Rattling Exhaust Mount

[viprez586]

Okay so I have the Megan Racing DP, Cat-Delete, and Cat-back. I like this exhaust so no im not getting a different one. Problem is where the Cat-back crosses over to the passenger side and passes under the Differential and control arm(?). It smacks both spots if you wiggle it back and forth. Now my picky little knock sensor picks it up as well as an annoying rattle under deceleration.
So for a temporary fix i took some silicone couplers and put them on the exhaust and clamped them down. One melted, the other fell off(probably melted too).

Wondering if anyone has some kind of foam or thick insulation wrap i can put around a 3-6 inch section.
So far what i was thinking of doing is taking some DEI downpipe insulation wraping it once, putting a section of large diameter heater hose over that, and wraping it again with some more heat wrap.

 

[absolute_DSM]

putting couplers on your exhaust doesnt make you any faster.



Heat wrap it like you said. No more rattle.

 

[viprez586]

And putting couplers on your exhaust doesnt make you any faster.

They dampened the rattle to stop/help phantom knock. Does phantom knock make your car slow?

 

[bling5tatus]

Haha, yes phantom knock will retard timing. You said it rattles and "knocks" under decel. Knocking under boost is where you run into major problems if it's too much/too long. Is the car knocking under acceleration?

 

[oldman]

Re-adjust your hangers.

 

[viprez586]

Haha, yes phantom knock will retard timing. You said it rattles and "knocks" under decel. Knocking under boost is where you run into major problems if it's too much/too long. Is the car knocking under acceleration?

When you accel it knocks sometimes it depends how much everything is flexing. when i deaccel you can hear it rub up againist it and it'll count as knock.
Even if i give it quick revs in neutral i'll get PH.

Not to get too off topic here but i revved it to 6k in neutral to see if it'd do it in high rpm and my car kind of lunged forward maybe like half a foot, im thinking maybe its time to replace my motor mounts?

Re-adjust your hangers.

What like get new/shorter/stiffer ones?

I guess it'd be good for people to chime in that have the same exhaust setup and see if they've had similar issues or what they did to fix it. My muffler can be shoved side-to-side quite a bit but not excessive that its going to fall off the hangers.

 

[jtmcinder]

I'm surprised that no-one has suggested muffler bearings yet.

- Jtoby

ps. excellent come-back on phantom knock making the car slow

 

[oldman]

My muffler can be shoved side-to-side quite a bit but not excessive that its going to fall off the hangers.

I don't have the same system as you but this is common exhaust sense that applies to all systems. If the it's touching sitting still, you need to bend the hangers around. If it has excessive side to side or up and down play causing it to touch on decel, you need shorter or stiffer rubber pieces between the chassis and the hangers that will produce less play. Take it to any exhaust shop and that is what would be done. Putting on any cushioning material is just a temporary fix because it will eventually worn itself out.

 

[Defiant]

Holy crap. Give any non-chain muffler shop twenty bucks to mount your exhaust so it fits.

 

[viprez586]

Holy crap. Give any non-chain muffler shop twenty bucks to mount your exhaust so it fits.

No thanks I'm enrolled in school to become a technician, so once I have undercar I will do it myself. Some mechanics don't take their job serious and will hack jobs just to get things out quicker. Others will take your car for a joy ride. Last time I took my car to a mechanic I started driving home and it wouldn't build any boost, pull over and the UICP isn't even connected.

Besides that have you seen some welders at muffler shops? They don't care how it looks just that it doesn't leak when it comes to welding.

I'd rather do it myself so I know its done right and the way I want it. My thread was for the reason of the fact that someone else might have this problem now or later in the future.

Thanks for changing the title.

 

[Street Surgeon]

Just crawl under the car and check a few things. If the rubber exhaust mounts are shot you can either replace them with new units or upgrade to the polyurethane hangers. You could also bend the actual steel hangers that go into the rubber hangers by bending them and such. All in all this is a very minor fix you should be good to go with a lil' elbow grease.

 

[viprez586]

Just crawl under the car and check a few things. If the rubber exhaust mounts are shot you can either replace them with new units or upgrade to the polyurethane hangers. You could also bend the actual steel hangers that go into the rubber hangers by bending them and such. All in all this is a very minor fix you should be good to go with a lil' elbow grease.

Good call , I looked at the mounts and yeah their stretched a tad. I ordered two pair because some of them are still good. On Ebay they said theyre "80% stronger then stock". Which I don't know is entirely true but since they're polyurethane It should be a lot better.
Just wondering if you have these or if anyone else has had experience with them?

 

[1bad92awd]

Just re-bend the hangers for your exhaust. Pop it out of the little rubber coupler under the rear bumper and see if you can just bend it a little bit to help adjust. That is where I would start.

 

[DSM Jeff]

Tweaking exhaust hangers is pretty common regardless of what company it is (for the most part) get your car up on jack stands or a lift and look at the metal hangers. Get a small torch and pliers or vise grips. Figure out which hanger may need to be moved over and in which direction. Remove the rubber hanger and then head up the steel and bend it using your pliers. Let cool, and get the rubber hanger back on. Do this until your exhaust sits correctly. I spent an hour and a half on a RnR exhaust, tweaking hangers until it cleared and that was on a lift (which give you a lot more space). Also replacing rubber should help as well.

 

[viprez586]

I had my undercar class today, bent some hangers a little bit, used those polyurethane hangers and fixed my downpipe hanger. I now have a 1/2" clearance between the Diff. + the control arm as opposed to resting on the differential. So problem fixed!
Thanks for your input guys!