***I am new to this forum so if this topic doesn't go here please let me know!

I have an 04 MINI Cooper S 6-speed. I was driving a couple nights ago and heard my car making a noise, so I turned off the A/C to hear better and the noise stopped. I then realized the A/C is what was making the noise, also causing my car to lose power and for the car to vibrate while driving. When the vents are on everything is fine, it is only when I turn the A/C on that the noise and vibrations start. It is still blowing cold air, the serpentine belt is brand new, I have no idea what it is and would like to see if anyone else has had these issues before I take my car apart or spend an absurd amount of money fixing this.

Thanks everyone!

 

Going to move you to the Stock Problems/Issues section.

The AC compressor has a clutch than engages when you turn the AC on so that the belt will turn the compressor. It could be the compressor bearings are going. How good are you with wrenches?

 

I'm pretty good with them so far lol. Is it something I can do myself with standard tools?

 

Something else I should mention that I'm curious about, I just had a new clutch put in. Is this something that could have been affected by basically dismantling half the car? Is it something I could take back to the mechanics who did the work and have them look at for cheap?

 

Internet auto diagnosing is somewhat like playing Marco Polo. If the noise and vibration coincide with turning the AC on then I would focus on anything that the drive belt is moving.

 

The compressor is one of the highest loads the engine has so when it's on it can show a lot of things that don't show up except for high load scenarios. This is amplified due to hot weather conditions when we usually turn on the A/C.

Loss of about 5-10hp is expected when the A/C is on, and it is usually accompanied by a slight whining/wurring noise of the compressor working.

If the bearings go bad in a compressor usually you will get a loud screeching noise or it will just seize and eat the belt.

Some questions that might help:

How many miles on the car?

When you're sitting still with the A/C on does it vibrate?

Did you replace the tensioner with the belt?

When was the last time you replaced the spark plugs / wires / coil?

Did you replace any of the engine mounts when you did the clutch?

Have you checked the condition of the motor mounts?

Did you convert from a dual mass flywheel to a single mass flywheel clutch?

If you can answer all these we should / might be able to get you headed in the right direction.

 

When the clutch was replaced I had a local shop that specializes in MINIs do it, it was way too big of a task for someone who is a beginner mechanic at best.

How many miles on the car? - 125k

When you're sitting still with the A/C on does it vibrate? - yes, also it is making a noise that sounds like a jet engine taking off.

Did you replace the tensioner with the belt? - I am not sure, I can not find the latest bill from the shop so I have requested another one. I do know they put in a brand new serpentine belt.

When was the last time you replaced the spark plugs / wires / coil? - I don't know

Did you replace any of the engine mounts when you did the clutch? - yes they were replaced at the time of the clutch replacement

Have you checked the condition of the motor mounts? - they look brand new

Did you convert from a dual mass flywheel to a single mass flywheel clutch? - I believe they replaced the flywheel with whatever was originally in the car, I know it couldnt be saved. that had to be replaced too.

 

Ok, that's a good starting point.

If the jet engine sound is extremely loud it does sound like you may have a A/C compressor issue. Swapping a clutch wouldn't affect that.

They should have replaced the tensioner and the idler pulley when they did the belt unless they were already replaced recently. They're cheap and easy to do. I would have this done when they replace the compressor.

If you haven't done plugs, wires, coil yet I would inspect them and check for corrosion on the coil terminals, and spark plug wear (check the gap measurement). As for spark plug wires the usual rule of thumb is 10 years of 100k miles for replacement. they may not be related to the A/C issue at this point but its a good idea to know where you stand.

Hope that helps.

 

The AC is still blowing cold air when I turn it on, I just have been driving without it for fear of something completely breaking. The jet engine noise is also accompanied by violent vibrations, if that helps. it sounds more like something is banging on something, it is kind of hard to describe in words when I know almost no technical terms for cars. I just point and go "that thing" lol. (I am working on my terminology lol). I will call the shop today who recently worked on it and ask them if they replaced the tensioner and idler pulley.

 

Can you record a video and upload it to YouTube?

 

I will do that this afternoon. Thanks again!