[Libby]

Hey everyone.
Long time lurker here and made an account to get some help!
I am taking care of my uncles 2009 BMW 335xi as he is away on a 2 year trip. I have had the car for about 9 months now and no serious problems until now. On my way home from work the car gave me a yellow overheating symbol and then immediately turned to red putting the car in limp mode.

Every time I read on when somebody gets these errors it usually means that the water pump has failed. The thing is, I took the car in to do an oil change by a friend the day BEFORE the overheating errors. This is the second time he has done the oil change on this car. After he did the oil change, I drove around the block 3 times, which took approximately 5-7 minutes and then I parked on flat ground and checked the oil level on the dash which read 3/4 bars from MAX. (75% to max)

I am thinking maybe my oil sensor is off and he might've overfilled it maybe? After the oil change I drove 25km to work and back on the highway going 100km and did the same the next day. (The next day was the day the car went into limp mode.) If the car has been over filled with oil and I drove that much, did I cause a lot of damage to the car? Can you get overheating errors from overfilling and driving?

I also recently checked the coolant level and the float cannot be seen, it is below the brim. I did not get a warning error for low coolant. If I were to get the overheating errors without getting the oil change then I would assume it would be the water pump, low coolant or something else.

I am very afraid that the car might've been over filled and I know that is a very bad thing to do. The sensor said the oil was 3/4 to max so I was sure it was fine, but the overheating errors the day after the oil change is very scary.

I am thinking of buying coolant and topping it off and hoping that, that is the problem. I am also not sure which coolant to buy. Could I buy this coolant from Canadian Tire, (http://www.canadiantire.ca/en/pdp/oe...l#.VOBYVS5zI_h) OR should I just go down to BMW and get some coolant from them?

When I start the car, the fan immediately gets loud.
Should I drain some oil? Is it too late? Did I do too much damage?
I am so scared. This is my uncles car and he trusted me with it and I would hate to break the car from getting an oil change from a friend instead of taking it to BMW or some other professional place to save a few dollars.
Any suggestions? I'm scared out of my mind. I can't sleep. If any other information is needed I will try to post ASAP.

Thanks for reading.

[Efthreeoh]

Some of this makes no sense. You've done two oil changes in 9 months. I guess you are driving your uncle's car a lot. And, it's not your car so why would you take it to someone that is not a professional if you are unsure of his servicing capabilities? Has he ever serviced a BMW and especially a N54 engine?

Aside from that, the CBS will read the previous oil level before the oil change was done until the engine reaches the several different parameters needed for a new and correct reading. I don't think you drove the car long enough to get the correct reading initially. The engine takes 7 quarts, did your friend add all 7 quarts to the engine when he refilled it? The oil level is constantly monitored by the CBS once the correct engine temperature and rpms are reached and the display is updated in 20-minute intervals. I suggest you verify how many quarts of oil your friend added to the engine if he did not add in all 7 quarts then leave it alone until the +1quart notification comes up in a few months. If the CBS is reporting 1/4 quart low, then he didn't over fill it. If it was overfilled, the CBS would report the overfilled condition.

Now regarding the water pump. Oil level and operation of the water pump are totally unrelated. The pump sounds like it is going bad and needs to be replaced. I suggest you take the car to a qualified BMW mechanic and have the car scanned for the water pump fault codes. If the pump intermittently stopped working, the codes will be in the ECU. The codes can only be read by a BMW scan tool. I'd suggest not letting your friend repair the water pump...

[BashShah]

You may have 2 issues.
But oil level and water pump are not related.

Oil quantity should be 6.5 litres.
Drain the oil and put it back in...... Make sure it is 6.5 litres.
Then monitor it. Change oil sensor if problem still occurs.

Also, your over heating is caused by water pump and thermostat.
You need you change them ASAP.

I did it myself so cost was $411.00 for parts.

DN