Loud noise in rear when going over bumps?

M

myblkgt02

New Member

Jun 6, 2005

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Deland, FL

Oct 20, 2005

#1

• Oct 20, 2005

• #1

One of the first mods I did was a Magnaflow exhaust that I installed myself. Now I hear a loud 'bang' when I go over a bump. It appears to be coming from the left rear. I've checked the clearance of the entire exhaust system and all looks very good. So, any thoughts?

Thanks

 

hotrodnut

Member

Jul 12, 2004

672

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North Florida

Oct 20, 2005

#2

• Oct 20, 2005

• #2

If it didn't do it before the exhaust install and it did after, then it's probably to do with it. When you are looking at the exhaust clearance is the suspension loaded? Can you get someone to push the car up and down while you look at it? The upper control arms will in a sence, get shorter and longer as the suspension travels up and down and at static height appear not to have a clearance problem. Although when the suspension is compressed it will pull the control arm into the over the rear exhaust pipe.

 

FORCED2DV8

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Jun 6, 2005

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Grand Rapids MI

Oct 20, 2005

#3

• Oct 20, 2005

• #3

Check all your exhuast hangers, and then also the clearance when it at ride height,

 

C

Chopper1

New Member

Jan 2, 2005

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Wv

Oct 20, 2005

#4

• Oct 20, 2005

• #4

hotrodnut said:

If it didn't do it before the exhaust install and it did after, then it's probably to do with it. When you are looking at the exhaust clearance is the suspension loaded? Can you get someone to push the car up and down while you look at it? The upper control arms will in a sence, get shorter and longer as the suspension travels up and down and at static height appear not to have a clearance problem. Although when the suspension is compressed it will pull the control arm into the over the rear exhaust pipe.

Click to expand...

Agree,and look around the gas tank too.When the rear end hits the pipe it could be banging into the gas tank.Ther ain't much room under there for bigger exhausts.

 

M

myblkgt02

New Member

Jun 6, 2005

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Deland, FL

Oct 20, 2005

#5

• Oct 20, 2005

• #5

hotrodnut said:

If it didn't do it before the exhaust install and it did after, then it's probably to do with it. When you are looking at the exhaust clearance is the suspension loaded? Can you get someone to push the car up and down while you look at it? The upper control arms will in a sence, get shorter and longer as the suspension travels up and down and at static height appear not to have a clearance problem. Although when the suspension is compressed it will pull the control arm into the over the rear exhaust pipe.

Click to expand...

Thanks, hotrodnut, I think this exactly what I need to look into. I installed the exhaust using ramps, so it was at static height. I'll get one of my buddies to help diagnose the suspension.

 

M

myblkgt02

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Jun 6, 2005

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Deland, FL

Oct 20, 2005

#6

• Oct 20, 2005

• #6

FORCED2DV8 said:

Check all your exhuast hangers, and then also the clearance when it at ride height,

Click to expand...

Speaking of exhaust hangers, what is the best way to get the hanger out of the rubber insulator?

 

T

tradde

New Member

Aug 2, 2005

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Pennsylvania

Oct 20, 2005

#7

• Oct 20, 2005

• #7

I sprayed a bit of WD-40 on the hanger, and it made the rubber part come
off much easier. A screwdriver may help too. Just don't tear or damage
the rubber hanger.

 

M

myblkgt02

New Member

Jun 6, 2005

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Deland, FL

Oct 20, 2005

#8

• Oct 20, 2005

• #8

Good old WD! Thanks for reminding me!

 

helty

some Ukrainian's enjoying a handjob via my credit

Mar 30, 2005

1,461

1

39

Baltimore, MD

Oct 20, 2005

#9

• Oct 20, 2005

• #9

same thing happened to me. the over-axle tuning was rubbing the under carriage wheneve i pulled out in first gear. 2 minute fix.

