Strange Noise + Overheating with A/C. Help!

[biodole]

Good Afternoon everyone,

Recently my 04 MM began making a strange noise from the engine compartment while I was parked. I noticed that while parked, with the engine running for around 30 minutes, the engine temp gauge showed that the car was overheating. I turned the A/C off, and the sound continued, and the engine continued to overheat. I drove the car approximately 80MPH on the freeway, which ended up cooling it off and lowered the temp back into the midrange.

I parked the car and shut it off, letting it sit until the morning. The following morning I turned the car on, leaving the A/C off. The sound did NOT happen and the engine did not overheat after leaving it on for 30-45 minutes in the 90 degree south florida sun.

The moment I turned the A/C on, the sound started back up and the engine began to overheat after around 15 minutes or so. Furthermore, when I turned the A/C off manually, without shutting the car off, the sound continued, but the A/C turned off.

The only way for me to make the sound stop and prevent overheating is to shut the car off, and never turn the A/C On.

Here is a video to show the sound and A/C Compressor.

https://youtu.be/0DgON7MY0i4


Do I need a new A/C Compressor? The A/C blows ice cold and the fan works fine. I also checked the radiator fan and saw that it was spinning just fine, :confused::confused::confused:


THANKS!

[justbob]

Sure sounds like a bad compressor to me. Sounds like it's dogging down the engine just to spin it.


Builder Of Badassery

[biodole]

Sure sounds like a bad compressor to me. Sounds like it's dogging down the engine just to spin it.


Builder Of Badassery

I too was thinking it was the compressor, but would that really bog down the radiator fan to the point of overheating??

[RubberCtyRauder]

Has the cooling system been opened at all recently? Any air trapped will cause it not to circulate in these motors. There is a specific procedure to remove any trapped air. let us know if you need a link to it. and I can post or someone else will

[MOTOWN]

Your A/C compressor is toast!

[03blackvegas]

First step, what ever is making that noise, replace it ASAP.

[Fastbob]

I agree that it is likely the compressor, but check the electric fan and make sure it is running properly and not making noise.

[slickster]

Could be bad bearings in the AC compressor pulley. Belt tension or slip can cause other problems for other stuff drivin by the belt. Water pump alt cel etc. at least don't drive with ac on that will cause other problems

[biodole]

Thanks to everyone who replied.

I will replace the A/C Compressor ASAP. Any other recommendations for replacement while I have everything apart?


Also, with regard to the cooling system, no, it has NOT been opened at all recently.