Offered for your viewing pleasure! E39 BMW spark plugs! 20,000 miles from new!

Background:

Car is 2003 BMW 530i.  Plugs were installed at 125k miles.  Currently 145k miles.  Back when the car was driven infrequently, after a long sit and a damp spell of weather, it set a CEL while running a bit rough on startup.   I pulled a code that indicated misfire, cylinders 3 & 6, I think.  I pulled those coils and plugs to take a look and was surprised that the plugs had that much residue on them.  I cleared the code and it never came back.  Ordered a set of plugs and two coils, and they've been sitting on my dresser for months. 

Yesterday I had a slot in the warm garage available, and I figured why not?  Installed the plugs.  Left the old coils in place.  I'll wait for them to properly fail, as they seem to be fine now.  Car starts, idles and drives remarkably well.

It does however use some oil.  Drips some, and I presume, burns a fair bit.  The stock CCV system was replaced with OEM-type parts maybe six months ago.  No change in oil consumption was observed.  I am debating doing the "O2 Pilot mod."

Plugs are pictured below.  I welcome your observations/comments/remarks/advice/etc.

1) Do the mod. There's no downside as long as you don't have vacuum leaks into the crankcase.

2) Drive harder.

In reply to 02Pilot :

I guess the thing that's been holding me back is that at least one youtuber has warned about the possibility of sucking oil up some hose in the CCV system.  Is that a real concern? 

Not in my experience, or the experiences I've seen related in my thread over on Bimmerforums. Lots of reports in there, and I don't recall seeing any that suffered that problem. In theory, if the hose from the valve cover to the CCV became blocked, it's theoretically possible that the oil could be sucked into the intake, but since the mod also keeps that hose (which is notorious for becoming clogged with emulsion) clear, it's a non-issue. If you're really concerned, put a one-way valve in the drain from the CCV to the pan.

Okay, I'll give it a shot.  Not much to lose, really.  I read about five pages into your thread, then watched "50's kid" video on youtube that clearly shows the two ports involved.  My son is driving the car (mostly highway) and I'm checking the level every couple of days.  I'd say consumption is on the order of a quart every 6-800 miles, but it seems erratic, not predictable, which reinforces the notion that it's occurring only during periods of high manifold vacuum.

Yeah, that's typical for an M54 that's decided to consume oil. I wouldn't be surprised if you see consumption cut to the point that you only have to add a quart every 3 or 4 thousand miles. Mine stopped drinking oil almost completely.

Those plugs really don't look like the right heat range or type for that engine. I'd try some NGKs. 

chaparral said:

Those plugs really don't look like the right heat range or type for that engine. I'd try some NGKs. 

Hard to say if they are 1-2 too cold or it's just oil/really rich mixtures.

I have never had luck with any of those 4 electrode plugs in, well, anything.

It's probably just oil - a quart every 6-800 miles is quite a bit. That said, in my 25+ years of experience with BMWs, the plugs will often look less clean than you'd expect unless the engine is run reasonably hard from time to time. When mine are fully warm, they see the redline almost every time I drive them.

chaparral said:

Those plugs really don't look like the right heat range or type for that engine. I'd try some NGKs. 

 

Plugs pictured are NGK 3199, aka BKR6EQUP Spark Plug, purchased from FCP Euro for 2003 BMW 530i.

I've pretty much always run NGK in almost everything I own.

So, an update. 

This car is being driven about 35 mostly interstate miles twice every weekday, plus a good bit of running around on most weekends.  I check the oil at least once a week.  A few months ago, I was probably pouring a half-quart of the good stuff into the crankcase most weeks.  I estimated consumption in the ballpark of a quart every 500 miles. 

Since approximately the time of the spark plug change, I have noticed a very distinct cessation of oil consumption.  I know this is just coincidental.  I have not yet done the O2 Pilot mod, but the entire CCV system was replaced with new parts about a year ago with no impact on oil consumption. 

How do we explain this happy coincidence?  Only thing I can see causing it would be that the lengthy drives have somehow allowed the oil control rings to improve their ability to seal.

Thoughts?

Part of the problem with the stock CCV system is that the upper hose from the valve cover to the CCV gets blocked up with oil-water emulsion. This is worst in cold weather and short trips. Longer drives might have helped clear some of that, allowing better flow out of the crankcase. That's about all I can think of.

It's worth noting that my whole odyssey that led to developing the mod started with changing the whole CCV and seeing no impact on oil consumption. It's just not a good system stock - not enough vacuum to properly evacuate the crankcase, especially once the rings and valve seals start leaking.