FAQ: Supercharger Noise (Bad Coupler)

OK, I'm back from more acceleration tests, Bwaaahaahaahaaa

Rick, sounds like you have exactly the same grinding noise for the first few minutes of warmup that I do. And I "felt up" my coupler when I was changing pulleys and it has zero slop.

I first heard this noise the day after I gutted the AB lid, so that's what the red thing is for (besides screwing up the IAT sensor...) It could be the sealed bearings in the intake side of the blower, or maybe just the sound that the rotors make until they swell up and seal better. Either way, I wouldn't worry about it. You probably just noticed yours when you did because it was spinning a different pitch with the new pulley.

...and since we've completely pirated this thread, I'm happy to report good news at my "test strip" today. I chose a different lane than I did before, and it was also dry & warmer all day. With the Traction Control turned off, and letting the car idle with the brake off for about a car length before hammering it, I pulled a solid 7 seconds today... (Okay, 7.05 seconds, but all my previous runs have consistently been 7.5 to 7.8)

GMFreak8 wrote:

I went redneck on it and superglued the hoses to the battery, just in case. Seems to work great though.

Well if you don't have the original rubber strap with the rectangle-to-round-pipe fittings, gluing it was probably a good idea. You might want to hit it with silicone or yellow snot, something that can fill & seal better than crazy glue... Be sure to mark your calendar to check back under there in a month for any signs of leakage!

Rick, I only had that growl at startup after I removed the stock airbox and put in my FWI. The loss of the OEM flexy tube thingy with the muffler in it I believe was the cause. When I reverted back to the stock airbox the cold engine growling went away. That noise also went away after the car warmed up.

The GenV supercharger swap seems to have eliminated that growl too!

Well, I'm still running the gutted airbox with a flat K&N filter.
And this noise is louder than anything I heard prior to doing the rockers and 3.4 pulley.
Has gotten louder as the temps drop, so I'm considering it just to be the tolerances in the SC when cold.
As I mentioned before, the loud SC noise goes away after a few minutes of warm up, and before the coolant gets warm.
So I'm not worried about it. I'm sure it would be even louder with a cone filter hanging off the intake.

After having gutted my airbox last year, I am wanting to re-install they grey resonating chamber to reduce or hopefully eliminate the noise I hear from the SC after starting it up cold and it lasts for 2 or 3 minutes.
It's a disturbing noise and anyone listening will think and has mentioned that there is something wrong with the engine.
I'm hoping that putting that grey plastic thing back in will eliminate the noise.
It sounds like the SC needs overhaul for the first few minutes, then it goes away. Presumably as the rotors heat up, expand and seal inside the case.

Rickw wrote:

After having gutted my airbox last year, I am wanting to re-install they grey resonating chamber to reduce or hopefully eliminate the noise I hear from the SC after starting it up cold and it lasts for 2 or 3 minutes.
It's a disturbing noise and anyone listening will think and has mentioned that there is something wrong with the engine.
I'm hoping that putting that grey plastic thing back in will eliminate the noise.
It sounds like the SC needs overhaul for the first few minutes, then it goes away. Presumably as the rotors heat up, expand and seal inside the case.

Your basic premise is correct... And you'll please notice that I've always said, as in my signature, that the only thing that needs removal is the red restrictor in the air box LID... The resonating chambers in the air tube or the bottom of the air cleaner are not going to hurt air flow at all.

Okay... been tracking down the newest demon... (I also have my ABS and TC light on all of a sudden...yeah!)

Recently noticed S/C at idle, or low RPM is making sort of a hissing noise... a deep hissing noise. I've replaced the coupler, and the second time I took the snout off (to reseal the snout) the s/c pulled almost all the way out... pushed it back in and it turns by hand just fine.

Now at idle it sounds like a low hiss...almost the same sound as water right before it boils on a stove...that hiss sound...

But at speed, sounds fine...

Vacuum problem?

Anyone encounter this before?

Thanks!
N

Vacuum leaks are generally associated with a rough running engine, even just an uneven idle could be a vacuum leak.

How does the car feel and drive.?

Have you tried using a mechanics stethascope to listen at all different locations around the engine compartment to try and pinpoint an area, if not the specific spot.
Mechanic stethoscopes are available at the parts stores and Sears for around $10.00 and are real handy to have in your toolbox.

I disconnected the s/c belt and the sound isn't there. It's coming from the s/c

Moderator, why would you move me to this thread? My car isn't making a rattle in a can noise... I replaced the s/c coupler (it used to rattle in a can)....

I had a new topic and I don't think you should have moved it... I don't want to be buried in 9 pages of replies to a totally different problem....

Well, I'm glad you were able to generalize the noise to the SC.
I still think it would be a wise and inexpensive investment to buy and use a stethoscope to find the exact location of the noise and hopefully be able to seal it up or repair what you find.
Once you have the tool, you will find you use it more often than you think, especially driving an older car.
I've never heard the noise, and it doesn't go away once the car is warmed up, correct.
Or do you think the reason you can't hear while driving at speeds is because of the normal wind noise's are masking it.
Maybe someone else has had this problem and can step in and tell you were to look more specifically than I can

One other thing, have you hooked up a vacuum gauge to read manifold vacuum at idle. If so, what is it reading and more importantly is the reading steady - no needle bouncing around.

Natesriv wrote:

. I've replaced the coupler, and the second time I took the snout off (to reseal the snout) the s/c pulled almost all the way out... pushed it back in and it turns by hand just fine.

Thanks!
N

Are you saying that the rotor pulled out of the s/c case?

And if so, did the new noise start right after?
(Not to panic, but I"m wondering about the needle bearings...)

