- Mar 3, 2011
Hello: We have two BMWs, both bought new and meticulously maintained by me; short OCIs being just one of my extreme maintenance practices (e.g even brake fluid and coolant is changed yearly). I know these cars inside and out and do 100% of the work myself. Both "grew up" on German Castrol 0W-30. Neither engine leaks or weeps a single drop of oil. Neither engine consumes any measurable amount of oil between oil changes; 3K miles for my 2003 330Ci, 3K to 5K miles for my wife's 2011 328i. At 30K miles I switched my wife's 328i from German Castrol 0W-30 to Liqui Moly Leightlauf HT 5W-40. I was happy with Castrol but did the switch for no other reason than to try something different. What I noticed in the switch to LM, both of our BMWs immediately consumed 2/3 to 3/4 quart of oil within the first 100 miles after the oil had been changed. The most recent LM change on my wife's 328i was its fourth using LM. The first time I noticed this rapid oil loss, it didn't really register, other than I topped them off. The second and third time I noticed it on my wife's car, I made a mental note. After changing it for the fourth time (the first switch to LM was at 30K miles, fourth change using LM was at 47K miles), my mental note turned into concern. After this 47K mile oil change, I drove to the grocery and ran a few other errands. Before leaving I checked the oil level after changing and checking for leaks. The oil level read 100% full. But after running around for just 40 or 50 miles, the oil level dropped 1/2 quart (as per the electronic measuring device via iDrive. I've experimented with it, it's accurate.) I made note and topped it off with a half quart. The following morning I drove the car again for some errands. On the 328i the oil level is checked very time it's started. The oil level read full after startup. I drove about 30 miles and had lunch. When I restarted the car the oil level was once again low, this time by about 1/4 quart. So, I'd driven just about 80 or 90 miles and the engine "lost" 2/3 to 3/4 quart of oil. These are grocery and errand runs, not track time! I have noticed this consistently with every single oil change using LM. The same thing happened twice with my 330Ci, the oil level measured in that car using a good ole dipstick (yay!). It is important to note that once this initial oil loss occurs, neither car uses any oil at all for the remaining OCI. Nothing. Several tablespoons at most. Before I change the oil I check the level and both sumps will have remained 100% full up to the max fill level. With the 328i oil change this past weekend, I was bothered enough about it to drain out the LM and swap back to German Castrol 0W-40. The LM had ONLY 128 MILES on it when I drained it. Just 128 miles. Check out the VOA and the 128 mile old UOA from my wife's 328i. Look at how much the LM has thickened in ONE HUNDRED TWENTY EIGHT miles! IMO, there is some wicked evaporation that happens very quickly (the quick oil loss after an oil change), but that evaporation rapidly slows to almost nothing once things "stabilize" (because the engines use no more oil after this). It seems that the NOACK standard is defined as being a ONE HOUR, 250C test with air blowing across heated oil. That seems like a very crude measure - just one hour? But the short duration of the test may also explain the behavior I am seeing with the LM oil. That said, how likely do you think the oil in a big 6.9 quart sump is exposed to 250C heat while running errands on a cool spring day? You may be wondering, since the switch back to Castrol, have I had to add any oil to either car to maintain a 100% full sump. Not a single drop in my 330Ci. In my wife's, about 1/8 quart. I appreciate your comments. I'm not trying to throw Liqui Moly "under the bus". Instead, this is what the BITOG community is all about. Exchanging information, conveying observations, and asking questions. I am doing all that here. I had asked a few questions prior to starting this thread. http://www.bobistheoilguy.com/forums/ubb...t_o#Post4067919 http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4068218/1 Thanks for your time, Scott The VOA (using a different batch of LM, I did a VOA in Nov 2014 to pre-screen the oil before switching to it) The UOA <---just 128 miles on the oil (German Castrol 0W-30 in the earlier UOA column. Nice!) There is no sludge in either motor. Short OCIs have kept things looking like new. This is the 328i. Not that it matters, this is Castrol. The test subjects. As you can see, these are very well cared for vehicles.