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

[McDonaldD]

A B Able Truck - I'm glad you were able to resolve the flagrant symptoms you observed using a fashioned filter and a scotchbrite pad. I also could not agree more with you on "I believe you should diagnose each vehicle on an individual basis - Regardless of BMW guide/valve stem history." However, the underlying cause of our/your symptoms is not be resolved by your solution - your solution is very risky hack to the PRV system that only solves a few symptoms by stemming the flow of oil into the intake.

But, WHY is oil making its way into the intake? The logical answer is that the PRVs are not functioning as they should. Okay, but WHY did the PRVs tear, plug, or fail to close? Explained below, again, the non-functioning PRVs (torn, plugged, etc.) are still only be a symptom of the larger and underlying problem - The crankcase is leaking and can no longer hold a vacuum (prevent the atmospheric pressure from pushing molecules of "air" past the gaskets and seals, and into the crankcase).

How do I know its a vacuum issue? Again, unless old age or some unforeseen anomaly destroyed your Pressure Regulating Valves (PRVs), the blue clouds of smoke, the rapid oil consumption, and/or the failed PRVs all point to a lack of vacuum in the crankcase - there is a study spring that holds open the PRVs. In order for the PRV to close, the pressure from the external atmosphere must be greater than the the sum of pressures exerted by internal (crankcase) atmosphere + the force required to compress the spring. At equilibrium, exterior and interior pressures are equal - so the force of the spring is what is holding the PRV in the open position. As the vacuum generated by the running engine evacuates the pressure of the interior (crankcase), it leaves only the force of the spring to hold the exterior atmosphere at bay. The force of the spring is designed to be less than the pressure exerted by the exterior atmosphere; leading to the compression of the spring in the absence of an interior pressure (vacuum). So, if the designed/intended levels of vacuum (at all RPM) were present, the PRV would function as designed and would stay sealed; only opening to let blow-by gas through when necessary (force generated by blow-by gas pressure + the spring's ever present force is equal to or greater than (=>) the pressure of the exterior atmosphere.

In addition to only being forced open by blow-by gas pressure - the PRVs and Valve Covers have several safe-guards to prevent oil from making its way into your intake - shields, traps, gravity, etc. However, if a crankcase leak is preventing the PRVs from normal operation, these safeguards become overwhelmed. Only when these safeguards are overwhelmed do we get oil into our intake.

Like you suggested, placing a series of filters would certainly stem the flow of some/most/if not all OIL into the intake - which is good. However, those filters would not stem the flow of unmetered air, from the vacuum leaks, into the crankcase. Your filters are merely preventing oil from passing. Your filters are not returning your vehicle's crankcase ventilation system to its normal working state. Your filters do nothing to stem the unabated, and unmetered flow of atmosphere and blow-by gas into your intake. Those filters certainly do not return your crankcase to a state of vacuum; which is the reason the PRVs are not operating to begin with.

If we were just hacking together a way to prevent the smoke cloud problem, we could just put in the aforementioned filters, plug the holes on the intake, and remove the connecting pipes - effectively venting the crankcase into the atmosphere. Not only is this against the U.S. and CA law, it would also increase the flow water-vapor laden atmosphere into your crankcase. That water vapor in the atmosphere is the cause of the "cheese" people see accumulate in/on their PRVs. Sure, applying your filters might allow you to temporarily pass smog and they would make your car run temporarily closer to "normal"...but those filters would also exacerbate the already unnecessary wear and tear the vehicle was experiencing from the initial problem. Water and oil do not mix. While the original crankcase leaks allow water vapor into your crankcase, the addition of said filters would just compound that issue. The filters would stem the flow of water-vapor just as they stem the flow oil. The filter and the oil that the filter collected would increase the likelihood of fast-moving water vapor colliding with, and trapped inside a droplet of oil (stuck to the filter). When enough oil and water collects, the drop gets heavy enough, drips off the filter and flows back into your motor - where it can cause rust, corrosion, electrolysis, and decomposition of your oil. Best case, the drop "dries" on your filter and you can change the filter. Worst case? Your crankcase acts like a greenhouse and has a large quantity of condensation and water-ladened oil. Unfortunately for the filter solution, the original issue the filters set out to solve would not pose as much of a threat as the filtered solution does. The un-filtered solution provides fewer opportunities for oil and water to collide. So, we already know the unfiltered solution has issues with water vapor - why would we want to compound that issue by collecting it on a "condensation screen" - which the filters would ultimately act as. The symptoms of the problem would not be immediate but it would be a larger problem than had you not placed those filters.

