pdf (218.0 KB, 11 views)
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      07-15-2019, 06:33 AM   #5
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I don't know what is causing the OP's smoking. However, I don't think it's likely that the breather heater is the culprit here.

The heater is external to the valve cover and the PCV valve. It's supposed to prevent freezing of condensate in the CCV hose, which could block the vent circuit. The recall is to address the issue of electrical short circuit and possible resultant fire. It's not that the heater in some way degrades and plugs up the vent circuit.

Just a suggestion, fix the obvious problems first, then worry about the headscratchers. You have persistent post-cat sensor codes so deal with them, don't just assume that post-cat sensor operation is unimportant or irrelevant to your other issues.

I do find it a little suspicious that you had all four sensors give errors at the same time. It's unusual for all to fail at the same time. It might be that they failed sequentially over time, reflecting an abysmal lack of attention from the previous owner but could also reflect a common electrical issue. All four sensor heaters receive a common B+ (through fuse F38 or maybe F04, the latter in the DME box in engine compartment), shared as George pointed out with the breather heater; could be a problem in that wiring.

Last edited by dpaul; 07-15-2019 at 06:41 AM..
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      07-15-2019, 01:31 PM   #6
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Quote:
Originally Posted by dpaul View Post
...I do find it a little suspicious that you had all four sensors give errors at the same time. It's unusual for all to fail at the same time. [As I understand those four codes, they relate to LACK of Voltage (open circuit) in the O2 Sensor HEATER circuit which is separate from the O2 Sensor SIGNAL circuit, and as you confirm below, all FOUR of the Heaters are powered by F38 on his model, on the SAME circuit.] It might be that they failed sequentially over time, reflecting an abysmal lack of attention from the previous owner but could also reflect a common electrical issue. All four sensor heaters receive a common B+ (through fuse F38 or maybe F04, the latter in the DME box in engine compartment), shared as George pointed out with the breather heater; could be a problem in that wiring.
I was NOT suggesting that the Breather Heater directly caused a "restriction" in the PCV Vent to Intake. I was suggesting that heater is on the SAME F38 circuit as the four O2 Sensor HEATERS that show fault codes, presumably for "open circuit" in that heater circuit. That's why I suggested checking F38 and asked if recall had been performed.

Gary states he has only had car for a year. He does NOT state when the Fault Codes or Smoking at WOT first occurred, or if they were present at the time of purchase. He states he replaced BOTH Pre-cat O2 Sensors (NOT sure why ;-), and YET he has same O2 Sensor HEATER codes for Pre-cat Sensors. I don't see any indication for replacing Post-cat sensors for same HEATER circuit codes. If there is some reason that Post-cat O2 Sensors could cause "Smoking" @ WOT, please enlighten me.

Let's see what Gary finds by testing F38 fuse & circuit, and seeing if HEATER codes return. Also what he reports as far as Breather Heater Recall and oil in Crankcase Vent to Intake hoses. I trust you agree THOSE are logical tests & examinations to conduct BEFORE replacing parts?

The ONLY thing I can definitively state from Gary's info provided thus far is that all 4 O2 Sensor heaters, and Crankcase Breather Heater are on same F38 circuit per TIS schematic AND he reports O2 Sensor Heater circuit faults.

That raises the likelihood of Breather Heater restriction (possibly during colder weather over the winter) from lack of proper function of that heater due to short which blew F38. So I'm basically agreeing with your observations, but putting a little more emphasis on the Breather hose restriction causing smoking, causing "misfire", etc. -- JUST a theory at this point, pending MORE INFO.

Thanks,
George
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      07-15-2019, 06:16 PM   #7
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Quote:
Originally Posted by gbalthrop View Post
I was NOT suggesting that the Breather Heater directly caused a "restriction" in the PCV Vent to Intake. I was suggesting that heater is on the SAME F38 circuit as the four O2 Sensor HEATERS that show fault codes, presumably for "open circuit" in that heater circuit. That's why I suggested checking F38 and asked if recall had been performed.

