# Car is way too loud.



## papereater (Sep 16, 2016)

People,

1987 sunbird GT , orig owner. My car measures 87-90 decibels inside cab while driving around 55 mph. Muffler shop found no leaks in exhaust system. What could be the problem? I have the original padding/felt below carpet, dont think that would muffle sound much anyway, even though it is a bit old/packed down. 

Tips appreciated as always, people.


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## papereater (Sep 16, 2016)

Oh- has 222,000 miles on it, but I doubt that might matter.


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## Nealtw (Jun 22, 2017)

papereater said:


> Oh- has 222,000 miles on it, but I doubt that might matter.


Undercoated floor?


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## papereater (Sep 16, 2016)

Nealtw said:


> Undercoated floor?


I think so, but not 100% sure. I can check though, easy to do, with a light, and scrape with fingernail. If not, would you brush a thick coating under there, jack up the car, and brush on? I have spray, actually. Can waste the can on it. BTW, car never was like this say, 15 years ago.


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## SPS-1 (Oct 21, 2008)

papereater said:


> Muffler shop found no leaks in exhaust system. What could be the problem?


Apprentice technician maybe ?


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## Nealtw (Jun 22, 2017)

papereater said:


> I think so, but not 100% sure. I can check though, easy to do, with a light, and scrape with fingernail. If not, would you brush a thick coating under there, jack up the car, and brush on? I have spray, actually. Can waste the can on it. BTW, car never was like this say, 15 years ago.


Check for leaks at the exhaust manifold at the engine and where it connects to the exhaust pipe. Broken bolts?


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## HotRodx10 (Aug 24, 2017)

Hard to say without knowing what kind of noise it's making; rumble, banging, something else? Does it make noise when it's stopped or only when you're driving? Is it loud at idle or only when you rev the engine?


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## quatsch (Feb 4, 2021)

An exhaust leak should give you a headache or nausea.

If it's "white noise" (like a waterfall) it may be air going past some crack in the body.


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## de-nagorg (Feb 23, 2014)

There is supposed to be a gasket where the actual pipe mates to the manifold, and on all vehicles with 100,000+ miles it usually is damaged or burned out.

A decent muffler shop will be in the know about this, and find it easily. 

It can be loose bolt, burned " donut" , or even holes in the pipe somewhere.

The muffler might be burned out, after this many miles, A visual inspection by you will be my suggestion.

Get a pair of slip-joint pliers, adjust the jaws to the proper size, and squeeze gently along the entire piping.

If you find any soft spots, you need a new muffler shop.


ED


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## papereater (Sep 16, 2016)

Lots of good tips, thanks, people. yes, I replaced that donut with new a year ago but never happy with the result. There is still a leak there which I tried to seal up with high heat RTV sealant, with no success, it just kind of blew off. I bet that has to be the culprit. I will go back and maybe have them focus on that spot. Maybe have them drive the car even.


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## papereater (Sep 16, 2016)

it is especially loud whenever I accelerate, then it gets really loud.


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## huesmann (Aug 18, 2011)

Can you tell which part of the car (front, back) the noise comes from?


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## Fix'n it (Mar 12, 2012)

no leaks front to back = muffler and/or cat is bad. 

go to a different shop. and don't "listen" to what they tell you = have them "show" it to you.


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## de-nagorg (Feb 23, 2014)

papereater said:


> it is especially loud whenever I accelerate, then it gets really loud.



We have a winner.

Check your motor mounts for breakage.

If one is broken, your engine is twisting and causing the exhaust donut to move, ever so slightly, and letting the noise get louder especially at acceleration. 

Been there. 

Also, if you did not get the exhaust bolts tight enough when you replaced that donut, it could be a prime cause for a leak there.


ED


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## papereater (Sep 16, 2016)

huesmann said:


> Can you tell which part of the car (front, back) the noise comes from?


Definitely from the front, like right below my feet/pedals area.


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## papereater (Sep 16, 2016)

OK, lots to follow up on. Could take me a while, but I will let you all know what happens. Thanks.


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## huesmann (Aug 18, 2011)

Could be a rusting out cat, or header/midpipe.


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## raylo32 (Nov 25, 2006)

Did you try leaving your wife home? ;-)


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## papereater (Sep 16, 2016)

raylo32 said:


> Did you try leaving your wife home? ;-)


She has not riden in that old car in decades.....LOL . Says it is a junk. Funny, how a junk has now 222,000 miles on it, and original clutch, and working (cold) ac, and even working headlight "doors".


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## papereater (Sep 16, 2016)

huesmann said:


> Could be a rusting out cat, or header/midpipe.


I think we should focus on that donut as the most likely culprit. My work has just begun.


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## raylo32 (Nov 25, 2006)

Be careful and take your time. On a car that old the studs or bolts that hold the pipe to the manifold are probably a rusty mess. If you can't get those off then you might need to remove the exhaust manifold... whose bolts will also be a rusty mess. If you can't get those off then you'd need to pull the head. etc, etc... Just getting started is an understatement. Good luck.



papereater said:


> I think we should focus on that donut as the most likely culprit. My work has just begun.


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## b.rooster4321 (Apr 22, 2020)

Different shop


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## papereater (Sep 16, 2016)

Wow, so I took a leaf blower, duct taped it to the tail pipe and blew, and sprayed soapy water on the donut as well as the 8 nuts/studs holding the manifold to engine. I found 2 studs leaking with bubbles! The nuts were loose! No wonder. tested with the blower and they didnt leak anymore. There is one stud missing on 1st cylinder far right, bottom. I should chase down a new stud, not sure what size (?). 