I'm not trying to be mean, I'm trying to explain why your filter solution is, ultimately, not a solution at all. I am trying to make it overtly obvious to the readers of this thread that your filters will ultimately cost them more than fixing the underlying issue - vacuum leaks a la oil leaks.

In a later post, I'll give more in-depth information on where to look, what you're looking for, what you should replace, what overlapping maintenance can be performed, and a list of parts - both required and recommended. Since we're working on cars, a human metaphor seems appropriate: The filter solution suggested by A B Able Truck is like icing a broken leg because you think the swelling is the sole reason your leg can no longer support your weight. The swelling is not the reason you are unable to walk, its the shattered bone. Using your filter method merely suppresses the smoke cloud, oiled intake, and oil consumption. It encourages you to drive around - all the while causing more harm than would otherwise be possible. In reality, immediately fixing the vacuum leaks is your best chance at ever running again. Simply installing a series of makeshift filters is like walking on your broken leg after you have used ice to suppress the swelling - you'll be lucky if you can ever walk again; let alone, run. Driving with a filter solution, such as yours, could lead to internal rusting of your camshafts, crankshafts, etc.; degraded oil performance (read: unnecessary wear and tear on the entire engine; and the filters could be dislodged and pushed into the motor by the humanly-incomprehensible power these motors generate. An overhaul of the valve covers and upper timing covers will be an order of magnitude cheaper than replacing a corroded engine block, rusted crank- and cam- -shafts and so much, much, more. Trying to patch or ignore this problem will likely make your problem infinitely worse.

Just as Valve stem seals are certainly not the problem you are trying to solve, filters before/after your PRVs are definitely not the solution. The parts necessary to overhaul the sealing surfaces of the upper engine are relatively inexpensive - its the labor cost that will get you. The job is not that difficult - its just a lot of parts and tools, space, and time necessary to perform the job over two or three days.

Like I said, my next post(s) will include the parts list, job outline, tricks and tips, and N62 maintenance jobs with overlapping-labor.

[A B Able Truck]

I'm in the learning stages on my engine. The things I have taken into account are:
- The vacuum produced/required by these engines are low. http://www.shipkiller.com/SI%20B%201...ept%202009.pdf
- I have not measured the vacuum but when I pull my dipstick, it appears I have the correct vacuum. This would indicate my crankcase seals are good and I don't have excessive blowby.
- If you compare ventalation systems with all other BMW engine models - The N62 is inferior. They only utilize Labyrith separators in the system. (Page 12)
http://www.bawarec.ru/manuals/7er/e6...7er-e65-12.pdf
On the older N62s with the vacuum line (intake to ccv caps) they instruct you to remove the hose & plug the line. Was the spring tension changed? Also the Variable Intake manifold acts like a giant catch can.

The N63TUs have now incorporated a screen within the system, on top of several separation walls. (Page 11 & 12)
http://prodcds.bmwuniversity.com/lib...U%20Engine.pdf

The N63s use Labyrinth and Cyclone oil separators. (Page 23 & 24)
http://prodcds.bmwuniversity.com/lib...3%20Engine.pdf
Even with those improvements - they still note a warning related to blue smoke.

The N55s have a duct for blow by gas feed into the intake system with a integrated non-return valve. Blow by gas duct with settling chamber, impact plate, pressure control valve and non-return valves.
The N20 & N26 even have a better oil separation system. ( Page 19 & 20) http://prodcds.bmwuniversity.com/lib...0%20Engine.pdf

I would love someone to post several photos of the inside (Labyrinth) of the N62 valve cover. I don't want to take mine off unless I have to.


This was taken from a recent article, as it also relates to the BMW owners oil consumption issue;

PVC-INTEGRATED ROCKER COVERS
One of the most distinctive features of the new LS1 Corvette engine is it's domed valve covers, which house the patent-pending, integrated positive crankcase ventilation system designed to enhance oil economy and oil life, while reducing oil consumption and contributing to lower emissions. The valve covers also hold the individual direct mount coil packs. Between the coil packs, the domed sections of the covers contain baffles that separate oil and air from of the crankcase gases - about 3 times the oil/air separation capability of previous engines.


