http://www.youtube.com/watch?v=ehxL0JaYM9A

Take a listen and tell me what you think. First off, new Code 3 pulley bearing and new idler pulley were already installed trying to address the problem, but the noise got worse, not better. Chrysler dealer did the work and says it's coming from the Supercharger and that will be $6000 to replace. MB Tech did not think it was too bad but said it was not normal. They wanted $3000. I'm preparing to remove the SC and replace it with another used one I got off eBay for $1000. Has 18K miles on it with new Code 3 pulley bearing installed that seemed to be the problem that it. But won't be sure until I complete the job.

 

Not to bring you down, but man that sounds horrible! I don't have a blower, I own a NA one, but I used to have a old muscle car, (Camaro) with a blower and NOS, and the blower never sounded like that. First thought is sounds like bearings. Sorry to read about your problems, but I'am sure you will get it resolved someway.

 

Thanks. Looking for some other SRT6 or SLK32 folks to let me know how their cars sound at idle with the A/C on. The A/C seems to engage the SC. You would suspect it was an A/C clutch problem, but that unit is buried way down on the bottom of the engine. But having it on really makes this sound rough, as shown in the video.

 

First of all there are some square ball bearings in there somewhere.

I would get a garden hose to listen to the sounds and localize them as to the physical source. You could also go to harbor freight to get a mechanics stethoscope for even better localization.

Another test proceedure is to remove the fan belt and start the motor for 20-30 seconds to confirm that the noise is due to an accessorie and not motor noise. I would do this just before I started swapping the s/c swap because you would already have the car ready to break down and it is an easy test to confirm the noise.

Finally THE S/C DOES NOT RUN WITH THE A/C. YOU WILL SEE IT ROTATE AT IDLE BUT IT IS NOT ENGAGED UNLESS THE CAR IS IN GEAR AND UNDERLOAD.

The video explaining this is on http://www.youtube.com/watch?v=h9Exe2rxYgc

The write-up is in
Supercharger runs almost all the time, here is the video, TAA DAAAA - 09-17-2008 , 05:26 AM

Enjoy, WOODY

 

I would go with Woody's suggestions. My car is a nice quiet purring. Your baby is sick(in a bad way). Good luck and let us know what it turns out to be.

MikeR

 

The sound is similar to an air conditioner compressor gone bad. I've got my fingers crossed for you that its not the supercharger. I like Waldig's suggestions. Disconnect the drive belt and see if it goes away.

Les

 

Mine is starting to sound a little like that Not quite as pronounced, but it definitely sounds funny to me. Hopefully we can isolate the problem.......BTW how many miles do you have on the car?? I have just over 50k on mine.

 

Take relief that its just the S/C. At least the car is driveable without it, although slow..... I know i'm not helping but life goes on, at least in this case.

 

I'm willing to bet it's the S/C Clutch..., don't know why, but it's just a hunch. Especially if it got worse after you changed the bearing in the Code 3 Clutch pack. I assume you have tried the OEM Clutch/Pulley back on it.

 

Ohnoesaz, Ugh, no it is an issue cause if it locks up the belt and all accessories go away assuming that there is no additional mechanical damage. This is a sign and you need to heed the warning, think of it as a permonition of things to come. Woody Enjoy.

 

I think Woodys' suggestion is right on. I would run without any accessory and eliminate a bearing as being an issue. Idler pulleys etc have a tendency to let go.

 

Ever hear a wankle engine when the "triange" is broke? Woody is dead on and you might want to check the circumference of your idler and pulley. They may be oblong or oval from warping that's cause a "skip" or missed rotation. Please let us know what the diagonsis is. Good luck and stay calm and focused. Engines and their parts can be fixed.

 

This is strange. My wife just got home and her Ford Expedition sounds very simialiar to this sound. It's when the AC is turned on, it makes almost this same exact sound. I remembered this post and thought I would throw in my two cents. Damn, and the Ford is out of warranty. Gotta go search her problem AC now and see what it's gonna cost me!

 

It does sound bad, but I would check the space between the supercharger pulley back plate and clutch. If it's dragging, you might get this noise. The gap should be around .020". Just make sure you can slip a business card in there. Otherwise, it's probably internal.

 

The video was at idle and thus the S/C could not be engaged. IT is the idler , accessories, or S/C clutch bearing. Unless you are in gear and under load the S/C does not run so I'd tell you that it is not in the S/C. Bearings yes, now which one?
Keep listening Woody

 

It might not be "engaged", but it still spins at idle (either due to engine vacuum, bearing friction on the supercharger pulley, or both; take your pick). I wouldn't say rotor bearings or rotor to case contact is out of the question.

 

Thanks for everyones input. This saga keeps getting better. I agree with Woody that the SC is NOT engaged when the sound is heard. Activating the AC does NOT activate the SC clutch as I had previously suspected. I have now ~$1250 into a second SC and it came with a new Code-3 bearing just like the one I had installed a few weeks ago to try and correct the problem. So now with a 2nd SC and 2nd pulley the noise is just the same as before. No better no worse. I can shoot another video and it would sound the same. Pulley gap is set to .3mm and both old and new unit had the same single shim. Turning on the AC really makes the noise as you hear it on the video. Turn it off and the sound almost goes away (but not entirely). No noise is coming from down low where the AC resides. It's up top. Idler is new and other accesories seemed ok when I had the belt off during the SC swap. Both dealers wanted me the spend big bucks on a new SC and MB tech said the clutch is part of the SC and it can not be repaired at by the dealer. I need to talk to the folks that rebuild these and get their input. New SC runs great but my old SC ran great as well. I have a lot of video footage on the job I just completed (more YouTubes to come). How many of you know where the real intercooler (the one that sits under the SC) is made? Hint: Taco-Bell.

I'm not sure what to think. Noise comes from top side, not bottom side. Can not imagine that two SC's would be bad, making the exact same noise. MB tech said he had not ever heard of an AMG SC going bad. I'm missing something for sure. Had it all apart and both SC's and pullies looked and felt very very OK. No vibration. Rotor inspection showed no signs of wear or tear. Car performs very well except for the noise.

To date: (Car has 42K miles)
New (used 18K mile) SC - $1000
New Code-3 Pulley bearing - $35
New idler pulley - $50
New injector o-rings - $30
New intake gaskets - $20
Labor/diag - $100
Noise - Priceless

 

kldiet, did you run the engine with the belt off when you were getting ready to do the SC change? Any change in the noise? Sorry your work didnt pay off. But you should be able to recoupe some of your money by selling your used SC. Didnt the replacement SC come with a clutch? I thought it was part of the SC. That should have eliminated the clutch as any issue. You are correct, the two SC's would be VERY unlikely to have the same exact problem. Keep up the fight, you will get it resolved.

MikeR

 

You got a S/C for 1000$. How is that possible, where did it come from?

I have a concern that the used s/c may have had a noise making it available? Do you know the pedigree of the old (new) s/c ?

If you change things and they dont change, then you have not changed the problem. I apologize for the circumlocutory logic here.

Again you have this noise at idle, is it there if you drive from a stop at idle and below 5 mph? S/C will be off if you creep up to 5, any gas and its on.

When you start out and go up to 10 or 15 MPH so that the noise of the road does not drown it out, is it the same noise now that the S/C is engaged.

With the belt off is the noise gone?

You have listened to the bearings with a mechanics stethoscope and hear the sounds loudest near the input shaft?

Thanks for the efforts.

Woody

 

Woody, you're repeating yourself!

kldiet, I think Woody is trying to tell ya something.

I'd listen...