But, bad news is the donut also showed bubbles and when I crawled underneath to tighten the 2 nuts to the studs they were already maxed out (bottomed out) so I could not tighten that anymore than what it was. I should mention (not sure if i did already) that I recently put on a new donut and new studs, so no problem with old rusty studs/nuts, but im at bottom anyway. I think the 2 flanged surfaces are worn. How can I seal up this donut? 

I have little trust in a shop.


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## de-nagorg (Feb 23, 2014)

papereater said:


> Wow, so I took a leaf blower, duct taped it to the tail pipe and blew, and sprayed soapy water on the donut as well as the 8 nuts/studs holding the manifold to engine. I found 2 studs leaking with bubbles! The nuts were loose! No wonder. tested with the blower and they didnt leak anymore. There is one stud missing on 1st cylinder far right, bottom. I should chase down a new stud, not sure what size (?).
> 
> But, bad news is the donut also showed bubbles and when I crawled underneath to tighten the 2 nuts to the studs they were already maxed out (bottomed out) so I could not tighten that anymore than what it was. I should mention (not sure if i did already) that I recently put on a new donut and new studs, so no problem with old rusty studs/nuts, but im at bottom anyway. I think the 2 flanged surfaces are worn. How can I seal up this donut?
> 
> I have little trust in a shop.


 Donut is burned out. No sealing possible.

Check the pipe and manifold surfaces for wear also, sometimes a leaky donut allows them to burn too, and vice-versa. 

Unique way to pressurize a system, GOOD JOB. 

There should have been washers on those studs between the nuts and the flange to add a little extra space for tightening.


ED


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## papereater (Sep 16, 2016)

de-nagorg said:


> Donut is burned out. No sealing possible.
> 
> Check the pipe and manifold surfaces for wear also, sometimes a leaky donut allows them to burn too, and vice-versa.
> 
> ...


But donut is new (say, 1 year old). I mentioned it above. Thats why I am perplexed. I think the sealing surfaces that touch both sides of the donut are worn/burnt. RTV sealant didnt work a while back. I have not given up. Otherwise, would have dumped this car decades ago......LOL.


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## papereater (Sep 16, 2016)

Maybe a BIGGER donut, say, from another car. But which one...........


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## de-nagorg (Feb 23, 2014)

papereater said:


> Maybe a BIGGER donut, say, from another car. But which one...........


The donut is a fire resistant material fused to a steel ring.

In the OLD DAYS, it was asbestos, but now something different.

Any direct HOT EXHAUST ( flame) blowing by it will burn that material up, hence my statement that it has burned out, it takes very little time for a loose exhaust pipe to burn those out.

I am with you 100% on driving them forever.

I drove one for 26 years until 6 years ago, and a BLOND on the phone hit me, and the bodywork cost so much that it was retired permanently. 

I had $$$ tied up in those eventual repairs that driving one long time needs, but I did not get anything but joy out of keeping it going. 

Anyway, inspect the donut, it's surfaces for wear, and replace whatever is needed.

And keep on, keepin on.

ED


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## raylo32 (Nov 25, 2006)

If you are going to hang onto this car just replace all those parts... pipes flanges gaskets, etc. and be done with it. Unless you like to keep redoing the job over and over.


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## papereater (Sep 16, 2016)

raylo32 said:


> If you are going to hang onto this car just replace all those parts... pipes flanges gaskets, etc. and be done with it. Unless you like to keep redoing the job over and over.


Right, Ray, no sign of me abandoning this car yet. Will try to fix all to best possible condition. As you probably can guess, finding parts is almost impossible for these unwanted cars.


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## huesmann (Aug 18, 2011)

If any of the donut's mating surfaces were rusty, odds are it wouldn't seal right.


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## papereater (Sep 16, 2016)

What happens if you drop a steel washer into the exhaust pipe and cant fish it out with a wire?


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## HotRodx10 (Aug 24, 2017)

papereater said:


> What happens if you drop a steel washer into the exhaust pipe and cant fish it out with a wire?


Nothing. It just stays in the pipe until it rusts away.


papereater said:


> But, bad news is the donut also showed bubbles and when I crawled underneath to tighten the 2 nuts to the studs they were already maxed out (bottomed out) so I could not tighten that anymore than what it was.


If thet're the ones I'm thinking of, they typically have springs around the studs and the nuts are tightened against the springs. If it was assembled without the springs, it won't seal; it will leak and burn the donut gasket and the iron it's supposed to seal against.


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## de-nagorg (Feb 23, 2014)

I went looking for J. C. Whitney, for Sunbird parts.

Seems that in 2010 They were bought by Carparts. com.

And have no exhaust parts for a Sunbird.

R. I. P. , J. C. Whitney. You were a good goto for decades.


ED


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## de-nagorg (Feb 23, 2014)

papereater said:


> What happens if you drop a steel washer into the exhaust pipe and cant fish it out with a wire?



It will rattle and roll around, gradually wearing the pipe from the inside.

Might get lodged in the CAT, or the muffler.


They make a magnetic pickup tool on a flexible shaft, that should reach the washer and grab it.

ED


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## b.rooster4321 (Apr 22, 2020)

Look up the part for a caviler it might be easier to find


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## papereater (Sep 16, 2016)

Thanks again, people. Will report back when its all done.


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