Engine Oil Consumption
Technical Service SI B11 03 13
This Service Information bulletin replaces SI B11 05 84 dated March 1985.

MODEL: All

Information
All engines normally consume a certain amount of engine oil. This is necessary in order to properly lubricate the cylinder walls, pistons, piston rings, valves and turbocharger(s), if equipped. In addition, engines with less than 6,000 miles will generally consume additional engine oil because the internal engine components are not fully seated (break-in). Therefore, engine oil consumption complaints received prior to 6,000 miles cannot be considered.

Once a new or remanufactured engine has accumulated 6,000 miles, oil consumption can be considered if there is a drastic change in the engine oil consumption rate (e.g., the engine oil consumption rate triples) under similar driving conditions.

Engines equipped with a turbocharger(s) will consume more engine oil than normally aspirated engines (non-turbocharged). The additional oil that is consumed in a turbocharged engine is mainly due to the turbocharger lubrication requirements. Some of the engine oil normally migrates past the turbocharger turbine bearing seals and will enter the intake tract of the engine.

All turbocharged engines also require a complex crankcase ventilation system. The crankcase ventilation system needs to maintain a small vacuum on the crankcase and not allow the crankcase to be pressurized. Pressurizing the engine crankcase can lead to external engine oil leaks and increased engine oil consumption via the piston rings and valve seals. When the load and the boost level of a turbocharged engine is varied, the path of the crankcase pressure is changed. During the crankcase ventilation path transition, a small amount of engine oil will pass through the crankcase ventilation system and is additionally consumed. The additional engine oil consumption of a turbocharged engine, as compared to a normally aspirated engine, is normal and not a defect.

Oil Consumption specification:
- All BMW engines (excluding Motorsport) can consume up to 1 quart of engine oil per 750 miles at any time.
- Due to the increased engine power, all Motorsport engines can consume up to 2.5 quarts of engine oil per 1,000 miles at any time.

Diagnostic hints:
When an oil consumption complaint is received, it may be possible to correct it without performing extensive engine repairs. Check the following frequent causes of excessive oil consumption prior to undertaking any engine consumption analysis or repairs. Submit a PuMA case for assistance.

Proper Maintenance:
Has the vehicle received proper maintenance? Certain external conditions (mainly city driving style and/or high engine loads; poor fuel quality; and extreme ambient temperatures), combined with excessively long oil service intervals, may accelerate engine oil degradation, which may cause premature wear of the engine components. Continuous city driving (stop-and-go traffic); fuels with high olefin content; sulfur and certain aromatic fractions; and very high ambient temperatures are the most influential factors causing premature oil aging and consecutive engine mechanical deterioration.

External Leakage:
The engine should be leak-free before starting any engine oil consumption analysis.

Overfilling:
If the oil level is too high, oil in the crankcase will be thrown against the cylinder walls and consumed. Check the dipstick markings or electronic measurement (as equipped) to be sure of accuracy. The oil level must not be higher than the upper mark.

Engine Oil Viscosity/Quality:
The use of oil with the wrong viscosity rating for operating conditions can cause high oil consumption. Check the Owner's Manual to determine the proper viscosity for prevailing conditions.

Engine Speed and Load:
If vehicle operating conditions are severe, oil consumption will be higher than normal. Extreme load or continuous high engine speed will result in increased oil consumption.

Crankcase Ventilation:
The crankcase ventilation systems use various different crankcase ventilation valves, depending on the engine type. Although the valves all look different, they function similarly, using a spring and diaphragm assembly to control the crankcase pressure. A properly functioning pressure control valve is designed to maintain a slight vacuum (under-pressure) in the crankcase, which assures reliable crankcase venting during all engine operating conditions. One of the results of a malfunctioning crankcase ventilation system can be increased engine oil consumption. Refer to SI B11 03 08 for measuring specifications and procedures.
http://www.shipkiller.com/SI%20B%201...ept%202009.pdf

Turbocharged Engines:
Engines that are fitted with a turbocharger(s) will consume more engine oil than naturally aspirated engines (non-turbocharged engines). In this case, a turbocharged engine could require topping of engine oil more frequently. For vehicles with N63 and N63T engines, refer to SI B11 01 13 for additional details.

