What is going on with my BMW? At low speeds or after I park, I sometimes smell burned oil. When I check the oil level (weekly), it is fine and there is no blue smoke coming from the exhaust. I can’t see any evidence of oil leaks from the top part of the engine (valve covers, etc). I have noticed that the smell seems to be more frequent when I back the car up my driveway (slight uphill incline) before pulling in the garage. I started noticing the burned oil smell over a year ago, but it was very rare. More recently, I am noticing the odor more often. I sometimes catch a whiff in the cabin when I am stopped at traffic light if I have the vent on or sunroof open. I do not get any smell when I am moving. I suspect there is a tiny leak/drip that vaporizes when it hits part of the exhaust system. But why is the oil level not low? And why is the smell so infrequent? My car is a 2001 540ia with 121k miles. I don’t get to drive my E39 very much; my daily, round-trip commute is only 10 miles, all on local roads. All service is up to date, including all of the usual oil-related items: seals, gaskets, etc. I have no codes nor idiot lights flashing. Again, the car uses no oil, according to the dip stick, and there are no puddles under the car (but who knows with the drip guard/splash shield that is snapped under the engine). The power steering fluid is also good, with no leaks. I have not dismantled the filter box to check the brake fluid, but the brakes feel fine. Of course I can’t (practically) check the tranny fluid. I had a rebuilt tranny put in the car three+ years ago and have not had any problems with it. That said, is there any way an ATF “drip†could be getting to the exhaust and giving me this intermittent smell? I have a great indie BMW shop that wrenches on the car but I hate to just give it to them and say “please find an unidentified oil leak (and charge whatever you’d like because I have no idea what is going on).†I would certainly appreciate any comments or insights that anyone has on possible sources for my mysterious burned oil smell. Thank you.
It could be this the Crankcase Ventilation System. Here is a video which shows the DIY replacement of the culprit: http://blog.bavauto.com/10769/diy-v...ventilation-check-valve-cover-how-to-replace/
Thanks for your reply. I actually had the car in the shop for a regular oil change recently and asked the mechanic to take a look for an oil drip somewhere. He confirmed that the valve cover gaskets are leaking (slightly). Once a drop of oil hits the exhaust, I get the burned oil smell. So I am adding the VCGs to my to do list. The leak is very slight and not likely to get much worse in the near future. I'll order the parts and plan to do the VCGs once the weather warms up a bit. Take care and thanks again for your reply to my post.
Hey There Chris, Thank you for the good video. Would you be so kind to confirm that my 2004 545i (160k mileage) may, too, need a crankcase ventilation valve replacement? No hydrocarbons were detected from the coolant reservoir and the engine fault light is from one of the two internal vacuum hoses (code: P0491-secondary air injection system). My car produces white, sometimes with a little bit of blue in it smoke after idling for as little as 15 seconds, but it is not consistent. Some days no smoke is produced other days at almost every third stop light it occurs. Are these signs of a bad crankcase ventilation valve? Is the replacement of the part very similar to the video being that my car is newer? Your time and expertise is appreciated? Mark
You flatter me. My only expertise is remembering where to find the people who actually know this stuff! Your car has the N62 engine, which I know to be a more advanced and higher powered version than the M62 in my 1998. It looks like you may have some symtoms of this problem, but I cannot do much more for you in trouble-shooting your issue. Mike Miller will probably be your best bet. If you read the Roundel, you know what I am referring to. Suggest you send the inquiry to him - he's the real expert around here! Good luck!
thank you, Chris, for your time and referral which I will follow earnestly. Have a nice Holiday Weekend. Ciao