[E92_328i_Boston]

This afternoon I changed my oil for the second time @ 5500 miles. I did an initial change at 1,000 when the break-in was complete.

Yes, I know, I am borderline insane changing the oil with that kind of frequency. What can I say? I am old school. I wanted to change it before the winter sets in and today was a perfect chance with temps here in Boston approaching 60*. I have always treated all of my vehicles this way and I've never seen any adverse effects such as using/burning oil later in its life. Given that I bought the car and also the extended warranty, I intend on having this car for a very long time - just like the 01 325Ci that I bought new and drove until I bought my 2008 E92.

Anyway, here's the issue that I noticed including all of the related steps. I know that most of what's below has nothing to do with anything,,,I am simply noting it for the record.

1) drive front wheels onto my ramps in my driveway, e-brake on, car in first gear

2) shut off car and remove key from slot

3) pop hood, remove oil fil cap, remove oil drain plug, drain oil into container, remove filter unit

At this point while everything was draining I noticed a periodic high-pitched electronic whine coming from the engine compartment, which repeated every 30 seconds or so. The noise itself lasted for approximately 2-3 seconds. The repeating pattern was NOT fixed. Sometimes it would make the noise and then not do it again for a minute. Sometimes it would make the noise and then do it again 15 seconds later.

I cannot recall the noise the first time I changed the oil, which was in April @ 1000 miles.

4) change copper washer and replace drain plug to proper torque.

5) replace o-ring gaskets and filter and replace filter unit to proper torque.

6) pour 6.5 quarts of BMW Synthetic 5W-30 into the engine, tighten fill cap, start engine and look closely for any leaks @ the filter or at the drain plug.

7) back vehicle off ramps, drive off. everything seems to be fine. the oil level is reported as OK by the computer.

I cannot tell you for sure if the noise occurred again AFTER I added the new engine oil.

If I had to make an educated guess I would say that the noise had something to do with the fact that no oil was in the engine at that point in time. For example, some kind of sensor was noticing that no-oil condition and then causing some kind of electronic pump or other small device to cycle over and over and over again.

I know that doesn't really make much sense, but that's pretty much all I have to go on.

If anyone would care to comment, I am all ears.

Thank you in advance.

-A

[RedGT3]

electric water pump runing.

[E92_328i_Boston]

Yep, I buy that.

Apparently I am not used to the electronic water pump. My 01 had a belt-driven one.

-A

[bsamoul]

Ya that makes sense

[bimdaddy]

Yeah normal sound. I've heard it too while fiddling around under the hood. That's nothing compares to my wife's e350. It buzzes constantly while parked in our garage.