Gary states he has only had car for a year. He does NOT state when the Fault Codes or Smoking at WOT first occurred, or if they were present at the time of purchase. He states he replaced BOTH Pre-cat O2 Sensors (NOT sure why ;-), and YET he has same O2 Sensor HEATER codes for Pre-cat Sensors. I don't see any indication for replacing Post-cat sensors for same HEATER circuit codes. If there is some reason that Post-cat O2 Sensors could cause "Smoking" @ WOT, please enlighten me.

Let's see what Gary finds by testing F38 fuse & circuit, and seeing if HEATER codes return. Also what he reports as far as Breather Heater Recall and oil in Crankcase Vent to Intake hoses. I trust you agree THOSE are logical tests & examinations to conduct BEFORE replacing parts?

The ONLY thing I can definitively state from Gary's info provided thus far is that all 4 O2 Sensor heaters, and Crankcase Breather Heater are on same F38 circuit per TIS schematic AND he reports O2 Sensor Heater circuit faults.

That raises the likelihood of Breather Heater restriction (possibly during colder weather over the winter) from lack of proper function of that heater due to short which blew F38. So I'm basically agreeing with your observations, but putting a little more emphasis on the Breather hose restriction causing smoking, causing "misfire", etc. -- JUST a theory at this point, pending MORE INFO.

Thanks,
George
Got it - misunderstood your point about the breather.

FWIW, no, I don't think post-cat failure in and of itself would cause smoking. But I still suspect that the appearance of codes for all 4 sensors at the same time is somehow at the root of the problem. It's very unusual. Perhaps another possibility for a problem is the DME, which switches all the O2 sensor heaters. I'm guessing the OP could not have purchased the car with any sensor error codes - they would set the CEL and he wouldn't pass an inspection (at least in my state). If so, they all happened on his watch, in a relatively short time.

But I can't reconcile everything - apparently the pre-cat codes went away when the OP replaced them - that obviously doesn't fit with a simple faulty wire scenario. Which is why I started my first post in this thread with IDK.

That said, my SWAG is that a breather heater problem has very little chance of causing the peculiar behavior the OP reports. What I think the OP should do first is find out why the post-cat codes are occurring. There are multiple ways to do this but if the only way the OP can test this is by replacing the sensors, that's what I'd advise.
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      07-15-2019, 09:57 PM   #8
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Gentlemen, thank you both for your insightful analysis. Very much appreciate both of your inputs.

I just checked the F38 fuse and it's not blown.

I received the recall letter about the vent hose heater replacement but haven't taken it in yet for replacement. Will call them tomorrow to schedule that replacement under the recall.

Talked to my son and he said the smoke cloud at WOT just started recently - about 2 months ago. It flagged check engine codes and when I had them read initially it was a long list of O2 sensor related codes, so I replaced the two primary ones. Didn't clear the codes for that until just a few days ago. Those sensor 1 codes haven't come back yet. Now it's just sensor 2 codes for each bank.

Can definitely replace the two downstream sensors, especially now that the F38 fuse checks out okay.

We are in Minnesota and it got down to -38F this winter and he normally just drives about 5 miles each way to school. Everything the vent hose heater is meant to address, so everything was pointing to CCV or CCV hose in all the posts I read about similar smoke cloud issues, but those are both brand new now and the problem continues.

I'll order the downstream O2 sensors and get the vent hose heater valve replaced under the recall.

I didn't check the F04 in the DME box yet though. Can check that tomorrow.

Thank you again,
Gary
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      07-15-2019, 10:04 PM   #9
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Quote:
Originally Posted by dpaul View Post
I'm guessing the OP could not have purchased the car with any sensor error codes - they would set the CEL and he wouldn't pass an inspection (at least in my state). If so, they all happened on his watch, in a relatively short time.
Correct. It had no error codes when we purchased it and ran fine for a year until this recent event when it lit them all up became a smoke cloud generator.

No overheating, no oil consumption (granted.. it could be burning oil during the smoke cloud, but he/we learned not to go WOT until it's fixed, so it runs relatively normal if you only drive moderately).

