Has anyone encountered exhaust rattling after installing engine mounts? [SOLVED]

[StraightOuttaCanadaEh]

Very embarrassing rattle coming from the back of the car, intensifying with revs and for some reason much worse when the weather is warmer. Sounds like a rock rattling around in a cooking pot. I mentioned this to the mechanic after I picked up the car and he said with the stiffer mounts, rattling is expected. I’ll be going back after deciding I can’t drive around with the car sounding like a broken down POS.

Has anyone dealt with this issue? Do I need exhaust hangers/clamps, whatever? The exhaust is a Corsa and the mounts are updated Perrin items.

[NoHaveMSG]

If he jacked up the motor to squeeze the mounts out it may have shifted the exhaust around on it's hangers to the point it is touching somewhere.

I am on stiffer engine, trans, and diff mounts with no rattle.

[ActionMaxon]

Did your engine vibrate much before the new mounts?

Stiffer mounts could cause engine vibrations to harshen, however it would be felt in the body, especially steering wheel due to the proximity of the engine mounts and rack mounts.

If your engine is more "locked in place" that would mean your exhaust should be receiving less vibrations.

I agree with above. Sounds like an install problem.

I haven't worked on exhausts on this car but on, at least the later model subies, there was a tab on the exhaust near the catalytic converter that attached with a single 14mm bolt. The body side mount itself was designed in a way that you could undo the bolt and the exhaust would still hang there because the mount had a sort of catch. Horrible explanation I know.

Anyway, that bolt had to come out in addition to unbolting from the heads to lower the manifold any. Maybe that bolt was not reinstalled?

Possibly this is the case and you're hearing your exhaust bounce around on that mount? That would sound like it's right under you though so maybe not. Just a thought.

Maybe someone who has actually had the manifold/cats off these cars can say if this sounds familiar.

Other than that yeah, maybe something got tweaked or a bolt did not get tightened.

Can you shake the rear of the exhaust by hand and hear anything?

[StraightOuttaCanadaEh]

Originally Posted by NoHaveMSG

If he jacked up the motor to squeeze the mounts out it may have shifted the exhaust around on it's hangers to the point it is touching somewhere.

I am on stiffer engine, trans, and diff mounts with no rattle.

all he told me was that he had to remove the headers to do it. I also have the trans and diff mounts. Good to know! thanks

[StraightOuttaCanadaEh]

Originally Posted by ActionMaxon

Did your engine vibrate much before the new mounts?

nope

Stiffer mounts could cause engine vibrations to harshen, however it would be felt in the body, especially steering wheel due to the proximity of the engine mounts and rack mounts.

definitely vibrating a lot more with the new ones

If your engine is more "locked in place" that would mean your exhaust should be receiving less vibrations.

I agree with above. Sounds like an install problem.

I haven't worked on exhausts on this car but on, at least the later model subies, there was a tab on the exhaust near the catalytic converter that attached with a single 14mm bolt. The body side mount itself was designed in a way that you could undo the bolt and the exhaust would still hang there because the mount had a sort of catch. Horrible explanation I know.

Anyway, that bolt had to come out in addition to unbolting from the heads to lower the manifold any. Maybe that bolt was not reinstalled?

Possibly this is the case and you're hearing your exhaust bounce around on that mount? That would sound like it's right under you though so maybe not. Just a thought.

Maybe someone who has actually had the manifold/cats off these cars can say if this sounds familiar.

Other than that yeah, maybe something got tweaked or a bolt did not get tightened.

Can you shake the rear of the exhaust by hand and hear anything?

I'll check that, thanks for your reply. I'll try to rock it back and forth by the exhaust tip after work today

[NoHaveMSG]

Originally Posted by StraightOuttaCanadaEh

all he told me was that he had to remove the headers to do it. I also have the trans and diff mounts. Good to know! thanks

If it is coming from the rear, I would check where the catback routes under the subframe. If it is coming from the front check FP/OP clearance. I had issues with both these spots, had to loosen and shift stuff around to make sure it didn't touch. I also had clearance issues with my diffuser. So if you are running one check to see if the bottom of the muffler is hitting there. Mine does trap road debris(including part of a skunk) in there.

