black06c230

Stopped to get some gas and left the car running. As I re-enter the road from the gas station I start to hear a horrible loud metal noise immediately pull over and turn off the car. Pop the hood things look fine and there is no CEL. Crank it with the hood up to try to determine the location of the noise and isolate it down the the SC, I think. Local PD comes up and lends me tools to cut the belt off. Crank the car again and after 3-5sec the noise returns. The bearings in the SC clutch appear to be fine as they aren't falling out or anything. And the SC clutch assy spins fine manually and seems to not have any extra play. So the officer calls me a tow truck and it is there in about 10min. Get it down to the shop and a friend meets me down there to put it inside until tomorrow when my guy can get down there and look it over.

Below is the video I took any thoughts? Again it cranks fine and had been running fine up until stopping to get the gas (Chevron always) and the noise starts after 3-5sec of being cranked. I have the new smaller SC pulley here at the house and will take down to the shop tomorrow to have them put it on see it if helps. I don't know how the internal parts work on the SC and what could be messed up inside there. Video seems to make it louder than it really is.

http://youtu.be/TULB70w7dLY?t=4s

WHTEVO

That definitely sounds bad. Doesn't really sound like anything inside the engine itself so that may be some "good" news. Although i could be wrong. Hard to diagnose where a sound is coming from in a video. Does the sound stay constant while running? Sounds like possibly the supercharger. Curious if it still has any oil in it or if you have any fluid leaks near it. You wouldn't think it should be making any noise if it has no belt though. Good luck finding the actual issue and cause.

Aaron

WHTEVO

You can also seem to hear a weird sound as soon as the car does start up right before it makes the louder noise. Anything noticeable you can see further down near the crank? Again, good luck.

Aaron

black06c230

Haven't let the the car run for very long for fear of doing further damage until I can better locate the source. How would I check the SC for lack of oil? I have not seen any leaks at all.

Crank pulley seems to be fine with no play in it also.

E55Greasemonkey

Next step is to remove (take it off don't cut it off) the accessory belt, and start the engine to see if noise is gone. Also, check your flywheel/torque converter bolts to make sure none of them have backed out.

Forrest Gump 9

It really hard to tell on the video. Did you check the oil and coolant? Any oil out the exhaust? Good luck man.

GT-ER

Yes, this is the same thing I was going to suggest. The noise sounds BAD, my power steering pump sounded nearly as bad ( slightly different, but really bad ) when it broke.

Remove the accessories belt, start the car and let it run ( you can drive it if you want, just watch for coolant temps. It should give you a good 5-10 minutes of easy driving though ). If the noise goes away, check your accessories one by one.

cal1

Keep in mind, at idle, no load or low load, the SC is not engaged. That said, it seems the noise must be coming from something other than the SC.

GT-ER

While it is not engaged, it does spin because of airflow moving through it. Don't rule it out just yet.

black06c230

Thanks guys we will start with the ideas you all have thrown out there. Keep them coming and I will keep you all updated!

Thanks
H

black06c230

This is our main thought at this point.

cal1

Airflow at idle when the car is not moving? I did notice that the pulley on the clutch pak appears to be spinning even without the belt on it. It seemed strange to me. Could it be airflow from the radiator fan causing it to spin?

shardul

iTrader: (1)

It seems like the sound is coming from the lobes of the super charger.

AMGPilot

Yup the vac being puled by the motor. Air's gotta get in somehow

GT-ER

Airflow inside the engine. Even at idle the engine consumes air.

cal1

thanks, so is it almost a partial vacuum that is pulling the SC?

chawkins2001

It sounds like a scene from the blair witch project. If you discover your blower is hurt, hit me up, I have a spare with 52k miles on it.

GT-ER

At idle the engine is at vacuum because the air pressure is below atmosphere but there is a decent enough amount of air flowing to be able to feed the pistons and maintain an idle. This airflow cause the supercharger to spin.

Forrest Gump 9

If you're worry it's the SC, start the engine and grab the black magnet to stop the SC, see if that stops the noise.

03'55AMG

I would use a strap wrench and put it on the SC and have someone start the car. I also hear noises WHILE cranking, before idle. curious to see what this is.
Also, the sound seems to start AS the supercharger pulley starts to spin. I am guessing SC issues. But, what would cause this to happen? You said the car was running while you fueled up, but it didnt make noises till you began to pull out of the gas station? If your like me, the SC always engages while i am pulling out of the gas station to merge into traffic. I don't see what could have caused this though.

fly2nite

Best method I've found for isolating a noise is buy some plastic or foam tubing from home depot a few feet long, put one end in your ear and use the other to locate the source of the noise. It acts as a bullet mic and isolates the sound. Good luck!

03'55AMG

Yea, good method ^^ Always works for me. Also previously mentioned before on here, a long screwdriver works too.

black06c230

Yes drove 7mi reaching 80mph on the interstate this morning to breakfast and then about .5mi to the Chevron. No noises or concerns until pulling back on to the road from the gas station. This is why I am fairly confident its something to do with the SC but just odd it still makes that much noise even with the belt cut off. And for it to suddenly start has me really confused.

Forrest Gump 9

My SC made some noise after a throttle swap. I open the throttle body plate and spray some wd40 in and that stop the noise. But it was a clanking noise, not like your. Good luck with you car.

GT-ER

Good luck with that...lol. I've tried that before and couldn't stop it for the life of me.