SOLVED - Engine Failsafe after Valve Cover Seal Replacement for Blue Smoke

[McDonaldD]

New Poster - Long time beneficiary of xoutpost's forum posters. Thank you!
***My first post - this one - has possible solutions for both related and seeming unrelated issues. Please, if you have questions of your own about these, pm me a link to the thread where you have posted your question/create a new thread and I'd be happy to give you any information I can offer…but lets keep this thread on topic***

Rest assured that I have read every forum post on Xoutpost.com (and others) and TIS documentation that I could find pertaining to my post below and I have also scoured TIS documents and repair procedures.

Vehicle:
- 2005 X5 e53
- Engine: 4.4L N62 V8 w/135k Miles
- Not CPO but had 100K mile BMW extended warranty/service contract.
- in San Francisco/Berkeley, CA
- subjected to short traffic-filled drives and/or long highway trips to Tahoe.
- rarely subjected to freezing temperatures

This past weekend (1/11/2013) I replaced my Passenger (US) Valve Cover Seals, Upper Timing Cover gasket, VANOS Solenoid o-rings, vacuum pump o-ring, eccentric motor o-ring, and all sensor o-rings on the valve or upper timing covers. (list of parts below). I seem to have fixed my "blue smoke on acceleration from prolonged idling" issue. However, after reassembling, my test drive revealed my engine stalling/stumbling after entering closed loop/warm operation mode while attempting to accelerate under load (higher gears) while revving above ~2000 RPM. I parked it, checked all (touched) sensor connections for solid connections. Resumed driving but had the same issue. Eventually, the dash showed "Engine Failsafe Prog" but no SES light. I drove it home (a block away) and rechecked the sensor connections, looked for vacuum leaks, and attempted to pull the code with my Dad's Innova 3130 OBD 2 reader.* The DTC was P115A - Specific to BMW and "Unknown." I cannot find any real reference to this code relating to BMWs from Innova or any other source. I have researched this type of stumbing/failsafe and most people point to Mass Airflow Sensor (MAF) or post MAF vacuum leak. OBD II should show a MAF code if it has failed…but hasn't and I have been unable to locate any vacuum leaks. I'd hate to just start replacing parts for the fun of it (mostly because I'm a student at UC Berkeley in my last semester and rapidly running out of savings from when I was working before returning to school). Also, I absent mindedly began cleaning the Valve cover before removing the Cam Shaft Position Sensors from it…so the sensors were submerged in soapy water for a minute or two before I realized my mistake and removed the sensors. The sensors appear wholly sealed and I did not anticipate needing to replace them…again, OBD II provides standard codes for Cam Shaft position sensor (CPS) failure, none of which have been raised by the car's computer. I'm leaning further away from CPS failure as the engine revs to redline (carefully tested) when not under load and also if I manually shift the car…which is why I think my "stumbling" is vacuum or MAF. Less likely, I have considered fuel delivery; but why would this coincidently and suddenly fail on first startup/test drive after a valve cover seal replacement with no prior symptoms?

Is there a way to test a MAF sensor, safely/accurately? What else am I missing? I didn't touch the Throttle Position Sensor (TPS), but I did "manually" operate the throttle plate a few times…could this have effected the TPS? VANOS related, because of the removal of the eccentric adjustment motor? but why would it accelerate strongly without load if it was VANOS related? Its driving me crazy and I only have a week until classes start again…

Parts List:
11127513194 - 1 - Valve Cover Seal Replacement Kit
07119903596 - 1 - Eccentric Motor O-Ring - not valve cover seal (11127518420) that was included in Valve Cover Seal Kit
12141748398 - 2 - Camshaft postion sensor O-Rings
11367513222 - 2 - VANOS Solenoid "Large" O-Rings
11367546379 - 2 - VANOS Solenoid "Small" O-Rings
11667509080 - 1 - Vacuum Pump O-Ring
11147506424 - 1 - Passenger (US) side Upper Timing Cover Steel Gasket

* - USB to BMW OBD II cable is on its way - arrives Tuesday!