[StraightOuttaCanadaEh]

Originally Posted by NoHaveMSG

If it is coming from the rear, I would check where the catback routes under the subframe. If it is coming from the front check FP/OP clearance. I had issues with both these spots, had to loosen and shift stuff around to make sure it didn't touch. I also had clearance issues with my diffuser. So if you are running one check to see if the bottom of the muffler is hitting there. Mine does trap road debris(including part of a skunk) in there.

Nope, no diffuser or skunk, but what's weird is we had a bout of cold last week and there was no rattling. Now that temperatures are above freezing again, it's rattling like crazy.

And I don't know if this means anything, but sometimes it'll be a specific event that'll set off the rattling or make it worse at the very least. I'll go over a pothole or a bump in the road and all of a sudden the rattling is worse.

[StraightOuttaCanadaEh]

Originally Posted by ActionMaxon

Can you shake the rear of the exhaust by hand and hear anything?

So I grabbed the tips one by one and shaking them both produced that rattle

[ActionMaxon]

If you can make the rattle happen that way, bring it back to the shop, show them what you're talking about.

Shouldn't be too much trouble to get it taken care of. Seems like they caused it, but if they don't own up maybe they can help you out on cost on good faith.

[JBezugs]

Originally Posted by ActionMaxon

I haven't worked on exhausts on this car but on, at least the later model subies, there was a tab on the exhaust near the catalytic converter that attached with a single 14mm bolt. The body side mount itself was designed in a way that you could undo the bolt and the exhaust would still hang there because the mount had a sort of catch. Horrible explanation I know.

Anyway, that bolt had to come out in addition to unbolting from the heads to lower the manifold any. Maybe that bolt was not reinstalled?

Possibly this is the case and you're hearing your exhaust bounce around on that mount? That would sound like it's right under you though so maybe not. Just a thought.

So I’ve had an annoying exhaust “knocking” sound that would make noise when reversing and steering, or putting the e brake up when parking after driving the car that was coming from directly underneath the car (like the trans tunnel area). It happened right after I got my header installed and was exacerbated slightly when switching one of my exhaust hangers to an extended hanger to level my exhaust tips out. I went through the entire exhaust section and everything was tight.

My car is currently stored for the winter but I will be sure to take a look at this as soon as it’s back on the road in the spring. Thanks!

[ActionMaxon]

Originally Posted by JBezugs

So I’ve had an annoying exhaust “knocking” sound that would make noise when reversing and steering, or putting the e brake up when parking after driving the car that was coming from directly underneath the car (like the trans tunnel area). It happened right after I got my header installed and was exacerbated slightly when switching one of my exhaust hangers to an extended hanger to level my exhaust tips out. I went through the entire exhaust section and everything was tight.

My car is currently stored for the winter but I will be sure to take a look at this as soon as it’s back on the road in the spring. Thanks!

Looked at some repair info on exhaust today. According to Mitchell, these cars do utilize that exhaust mount point I was talking about. It's located at trans mount. Hope that helps you when you check it out.

[mav1178]

the front pipe is bolted to the transmission via a bracket, so most of the engine's movement is now transferred to the exhaust.

it may very well just be bad exhaust hangers, that's the easy fix. the hard fix is to replace your exhaust, the excessive vibration + temperature difference may be making the baffles inside rattle. but keep in mind that this is normal with harder engine mounts, the vibration is now transferred to the rest of the chassis.

[StraightOuttaCanadaEh]

Fixed the rattle today. Turns out it was a loose bolt at the front pipe/trans area just like a few of you said. Thanks guys!

[SuperTom]

Originally Posted by StraightOuttaCanadaEh

Fixed the rattle today. Turns out it was a loose bolt at the front pipe/trans area just like a few of you said. Thanks guys!

Yeah that bracket that connects the FP and Trans has 2 bolts connected to the trans. They can be loosened and adjusted a bit.


Glad you got it figured out rattles are the most annoying thing in the world.