I know that with most belt driven AC systems there is always a thump when the clutch engages. However, I recently noticed that if I turn the switch to either of the normal AC modes while the engine is running, the CLUNK is pretty substantial. Has anyone else noticed this? Is it simply the nature of this particular system or do I need to get this looked at? Keep in mind the dealership is a 25 minute drive from here.

 

I played with this a little more and noticed that it really only seems to occur when the AC switch is turned on (not max) while the engine is at idle. In drive it is nothing more than a loud click. Same thing if the engine is off and the AC comes on with restart, just a loud click. The big clunk I can actually feel through my feet. I'm going to stop by the dealership tomorrow just so they can take a quick look. I'm concerned they won't know anything as the service rep I spoke to said they haven't had any Hybrids through there before. GULP.

 

It sounds a little weird. Granted, I mostly drive with the A/C on (it's been 95-100 degrees recently,) but I've never noticed a 'clunk' when I turn it on. I've had it off a couple of times for short periods, then turned it back on - hard to do without it - and haven't noticed any changes. I have a Ford Escape, not MMH, but these don't differ that much.
I think asking the dealer is a good idea. Since I was worried about getting my hybrid fixed, I talked to the dealer about it. All ford/mercury dealeres should have been detailed in the hybrid (my local dealer hasn't even had one!)
One thing to keep in mind is that the A/C is a standard on both the hybrid and regular Mountaniers. So, your dealer should be able to help you out.

As an aside, I typically took my cars to these 10 minute oil change sites for the regular check. Now, with the added complexity of the electric engine, I'm thinking it would be better just to go to the dealer instead.

 

Hi I know this is an old post, but did you ever figure out what this was? Mine is doing exactly what you describe.

Thanks

 

You're looking at a new clutch, maybe a new compressor. Spray it with some penetrating oil and watch it engage.

 

If your car is >2010 the AC compressor is electric - not driven by belts or the engine. If it is <2010 it is engine-driven and you probably need to replace the clutch at the very least or the compressor itself. If you're lucky (meaning <2010) it won't be too expensive, take it to a reliable A/C shop after figuring out whether the compressor is acutally turning.