Engine Death Rattle
 

Crap I thought this was strictly an FX45 issue.

I moved the X5 out of the garage to clean the floor and then 15min. later returned it to the garage. The next day after starting the X5 there was a severe engine knock, a check engine light and the cabin filled with exhaust fumes. I let it idle, the engine light turned off and the knocking stopped with no problem since.

Not all FX45 owners had this experience and there was never a clear explanation for the knocking and fumes.

How about the X5 forum experts. I now know to allow the engine to warm up before shutting down but why should this be necessary?

Knowing more about the "exhaust fumes" would tell the story;

If the fumes were white and somewhat odorless, the engine might have sucked some moisture into a cylinder through the air-box?

If the fumes were darker and smelled of oil, a cylinder may have sucked oil past a valve seal?

If the fumes smelled of unburned gasoline, a plug may have fouled or coil shorted?

There may be better or other explanations, but that's my guess. Hope it doesn't happen again.

u know i think i had the same thing happen twice. everytime i did this:

start the car on driveway
park the car in garage
switch off ignition

the next day:
start the car
engine knocks
white smoke out of exhaust
after a few minuts following a few engine restarts
everything becomes normal

what's going on?

so when you had severe engine knock and the cabin filled with exhaust fumes, you continued to let it idle? :confused: good job

I earned this comment and thought I would catch some :stickpoke for allowing the engine to run. I was about to shut down when the check engine light turned off and the knocking stopped.

The rich exhaust fumes continued for awhile longer.

When this occured with the FX it was best to let it run, shutting down would make it difficult to restart.

knocking sound= turn engine off

I refer to this as "car wash syndrome". This happens to my 540, X5 and even my Honda Civic. If I start the car and move it out of the garage to be washed, then after washing it move it back into the garage, the next time I go to start it they idle like crap and the exhaust stinks. After about 30 seconds of driving it clears right up. Now when I'm done washing I quick drive around the block and that prevents the starting issue the next day.

Wow so I guess this is quite common. By the way, anyone has a scientific explaination?

Are you talking about with a hand wash? Never, heard of this...

It has nothing to do with actually washing the car, it's the fact that you start the car, move it a couple of feet and then turn it off. That 10-20 seconds of run time makes the start up the next day rough. I'm not saying it happens to all cars, but it happens to all of mine everytime I do this and it happens to alot of other people over on the E39 board that I also visit. I had a 4-Runner before the X5 and didn't have a problem with that.

I don't know. What he descibed above sounds like a reason
to have the engine checked out completely.

Knocking sound is not good!!! It is normal to have a little Knocking sound upon start up but it only last for about 5 secs. before it goes away. If the sound lasted for a while, then you might have a main bearing problem... Good luck, I agree with noncom, get it checked asap...

Yeah, that is what I believe to have been causing the engine knock and white smoke. Still don't know what's it causing it.

Is it because the engine isn't warm enough to be shut down so some engine oil got into the combustion chamber? So the next time you start up the engine it burns the engine oil causing the white smoke plus the knocks until the engine oil has been consumed?

As I mentioned earlier in this thread, white smoke suggests water in the intake. If the water finds it's way into a single cylinder, knocking will be a symptom until it steams out. If your noticing this after a car wash or a short engine run causing condensation it may be worth looking into the air box and intake for signs of moisture. Good luck

The knock and fumes went on for about 5 seconds and probably would not have been as pronounced outside of the garage.

I did not wash the X5 although it may have been raining that day.

Excess moisture in the intake or combustion chambers sounds like a good explanation. No problems since that event.