History - bear with me
I finally resolved my harsh 1-2 and 2-1 shifting by kindly asking the service department at the San Francisco BMW dealership for a vehicle reprogram because of drivability issues in 4/2012. My X5 had previously been reprogrammed on several occasions, the last of which was 2007. I am mentioning the success of my recent reprograming for those with 2004-06 X5s with V8 and 6-Speed ZF transmissions that are still suffering from transmission/drivability issues that have lacked success w/reprogramming in the past.

The relevance is that the service department's "courtesy check" during the vehicle reprogramming appointment informed me of a leaking passenger-side (TIS "right") valve cover seal. However, not taking a minor oil leak seriously, I was distracted by more pressing maintenance issues like a failing water pump that the dealer's courtesy check did not catch.

After replacing the water pump, idler pulleys (preemptively), and vacuum pump o-ring (previously assumed source of oil leak), I noticed the dreaded cloud of blue smoke coming out of my exhaust when accelerating (after entering Closed Loop/warm engine operation) from prolonged idling in traffic. I assume, now, that I disturbed/exacerbated the oil/vacuum leak by working on/around the timing cover during the water pump and vacuum pump o-ring replacements. As I only began to notice the blue smoke cloud immediately after the repair. Also, oil consumption increased markedly (1qt/~500 miles).

I started with the obvious/easiest possibility and replaced both Pressure Regulating Valves (PRV) and cleaned relevant tubes and the accessible valve cover ports. None of these showed signs of tearing nor clogging but were coated with oil; more so on the passenger side. The passenger side was letting a lot of oil into the intake. Unfortunately, symptoms persisted after cleaning and replacing/cleaning the PRVs.

Through all my continued research of the N62's Crankcase Ventilation System and other "Blue Smoke" causing possibilities, I decided to remove and replace the valve cover seal in lieu of pursuing the valve stem seals...and, possibly, guides .

Upon teardown, the crankcase oil leak appeared to originate from the upper timing cover and/or around VANOS solenoid; the external leak's exact source was ambiguous. I decided to to replace the upper timing cover gasket, vacuum pump o-ring (again), and the VANOS solenoids' o-rings in addition to all seals/gaskets/o-rings/rubber grommets on the Valve Cover itself. Teardown also revealed the significant quantity of oil in my intake manifold, originating from the passenger side PRV and, to a lesser extent, the drivers side PRV.

My plug reads show no sign leaks originating from valve stem/worn valve guides. However, the plugs show no signs of being replaced at the 100,000 mile service interval like the dealer (BMW of Fremont) claimed/billed BMWNA for AND plugs 2 and 3 show signs of gasket failure; allowing slight blow-by gasses but no signs of oil. I can only hope there was no permanent damage from this.

I began cleaning the valve cover and noticed how many potential leak paths, especially vacuum, there are. Each bolt and nut on the N62's valve cover has a rubber grommet that acts as a seal. All of the ones I removed were brittle, cracked, and clearly not capable of holding a vacuum. I believe the passenger side valve and upper timing covers were the source of a massive vacuum leak (as a whole). I doubled my cleaning efforts to ensure that every sealing surface was perfectly clean.

I reassembled and everything appeared to run perfect. My idle was stronger even though it was not noticeably weak before and the power at idle was significantly stronger - I know this because my car could not idle its way up my driveway before…and now it can. All signs point to my vacuum leak being solved. Also, I have no oil leaking from either cover or VANOS solenoids. No oil was present in the vacuum lines or intake manifold after pulling the upper vacuum hose from the PRV to the intake manifold, even after prolonged idling.

My current problem did not arise until I started testing "normal" driving conditions. I still did not experience the cloud of blue smoke, but my engine did start stumbling/cutting out when accelerating under load. I could still accelerate like normal when shifting manually. Engine revs to redline with no apparent issues…unless climbing a hill in a tall gear or accelerating onto the freeway in a tall gear. The dash eventually chimed and displayed "Engine Failsafe Prog." Still no SES/service engine soon light.


SOLVED~My oil consumption/blue smoke cloud issues are resolved, as well as Engine Failsafe Prog that was displayed on the OBC-High display.