...2006 BMW 330XI..One morning he started the car and oil began to seep out of the oil cap (the car was about 1 quart low on oil). He immediately had it towed to a shop where they checked for faults and sure enough there was a misfire in cylinder 5 and 6. He was told that until the valve cover was removed, there would be no way to know if the car needed a new engine...Brand new ignition coils, oil and spark plugs.

QUESTIONS:
1. What performance issues were experienced BEFORE that morning?
1a. WHAT caused him to open the bonnet and check the oil filler cap after starting the car that morining?
2. Did the SES light ever come on BEFORE that morning (a misfire lights the SES, at least during the misfire episode and sets a code in DME memory WITH mileage when set saved in Freeze Frame Data)?
3. Were the new coils, plugs and oil change done BEFORE that morning?
4. Why were they done & by whom; were they based upon performance or oil leak issues?
5. What diagnostics were done to determine there was a misfire, cylinders 5 & 6?
5a. Did the "shop" test crankcase pressure in any way -- even as simply as opening the oil (filler) cap with the engine running? I presume you are talking about the FILLER Cap, and NOT the OFH (Oil Filter Housing) Cover that is removed to change the filter?
6. If someone read codes P0305 & P0306, did that someone bother to read Freeze Frame Data to determine the MILEAGE when the codes were set?
7. Has anyone bothered to simply remove the coil cover and check to see if there is oil in the plug wells on those two cylinders?

We can ONLY GUESS without more specific info, but it is possible that:
a) There is a problem with the external oil separator/PCV system that is causing positive pressure in the crankcase (and valve cover area).
b) This positive pressure then causes oil to leak at gaskets (particularly the gaskets around the plug wells), and possibly even at the oil filler cap on top of the Valve Cover.
c) The oil in the plug wells affects the coil plug boots and ultimately causes a misfire.

Unless the "shop" the vehicle was towed to was given or obtained different information from what you have stated here, I certainly would NOT rely on any diagnosis or recommendation made by that "shop." NEW ENGINE because of an oil leak? New engine because of P0305 & P0306? Remove Valve Cover to diagnose a "positive crankcase pressure issue"??? Did the "shop" happen to share their opinion on the CAUSE of oil being expelled from the top of the Valve Cover at the filler cap?

George

 

I am told that valve cover gasket leaks is very common with this engine, so I would guess that is what the problem is.

Once you fix the oil leak, you'll have to replace both plugs and coils since most likely the misfires damaged the coils. You could probably get away with not replacing the coils since its easy to swap out later. You may need new plugs to get it back running again, once you fix the leaks.

As a longshot, check if your car is SULEV. BMW has a 15 yr 150k mile warranty related to emission problems and this would technically qualify as an emission problem (oil leak into engine). It is only in certain states and some BMW dealers may balk on upholding this warranty. I am unsure if the SULEV warranty covers 2006. My 2010 was covered when a coil went bad, got new plugs and coils for free (the shop cost was like $1k). My valve cover gasket would be covered as well if it leaked into the spark plug area.

 

Sorry for the huge wait and thank you for the responses! I have more crucial information about the vehicle! After talking to my buddy, he said that oil was seeping out from the oil filter cap, not the oil filler cap. He did an oil change, replaced the oil filter, and the filter cap no longer leaks. Misfire in cylinder 5&6 is still there. He claims to have replaced the spark plugs, but says the issue still persists. I had him remove the oil filler cap while the engine was running to check for CCV back pressure, but there was none. He also says that the spark plug wells in cylinder 5&6 had no oil in them when he went to change the spark plugs. Last service for the car was an oil change 2,500 miles ago. Thanks!

 

Codes would be helpful to eliminate guessing, but I'm going to "guess" that he's going to need new coils in 5 & 6.

 

That's what I was thinking too. My friend lives two hours away from me, but it looks like I'm going to purchase the car from him. He doesn't really know what he's doing when it comes to fixing cars and cannot afford to have a shop repair it, but I should be able to pull the codes and fix the issue since I've worked on a handful of BMW's. When I get the car, I'm going to order a set of Delphi coils and a set of NGK Iridium spark plugs.

 

Also, I forgot to mention that since the issue, the spark plugs had been replaced (still misfire in 5&6). When he took the car in to the mechanic, the coils were inspected and all of them seem to be functional. What else could be the issue? I highly doubt that both cylinders 5&6 could have developed compression issues at the same time... Maybe when he had a couple of the coils replaced (before the incident), the coils were not the same as OE (I've heard that mixing coil brands can lead to a misfire)? I could just be over reacting... It might just be a simple spark plug and coil service fix.