I suspect if I replace these two downstream O2 sensors and drive moderately it'll be error code free and drive fine.. until we go WOT and then poof.
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      07-16-2019, 06:34 AM   #10
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Just checking on your time line - order of things is important, please verify each line:

-car ran fine for most of a year, no smoke, NO CODES (as suggested by no CEL or actually reading the codes?)

-smoking on WOT noted, CEL NOTED (do smoke and CEL correlate well?), codes for all 4 sensors and misfires on bank 2

-replaced pre-cat sensors (did you do this yourself?), cleared codes, CEL NOTED, still smoke WOT, codes only for post-cat sensors, misfires bank 2

Is this correct?

EDIT: sorry, missed post #8. So smoking closely correlates with CEL caused by sudden death of all 4 sensors and misfire bank 2. Hmm. Would be good to determine if the smoke is from oil or fuel (coolant being unlikely IMO). Has the gas mileage changed? Have you looked at the spark plugs? Oil can kill the sensors and it can kill the cats themselves. I wonder if your cats are degrading, with bank 2 being really trashed.

Last edited by dpaul; 07-16-2019 at 06:43 AM..
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      07-16-2019, 07:16 AM   #11
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Yes, that time line is correct.

All was good, no codes (as seen from no CEL), then smoke cloud at WOT, error codes, misfires, etc.

I replaced front two O2 sensors, those codes didn't come back after clearing.

I don't think mileage has changed, but I'm not the primary driver. Have not looked at plugs yet, but can do that too. Based on what's happening, I'd expect bank two plugs to look a bit different than bank one, if that's the direction most of the oil/fuel dump is favoring.
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      07-16-2019, 07:51 AM   #12
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One additional detail I just remembered this morning: occasionally there was smoke out the exhaust at cold start up too. Just a few times and not consistently. That also started happening after the large smoke cloud at WOT and the error codes.

It hasn't done that again since the valve cover / CCV replacement, but we've only started it a handful of times since. Not enough data yet to be conclusive that it's gone.

Gary
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      07-20-2019, 02:33 AM   #13
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Quote:
Originally Posted by SnowRacer View Post
One additional detail I just remembered this morning: occasionally there was smoke out the exhaust at cold start up too. Just a few times and not consistently. That also started happening after the large smoke cloud at WOT and the error codes.

It hasn't done that again since the valve cover / CCV replacement, but we've only started it a handful of times since. Not enough data yet to be conclusive that it's gone.

Gary
Is the smoke you are getting blue in colour or white? When the engine is smoking at WOT, and misfiring is it making detonation/knocking noises?

You could try and disconnect the breather hose from the valve cover, plug the breather hose so the engine will still run and then try a WOT run. If the smoke is still appearing after trying this then that has ruled out the breather system.

Bear in mind it will probably throw fault codes when the breather hose is disconnected, but may be worth trying as a process of elimination. If it is still smoking it may be an injector. Is your engine an N52k?

Last edited by neilj35; 07-20-2019 at 02:59 AM..
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      07-20-2019, 02:35 AM   #14
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One more question which may seem stupid.... you haven't overfilled the engine with oil by any chance?
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      07-24-2019, 04:03 PM   #15
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Update: got the CCV vent hose heater replaced yesterday under the recall. Cleared the codes, drove it around and still getting the sensor 2 heater control circuit faults on banks 1 and 2. Haven't done a full throttle smoke cloud test yet.

One theory was that the vent hose heater shared an electrical circuit with the O2 sensors and that may have been a cause for those faults. No change as of yet. Next will replace those two post-cat O2 sensors.

Quote:
Is your engine an N52k?
Well.. it's a 2008 328xi. Looked up the engine on realOEM and it shows N51B30A.

Quote:
Is the smoke you are getting blue in colour or white? When the engine is smoking at WOT, and misfiring is it making detonation/knocking noises?
I don't think it's white. Doesn't have that sweet coolant smell, doesn't overheat, and not low on coolant. For that matter, not low on oil either as it only happens for one big cloud then no more.

