2003 M45 - Grinding noise from engine

[MoeJoe]

2003 M45 - 180,000 km

While parked with AC on, my engine temp gauge went all the way in the red zone. I turned off the engine and waited 10 minutes. Started the car again, did not put the ac and the temp was fine when parked. As soon as I put the ac on again while parked, the engine temp started to climb again. I started driving, and the engine temp started to fall (with the ac on). Any traffic light I stopped at, engine temp started to climb again.

When I got back home I checked the engine coolant tank and noticed sufficient coolant but a thin layer of oil on top of the coolant. I removed the coolant bottle, discarded the old coolant, washed the bottle thoroughly and filled the bottle up with new coolant. Next day after returning home I noticed a thin layer of oil again on top of the coolant. The engine temp rose again when I parked with engine running and AC on. Went down if I drove.

Now I notice this weird sound coming from under the hood when the engine is running (no AC).

[http://www.youtube.com/watch?v=QaEddi4b ... e=youtu.be]

I am not sure what is the problem. Could someone please help if they have any ideas would could be wrong. Thanks.

[sergio1987]

It kinda sounds like a fan trying to start... Did you open the hood and check if your radiator fans are working? my 2 cents

[MoeJoe]

The big fan behind the radiator seems to be working

[DeanM45]

The main radiator fan on your car is hydraulic (oil pump is part of the water pump). Check the fluid level in the canister (on the right side). If fluid level is OK then there is probably a problem in the control circuit (solenoid). Check the level and report back.

[svard75]

Wth oil in coolant overflow tank? What Color is the oil? Does your exhaust smell like burnt sugar?

[atlM35]

If your exhaust fumes smell sweet and you have oil in your overflow tank, your head gasket is probably blown.

[Double E]

Just to be clear on this, the tank you emptied and refilled is only 1/20th or less of the total amount of liquid that needs to be flushed. But don't do that yet....

Have a garage do a simple test that looks for exhaust gasses to be disolved into the coolant and you'll know what you have. Head gasket problem or something else.

Also, next time you put up a vid with a sound from the engine, open the hood & give us a real look around.

Do you also have a check engine light on?