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Oil smoke at cold start up


This morning I started my 2005 BMW X3, after sitting in the garage all night, with the 3.0 engine and poof, big cloud of smoke, blue, obliviously oil. I would add that this is the first night of below freezing temperatures around here and last winter I had two similar “smoke” incidents on the highway. In all cases, the smoke was intense but brief. The car seems to run fine after the smoke goes away. The car only has 33,000 miles on it. What are my potential culprits?

Does the smoke puff on the highway occur when you take your foot off the gas pedal and look in the rear view mirror? Or does it happen on rapid acceleration?

Your valve guide seals could be leaking, allowing oil to drip into the cylinders overnight. When you start uip the car the oil burns off, creating the smoke.

If the car smokes on hard acceleration, you could have ring problems. In either case have the engine checked out by a qualified mechanic. If this was a 10 year old econobox, you would just keep drivng it and top up the oil.

Last year, the highway smoke happened after changing from one highway to the other, so I first slowed about 10 mph, then accelerated, resulting in the smoke. If it is the valve seals, is this an expensive repair?

EVERYTHING is expensive to repair on BMW’s…How often do you have to add oil??

I haven’t had too add oil ever. It seems to happen infrequently and only when it is cold outside. It’s never happened in warm temperatures.

That might indicate the valve guide seals are brittle in cold weather, and more pliable in warm weather. How often have you changed oil in this car?

Although this valve guyide seal is not too expensive in an economy car, it wil be pricey in a BMW.

It uses synthetic oil, so oil changes are every 10,000 miles. I’ve owned for about one year and only changed the oil once as I don’t drive very many miles (less than 10,000 per year).

In 10,000 miles you have NEVER had to add any oil but occasionally it smokes, correct?

I would check the PCV system from end to end…And I would change my oil more often…

Correct, never added oil before. It happens infrequently, last summer the BMW dealer diagnosed and performed quote from shop invoice “found oil in intake, cleaned oil, replaced crankcase vent value with hoses and installed single wall dipstick tube” Actually this was April 14, 2009 with 27,600 miles on it. So, I’ve driven about 6,000 miles since.

“Found oil in intake” sounds like they found the problem but failed to fix it…There should not be any “oil in intake”…Did you buy this car new?

No, I bought it off a three year lease. It is no longer under warranty.

I have to log off…please, as many helpful comments as possible and I’ll check back later.

I’m unfamiliar with this vehicle. Is it turbocharged? If so, perhaps the seal in the turbocharger is leaking and allowing oil into the air instream.

no, it is not turbocharged.

At this stage I would conclude that the car has had insuffucient oil changes and the resultant premature engine wear is starting to make itself known.

Synthetic oil does not really allow for longer drain intervals, especially with the few miles you drive. Since you have oil in the intake, the crankcase pressure must be pushing this oil out. That can be from too much blowby, indicating excessive engine wear cuased by the previous leasing owner, who problably little or no maintenance.

Somebody has to test this engine and tell you the truth. If you have worn valve guide seals and compression blowby due to worn rings, the repair bill may be very high. Most owners at this stage would just keep and eye on the oil and keep driving.

Who told you that 10,000 miles on synthetic oil is the correct change interval?

In response to your question of Who told the OP that 10k miles on synthetic oil is the correct change interval:

BMW does.

On the BMW X3, there is a computer system that records the conditions that the vehicle is driven, and determines when the oil needs to be changed. As the oil quality deteriorates, there are a series of lights on the dash that indicate the condition of the oil on startup. A series of green, yellow, and red dots under Oil Change Interval.

Here are two manuals for you to read, straight from BMW:


Owners Manual:

It says this quite clearly:

“Time intervals should be followed using the maintenance interval as indicated by the BMW Service Interval Indicator lights on the check control panel in the dashboard.”

And since this car came with the Free Maintenance program when it was bought new, there is a paragraph that says this quite clearly:

“Any authorized BMW SAV center in the United States or Puerto Rico will perform the scheduled or additional maintenance services on your vehicle at no expense to you. The maintenance schedule intervals are based on normal driving conditions and operation.
Should you request more frequent maintenance service, the cost of these services will not be covered by the Maintenance Program.”

And under the “Exclusions from Coverage” section, it reads this:

“Oil changes performed outside the recommended maintenance intervals as indicated by the Service Interval Indicator.”

So, the BMW engineers are the ones who determine when the oil gets changed.
If the driving style of the owner has the computer say that the oil doesn’t need to be changed until 10k miles, then that’s the way it works.

There are lots of other cars out there, that also determine when the oil change needs to occur. Porsche, Mercedes, Audi, etc, are all companies that do this. All of them require very specific oils, that meet their very specific specs, and when the owner uses those oils, the oil change interval is whatever they say it is.

And yes, these oils have additive formulations that will in fact meet the long oil change intervals that these manufacturers state.

As for what might be causing the oil smoke, changes are there is a device on the car that is failing. On my porsche Boxster, there is a device called the Air Oil Separator (AOS). When this part fails, it can allow engine oil from one of the valve cover areas to get sucked directly behind the throttle body assembly, and burned by the engine, causing a huge cloud of blue smoke to pour out the back of the car.

This video is a perfect example:


A crappy engine is the first guess. This should not happen at this age or miles. Did you buy this new? I would contact BMW region manager if the dealer won’t help. This is not correct for this car and it is their problem. This happens and ask them to fix it. It is a BMW problem.

I suspect this car may have had only one oil change in its life; the previoous lease holder may have driven it “vigorously” as BMW drivers tend to do, and neglected the upkeep.

I takes a brave man to buy a lease-return BMW 2-seater. For all you know, they used it for a magazine evaluation, where all the writers got to run the crap out of it for a month…Oil in the air filter is NOT a good sign in a car with only 33,000 miles…Time for a compression leak-down test…

It isn’t a two seater, it’s a BMW X3, which is a four door small SUV based on the 3-series. I am indeed concerned this is happening at such low miles. As for maintance, according to the dealer, all maintence has been done on schedule. Indeed, the computer does watch the oil for the user.