There are the misfires and it runs like crap until I cycle the ignition, but I don't recall any detonation/knocking noises during the smoke cloud. Will try it again and listen for it.

Oil wasn't overfilled.

But... I do recall during the last oil change when I opened up the oil filter housing cap the oil oozed and oozed out. Didn't expect that. Made a mess everywhere. Was first oil change since we've owned it, but also the WOT smoke cloud didn't start until 2-3 months ago and no oil was added to overfill it.
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      07-25-2019, 09:03 PM   #16
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Miracle

A miracle hath happened!

Finally got to do a half a dozen WOT runs after having the CCV/PCV valve heater replaced under the BMW recall.

No more smoke cloud, no more misfires, no more deluge of fault codes! Unbelievable.

I still do have the O2 heater control sensor 2 faults for both banks (P0036 and P0056), but it runs great. I'll replace those two post-cat O2 sensors soon and then it should be back to 100%.

Just to recap I had already replaced the valve cover which has a built in new CCV, also replaced the CCV hose which I found was perfectly fine after taking it off. Apparently the vent hose valve heater must have been clogged or otherwise dysfunctional enough to create chaos.

A big thank you to George (gbalthrop), dpaul, and Neil (neilj35) for your knowledge, willingness to help, deep troubleshooting abilities, and your wealth of suggestions!

Thanks again,
Gary
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      07-26-2019, 12:27 AM   #17
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Quote:
Originally Posted by SnowRacer View Post
...Finally got to do a half a dozen WOT runs after having the CCV/PCV valve heater replaced under the BMW recall. No more smoke cloud, no more misfires, no more deluge of fault codes!
I still do have the O2 heater control sensor 2 faults for both banks (P0036 and P0056), but it runs great. I'll replace those two post-cat O2 sensors soon and then it should be back to 100%.
Hi Gary,

Good to hear the "Cloud has Lifted"

As previously stated, those two codes suggest a wiring fault rather than a fault in the Post-Cat O2 Sensor Heaters themselves, particularly if BOTH codes for BOTH post-cat heaters occurred at the same time (simultaneous failures of both Sensor Heaters is statistically UNLIKELY). Here is the Code Definition from BMW Fault Code Lookup:
N51 | P0036 | 2C9E | DME: Oxygen sensor heater after catalytic converter Activation | MSV80

Here is the TIS circuit diagram again, followed by F38 circuit:
https://www.newtis.info/tisv2/a/en/e...ontrol/vF5QqMj
https://www.newtis.info/tisv2/a/en/e...xi-lim/vFbq6N3

To me, the use of the word "Activation" suggests an issue with the DME-switched Ground connection, such as a bad connection at Pins #2 or Connectors X62102 & X62202, the two Post-Cat O2 Sensor Connectors, but of course it could ALSO be lack of 12V+ at Pins #1 (Orange wires).

I don't suppose the Dealer tested or reported the functionality or condition of the Breather Heater that was removed in the Recall Procedure(?)

I would recheck F38 if there is NO 12V+ at Pins #1.

George
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      07-26-2019, 06:41 AM   #18
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Quote:
Originally Posted by SnowRacer View Post
A miracle hath happened!

Finally got to do a half a dozen WOT runs after having the CCV/PCV valve heater replaced under the BMW recall.

No more smoke cloud, no more misfires, no more deluge of fault codes! Unbelievable.

I still do have the O2 heater control sensor 2 faults for both banks (P0036 and P0056), but it runs great. I'll replace those two post-cat O2 sensors soon and then it should be back to 100%.

Just to recap I had already replaced the valve cover which has a built in new CCV, also replaced the CCV hose which I found was perfectly fine after taking it off. Apparently the vent hose valve heater must have been clogged or otherwise dysfunctional enough to create chaos.

A big thank you to George (gbalthrop), dpaul, and Neil (neilj35) for your knowledge, willingness to help, deep troubleshooting abilities, and your wealth of suggestions!

Thanks again,
Gary
Great news!

I admit to thinking that it was very unlikely that the heater fault would plug that vent but clearly I was wrong about that.
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