I've gone by the BMW service schedule for my CPO 2005 BMW Z4 2.5i. All service has been done at BMW dealers including the last Inspection II that was done out of the 50,000 mile free service, which was done at 60,000 mikes. At about 55k miles, my oil light came on, and I added about 1/2 quart of oil. Oil change at 60k miles. At 66-67k miles, I added another 1/2 quart of oil when my oil light came on again. I'm just under 70k miles and my oil light came on two nights ago when I parked my car in the garage, but it hasn't come on since. I assume that i'm probaly going to add another 1/2 quart when I stop at the auto store tonight to buy some mobil 1 sythetic. Before 55k miles i didn't add any oil, what would be the case of this change? Do I need to be worried about this? Also, would this be covered under the 100k mile CPO warranty? BTW, In case this might be pertinant, I got my car with ~13k miles on it when I was living in MD and drove about 50+ miles to work for a few months, moved to boston for 8 months where I had a 25 mile commute to work, then moved to Chicago where I had another 25 mile commute for 14 months followed by a 50 mile commute for 3 months, and now I'm back in md for the past year and a half where I have a 6 mile commute to work. my trip home is often split between 3 miles to the gym, and then 3 miles home. In my last move to baltimore, I came here with about 50k miles on my car. I don't know if it is quincidence, but it seems that I've started adding oil as my commute to work has dropped significantly.
A 1/2 qt. oil consumption in 5,000-7,000 miles would not be high oil consumption at all, especially if the miles are short runs or city driving where the engine run time is double what it would be on the highway. While it's possible that you may have a tiny oil leak or seepage the oil consumption is still quite low.
I posed your question via email to a good friend who is a BMW Service Manager. His response is below: "All I can really say on this is that the older the oil gets, the thinner it gets, the more oil the engine burns. The more miles on the car the more oil it will use as well. It doesn't sound like there is anything wrong, the level sensors are very sensitive, some more than others. That's why you can't compare this with another car. Some cars, the light may not come on until a quart is used. If they don't physically check the level themselves and they take the car in for service, no one knows if it was a quart low or not. That's why you don't hear a lot about this. I believe this is just a case of a very sensitive sensor, normal wear and tear on the engine and oil thinning out after some miles have been put on the car. Without looking at the vehicle, this is only a guess. BMW spec use to be 1000 miles / 1 quart. I haven't seen any paper work on this spec in a while. In any event, CPO warranty covers internal parts in the engine for defects in workmanship and materials. "
1 quart per 1000 miles... YIKES! Maybe back in the day but it seems a modern engine will not get close to this. Or am I in the clouds? A half quart every few thousand perhaps but wow!
Thnaks for the responses! I guess I should have said that I'm not leaking any oil onto the floor of my garage. And I always wash under my hood about once a month including using a rag to wipe down everything that is reachabe by hand...so it's always clean and I would have noticed an oil leak if that were the case. When I saw a bunch of stuff written about the CCV valve going bad and putting excess oil into the crank case I was a bit worried, but I didn't think the symptoms match up exactly, and apparantly nobody else did either. It sounds like it's nothing big to worry about, I've just never driven a vehicle before that I had to add oil... even my 1987 ford ranger with 175k miles on it didn't need oil to be added between oil changes--- But I guess all the other vehicles got an oil change every 3,000 miles so it would have needed to use a lot of oil for me to have to add any. Thanks!
I don't think this is excessive at all, particularly as you increase mileage. I think you can see differences depending upon the changes in driving use yu are talking about. I have a 2008 328i convertible with 13,000 miles, and I've added a modest amount of oil to this already, prior to my first oil change at 7,500 miles. I was going to ask if maybe they forgot the crush washer on the drain plug or under, or overtightened the drain plug, causing leaking. It sounds like this is not the case, you'd likely see some drips on the floor or smell something on the exhaust. The only other thing to suggest is to look underneath the engine, around the oil pan and drain plug and see if there is any residual oil around at all. Regarding your comparison with your Ford Ranger, I think todays thinner synthetic oils are different and can cause some of this usage difference compared to old vehicles and fossil oils. Today's engines also probably run much hotter. I don't know if saying that the engine today is under more pressure is the right thing, but they really are. Similar thought to the hotter high pressure heating and cooling systems on these cars can "use" engine coolant and require it to be topped off as well. Due to the higher pressure and the deposits that can "dilute" or "contaminate" the coolant, this is why coolant should be emptied, flushed and replaced.
Agreed, not excessive. Without getting into the "How many miles before an oil change" discussion, I would take this as my engine saying..."Hey...how about changing the oil now." My old E36 328 never used any oil till it got about 187K on it and then it would burn about a 1/2 qt in 5000 miles. But heck I changed it every 5000 miles. Gots ta treat those engines right ya know!!!
My sedan seemed to use some oil when I was doing 3-4 days straight of speed runs from Maine to Boston this summer.
A little oil consumption on long trips is pretty common as is some with HPDE events. FWIW, some German car companies still say 1 qt. in 600 miles is acceptable oil consumption, though most consumers and techs would disagree. As to the OP's original question, yes if you were changing the oil on your other cars @3,000 mile intervals it's very likely you would not have had to add oil unless consumption was much higher than your BMW.