Curiosity killed the cat..................................even though i was being blamed for a while.

But, yes is it possible that enough needle bearing juice came out and is causing some noise.
No way to know without pulling it all apart and lubing them with the correct Eaton grease.
Also, would be nice to hear this noise in person. The hissing before the water boils does not sound like a needle bearing noise to me.
But I don't know how the noises can travel through this aluminum housing and become distorted.

well, I listened closer, it's A LITTLE like a rattle...
Yes the noise started after the s/c came out of the snout... It sure sounds like it's coming from the gears on the front (pulley side) by the two big gears .....

What needle bearings? Did I do damage?...Did something come out that shouldn't???

Any way to fix?

Thanks gang!

Natesriv wrote:

well, I listened closer, it's A LITTLE like a rattle...

Yes the noise started after the s/c came out of the snout... It sure sounds like it's coming from the gears on the front (pulley side) by the two big gears....

What needle bearings? Did I do damage?

The needle bearings support the "other end" of rotors (TB side.)



If the noise is coming from the snout side, though, that is probably not it... and I doubt that you could have hurt the ball-bearings on that side. Perhaps you put a little scratch on the inside of the rotor case, and that is making a whistling/whirring sound?

There is a good set of photos of the supercharger parts here:
http://www.thrashercharged.com/tech_htm/blower_tear.shtm
.

I think I'll pull the snout again... I can't imagine what it would be, but I have to see what's in there...
It has plenty of oil and that's fresh, and the coupler is brand new....

I'm stumped but I gotta fix it..sounds like a hiss/rattle all the time..

Nate,
Do me a favor and try and take some detailed photo's of everything you can see.
Especially if you are going to pull the rotors and look for any nicks or issues that might be causing the noise.
Thanks,
Rick

I can do that...

The new coupler is on tight, so tight that when I opened the snout again (to reseal a leak) the entire innards came out too..had to pry bar the snout a little to get it to pop open (there's an indent on the snout you can pry at)

It'll be next week or later I suppose...I'm not afraid to drive it, but it probably is best I don't until I know for sure...

then it's to Menieke to figure out why I have an ABS/TC light on.

How does one replace those needle bearings in the case?

Albertj

albertj wrote:

How does one replace those needle bearings in the case?

Albertj

I try not to think about that...

Would require a blind hole bearing puller.
Not a slide hammer type, but a type that will go in and grab the back end of the needle bearing cage and through tightening the puller in a steady manner it will pull those out.
Now I'm assuming they were installed correctly, which left a small area behind them to grab with the split collett from the bearing tool.

I have a shop manual...so I need to look at the exploded view of the impellers for the S/C

But when they slid out with the snout, I was able to push them back in and they seemed to spin just fine.

Pulling the impellers out didn't "pop" a bearing out...or otherwise they'd crash into each other.

I'm going to have to dig into it again and see what's what...

All this talk of pulling the snout, and yet not 1 mention of the proper Anaerobic sealant that's required when you put it back on......
And I also didn't read that you refilled the snout with oil after you pulled it? Maybe it's dumb, but no oil on those gears would "hiss"......

No I put oil in it...LOL...and it's still full...no leaking

It's full and I sealed the snout with red gasket sealer...

Natesriv wrote:

No I put oil in it...LOL...and it's still full...no leaking

It's full and I sealed the snout with red gasket sealer...

Just making sure. We've all had "those" moments lol.

Abaddon wrote:

All this talk of pulling the snout, and yet not 1 mention of the proper Anaerobic sealant that's required when you put it back on......
And I also didn't read that you refilled the snout with oil after you pulled it? Maybe it's dumb, but no oil on those gears would "hiss"......

I believe we did tell Nate about the Anaerobic Gasket Maker for the flange when he did it the first time.
And I assumed when he mentioned the Red Sealer this time, he was referring to the Anaerobic Sealer.
Also Nate, when you plan to open this up again I wouldn't hesitate to re-use the the Synthetic fluid again provided you have a clean syringe to remove it with and a clean container to put it in.
BUT, if you find anything out of place or rubbing, or abnormal in the supercharger or if the color of the fluid has changed from when you put it in then I would throw that fluid away for fear of contamination. And start looking very closely for the source of contamination. Possible aluminum.
So I guess it would be best to have some new fluid on hand if you need it, and if you determine it is not necessary to change it you can keep the fluid on the shelf for the next scheduled fluid change.
Also, if you have run out, get a tube of Anaerobic Gasket Maker. I find the Permatex brand at my local parts store to be in stock at all times.

Natesriv wrote:

well, I listened closer, it's A LITTLE like a rattle...
Yes the noise started after the s/c came out of the snout... It sure sounds like it's coming from the gears on the front (pulley side) by the two big gears .....

The SC snout pulled the Rotor Assembly slightly out of the housing with the Rotors attached during a coupler change.?
Is this correct.?
And then you were able to separate the two and slide the Rotors back into the housing and then get on with replacing the coupler, Correct.?
Have you purchased an inexpensive Stethoscope yet.
You will need it to help you pin-point where this noise is coming from.
You may swear that it is from the SC Snout area but find out differently with a stethoscope.
I and many others have mis-diagnosed noises before.
Noises can be the hardest thing to diag on an engine.
Check all rotating components on the front (passenger side) of the engine. Including the usual suspects, pulleys and tensioners, water pump, power steering pump, etc.
The fact that you had to un-tension the belt to do the job in the first place and then re-tension after can cause problems with another component that possibly had week bearings, etc.
I'm grabbing at straws, but none of these tests take much time and will give you piece of mind.
You said you de-tensioned the SC Belt and the noise went away. What else is driven off that belt.?