****This note was copied from a BMW Technical Training manual
Note: If the exhaust system produces blue smoke, it is necessary to check whether the engine is also drawing oil into the combustion chamber through the crankcase breather, which suggest that there is a fault in the area of the crankcase breather. A clear sign of a problem is an oiled up clean-air pipe.

Operating Fluids & Capacities 1/2013
http://f10.m5post.com/forums/attachm...3&d=1364773133

[Bulk]

Originally Posted by A B Able Truck

On the older N62s with the vacuum line (intake to ccv caps) they instruct you to remove the hose & plug the line.

That is interesting and the first time I've heard that - do you have a link to the service notice related to that. Would be very interesting if that stops the smoke on extended idle issue without making the engine run like shit.....

[phildg2000]

Wow!Thanks for this McDonaldD. My 2005 4.8is has this issue and I'm keen on doing the procedure. I found this procedure online and would like confirmation that this is indeed the way to go:
E63 E64 N62 V8 Valve Cover Removal W/ Pics DIY - Bimmerfest - BMW Forums

Thanks!

[pcb5]

Hey McDonaldD, I assuming no more smoke still? I know I asked back around April..just wanted to see if the problem has shown back up, since.

[sykocis]

Excellent thread. I learned quite a bit from this. I know what project I will be taking on next weekend to solve my blue smoke issue.

[garrett4g]

Originally Posted by McDonaldD

Hey pcb5,


Grab a powerful flashlight, expose your throttle body, and peek past the throttle plate. Look for signs of oil...any sign of oil, especially wetness. Oil means that you have a vacuum issue. A vacuum issue (can be an oil leak) is the cause of your smoke.

More to come...

OK - I have this exact problem, symptoms are exact. 2006 BMW 550i 98,000. So I grabbed a flashlight, exposed the throttle body and took a picture. I believe were looking at oil? Can anyone confirm?

[diyanich]

Guys,

My apologies that I revive such an old thread,but...

1. Could anybody explain to me why N62 has so much crankcase vacuum?

2. Why engine should get a rough idle if the filler cap is removed?

I personally have an M62tu but a friend of mine has one 2005 N62 with some oil consumption and a puff after a long idle.

I totally get that my and his kinds of engines might use different principles,and for sure they do,but mine has a bit of the vacuum and idle isn't getting affected.While his has a lot of suction that sometimes barely lets the filler cap to get removed.
Is there a direct connection of intake manifold to the crankcase other than the PRV?
I hope somebody sheds some light on this.
Thanks a lot.

[A B Able Truck]

Originally Posted by diyanich

Guys,

My apologies that I revive such an old thread,but...

1. Could anybody explain to me why N62 has so much crankcase vacuum?

2. Why engine should get a rough idle if the filler cap is removed?

I personally have an M62tu but a friend of mine has one 2005 N62 with some oil consumption and a puff after a long idle.

I totally get that my and his kinds of engines might use different principles,and for sure they do,but mine has a bit of the vacuum and idle isn't getting affected.While his has a lot of suction that sometimes barely lets the filler cap to get removed.
Is there a direct connection of intake manifold to the crankcase other than the PRV?
I hope somebody sheds some light on this.
Thanks a lot.

The only reason an N62 should have excessive crankcase/intake vacuum is that the engine reverted back to throttle valve operation & the CCVs may not be working correctly. (Probable cause - valvetronics/vanos problem)

[diyanich]

On my M62 if I close the air duct that goes to the air filter while engine is running,the duct gets squeezed and collapses inside during the idle.That means that there's no another major air intake other than through the intake.
But if I do the same with my friend's N62 there's absolutely no difference at idle,it gets a bit worse if he revved a bit and that's it.
That is really odd.

The hoses that go from the PRVs have a decent amount of condensed oil and the intake manifold has some decent amount of oil.No puddles yet,but a thick film to say the least.
Both membranes are good.
Would that excessive vacuum prevent the membranes to close the ports that lead to the hoses and then intake manifold?

Originally Posted by A B Able Truck

The only reason an N62 should have excessive crankcase/intake vacuum is that the engine reverted back to throttle valve operation & the CCVs may not be working correctly. (Probable cause - valvetronics/vanos problem)