 

M

myblkgt02

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Jun 6, 2005

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Deland, FL

Oct 20, 2005

#10

• Oct 20, 2005

• #10

helty said:

same thing happened to me. the over-axle tuning was rubbing the under carriage wheneve i pulled out in first gear. 2 minute fix.

Click to expand...

What exactly was your 2 minute fix?

 

TrueBlue03

Member

Dec 9, 2003

372

3

18

Bay Area, CA

Oct 20, 2005

#11

• Oct 20, 2005

• #11

my magnapack catback clunks over every single bump i run over because it sits against the rear sway bar (i have eibach sportlines tho )

 

0

'03GTinFLA

Member

May 29, 2004

486

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St. Petersburg, FL

Oct 20, 2005

#12

• Oct 20, 2005

• #12

I had the exhaust tips hitting the hangers. Tightened them up, good for a week then started again. Used Lock-tight and fixed for good. Don't know how the magnaflow catback tips are, mine were just the magnaflow tips.

 

helty

some Ukrainian's enjoying a handjob via my credit

Mar 30, 2005

1,461

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39

Baltimore, MD

Oct 20, 2005

#13

• Oct 20, 2005

• #13

myblkgt02 said:

What exactly was your 2 minute fix?

Click to expand...

well, i have the SLP modular cat-back, so all i had to do was crawl under the car, loosen a band-clamp, re-position the section of tubing that was rubbing, and re-torque the band-clamp. problem solved.

im pretty sure the magnapack system uses band-clamps as well, just not sure about the regular magnaflow cat-back.

 

G

GNN60GT500

Founding Member

Jun 18, 2002

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5 car lengths in front of you!

Oct 20, 2005

#14

• Oct 20, 2005

• #14

Most common reason for this is the pipes are hitting the gas tank-

Loosen up the system, take one hand and push the pipe away from the gas tank while at the same time tightening the system back up with your other hand-

will take care of the problem and should not take more then a few minutes-

 

M

myblkgt02

New Member

Jun 6, 2005

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Deland, FL

Oct 20, 2005

#15

• Oct 20, 2005

• #15

My exhaust is the Magnaflow Cat-back Exhaust for '99-04 GT with 4x9x14" Muffler, 2.5" Tubing, Rear Exit, 3.5" Tip. It connects with U-bolts.

Thanks for all your advice and comments. I am going to take a good hard look at my alignment and clearance tonight and will report back tomorrow on my findings and hopefully good news - that being no more banging!

 

helty

some Ukrainian's enjoying a handjob via my credit

Mar 30, 2005

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Baltimore, MD

Oct 20, 2005

#16

• Oct 20, 2005

• #16

good luck man. like i said, look really good at the over-axle tubes, and like the guy above you said, the gas tank as well. even if you dont see anything touching, if theres any part of the tubing thats pretty close to anything, try to adjust it out of the way as much as you can then take it for a test spin.

the biggest pita for me afterwards was trying to get my exhaust tips lined up again.

 

M

myblkgt02

New Member

Jun 6, 2005

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Deland, FL

Oct 21, 2005

#17

• Oct 21, 2005

• #17

Problem Solved

Good news to report, after checking the exhaust clearance at static height and while pushing down on the truck, I found the problem: it was the left tailpipe hitting the rear sway bar. I also found that the left extension pipe was really jammed into the muffler, so once I corrected that issue, the alignment going towards the tips more or less fell into place. And as helty said, aligning the tips is a pita!

Thanks to all for your help!

 

jasonh_86

I

May 20, 2005

1,156

2

48

Arkansas

Oct 21, 2005

#18

• Oct 21, 2005

• #18

after i had my catback off, I never thought i was gonna get my tips back straight

 

Jackie Chan

I didn't read this.

Founding Member

Oct 17, 2002

2,507

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48

Orlando, FL

Oct 21, 2005

#19

• Oct 21, 2005

• #19

magnaflows sound better with dumps anyway...ditch the tailpipes