'04 Chevy Colorado
Ext Cab
Z71
4x4
3.5L I-5 engine
2.5" exhaust (I believe)

Had a Flowmaster (Delta 40 I believe) installed about 5 years ago and apparently something inside of it is falling apart (rattling/screeching noises; Tommy looked at it and said it's the muffler). Any suggestions on a new muffler? I don't care for super loud or annoying, but I like a little rumble . And I'll just assume that everyone would agree to go to Bob's to have it installed.

5/26/2010 12:02:55 PM

You sure it's not the cat?

5/26/2010 3:27:56 PM

I've seen a muffler die from the outside (rust or a puncture), but never heard of the guts of a muffler falling apart before... it's usually just pieces of metal welded together with different chambers.

Here's the inside of a flowmaster:



Your 40 series was probably the loudest out of the bunch. 50 series and 70 series are "quieter" from what I've heard.

[Edited on May 26, 2010 at 3:46 PM. Reason : ...]

5/26/2010 3:41:37 PM

I meant something like a baffle wall coming unwelded. And I can't be sure. All I know is that Tommy (Mission Valley 66) was pretty sure it was the muffler

5/26/2010 3:47:05 PM

I love the sound of Borla exhausts. Produces just the right "rumble" you're looking for. Go Youtube some videos, you'll agree.

Pricier than flowmaster, but worth it IMO.

[Edited on May 26, 2010 at 4:12 PM. Reason : $]

5/26/2010 4:12:00 PM

could be some of the cat broke and worked its way to the muffler

5/26/2010 4:46:34 PM

could be a crackhead got hold of the wrong stuff

5/26/2010 4:53:32 PM

Ima rent a backho and uproot dat tree

5/26/2010 4:56:05 PM

to me it look like you got a leprechaun in yo muffler to me

5/26/2010 4:57:13 PM

5/26/2010 5:01:02 PM

Really though, I suspect this might be a cat issue. Is the muffler easily removable, or is it welded on?

5/26/2010 5:02:53 PM

welded. how am I going to figure out which one it is? I've had two shops say they think it's the muffler; though if something broke off in the cat and entered the muffler...

[Edited on May 26, 2010 at 5:12 PM. Reason : .]

5/26/2010 5:11:29 PM

I have a 50 Series Delta Flow on a 3.0l V-6 and freakin' love it. Little bit of rumble on the outside, but I can't hear shit from the inside of my truck.

5/26/2010 11:08:31 PM

is the whole thing welded solid, or are there a couple pieces to the system?

5/26/2010 11:12:12 PM

the exhaust system? AFAIK it's all welded. I can look later

5/27/2010 6:22:01 AM

guy at work had some flowmaster 40s do the same thign

5/27/2010 7:16:31 AM

update:

1.) There is a broken support for the exhaust pipe; though I don't think it's causing any of the noises; maybe it put some extra strain on another support though... I'll see if Bob's can weld in a new support.

2.) If I push up on the exhaust pipe/muffler, there is a loud popping from what seems like is inside the muffler, right at the intake. Wiggling these parts also makes a squeak/chirp. I suspect these two noises are what I'm hearing (around 1300-1500 RPM), but much louder.

So what would make that noise in the muffler? If I shake it, there is no banging (like a loose part in the muffler), but if I push up on it, there is a loud pop when I let it back down...

I'd like to just take it to Bob's.... but they seem more interested in just replacing parts instead of ensuring the problem is fixed.

[Edited on May 27, 2010 at 5:49 PM. Reason : .]

5/27/2010 5:48:26 PM

Get under the truck and get a good firm hold of that broken support and have someone rev the engine and see if it still does it.

5/27/2010 5:52:32 PM

but there's nothing to hold onto

I can see where a piece was attached to the frame, then I can see where a bar was welded to the tail pipe... just the remains are there. But I'll try holding another support while it's running.

so... If I just barely push on a support, the chirp/squeak goes away. However, I can't find any place that is rubbing, all the heat shields look fine, and it sounds like it's in the muffler to me.

ALSO, if I put just a pound, maybe two, of downward force and a bracket near the muffler, there is a lot of clanking/banging from what again, sounds to be from inside the muffler....

I'm hoping the guys at Bob's will work with me on this...

[Edited on May 27, 2010 at 6:08 PM. Reason : -]

5/27/2010 5:54:22 PM

^on the bracket... not and a bracket

5/27/2010 8:35:54 PM

Just be thankful you're only dealing with the muffler instead of the cat.

5/28/2010 12:03:10 AM

cut off exhaust
install whistle tips
....
profit

5/28/2010 8:27:17 AM

Surely the locals will not approve.

5/28/2010 9:09:04 AM

dats only in da mornin

5/28/2010 12:09:48 PM

Ah yes, when said locals should be preparing their morning victuals.

5/28/2010 12:39:35 PM

Weird, I though it was gonna be excessive movement/rubbing from the broken support, but the downward pressure thing screws that up. Looks like you're gonna need to put a new muffler on it.

5/28/2010 1:48:05 PM

UPDATE! Ended up getting a new muffler today.

Entire story in case anyone was wondering:

Summer 2005: Had new muffler installed (wanted one; no issues, other than stock sound with stock muffler)

March/April 2009: Metallic scraping/screeching sound coming from around muffler (message_topic.aspx?topic=564374)

June 2009: Went to Bob's to have it checked out; found that a stock support bar had broken off of the tailpipe, just before the muffler, so they welded a new one on. Scraping sound stopped.
(message_topic.aspx?topic=564374)

March/April 2010: Metallic scraping/screeching/chirping noise returns. Rattling noise also begins. I notice that if I push up on the tailpipe, just at the muffler intake, when I let the pipe back down, there is a loud pop right at the intake.

June 2010: Went to Majestic Muffler (Bob's was too busy). Put it up on the lift and we find that the muffler wall, on the intake side, is nearly completely loose (muffler welding was broken). Replaced muffler and added a much stronger support just before muffler.

Hypothesis: When the original stock support broke off, too much pressure was put on the muffler wall welds, that plus some rust weakened things enough for the wall to start to pry off. The support bar Bob's welded in temporarily stopped all noises by providing enough support. However, it wasn't enough for the long run and would allow too much flex in the tailpipe, leading to the deterioration of the rest of the welding on the muffler wall.

[Edited on June 11, 2010 at 5:28 PM. Reason : .]

6/11/2010 5:27:43 PM

shoulda gone to RJ's in Raleigh, competitive pricing, much better quality work and excellent service

6/11/2010 5:33:02 PM

I just had a mess of a time at RJs and will never recommend him to anyone.
He tried to chage me $400 more than the quote when I came to pick up my car.
His 3 day job took 7 days.
His exhaust work keeps developing a leak.
He said my car was poorly put together.

He had terrible pricing, quality TBD, and not so good service for me.

6/12/2010 11:25:34 AM

shit. what kind of custom shit did you get

6/12/2010 1:24:30 PM

There were multiple muffler threads, I picked this one, don't fight me

Anyways, I don't know much about this shit so needed to make sure I'm not getting ripped off. Brought my 08 Rav4 in to a mechanic for some check engine light stuff (rodent at some wires apparently), and mechanic also says I need a new muffler. Gave an estimate of around $750.

Being that this car just passed inspection a few months ago and they had no problem with the muffler (I assume they check that), does it make sense that I would have a problem now? And does that price make sense. When I google "Rav4 muffler replacement" I see a bunch of stuff for like a hundred bucks, but if I Google, "how much to replace a Rav4 muffler" I get shit that says $500- $1200. Anyways, here's a picture the mechanic sent of the muffler

2/12/2018 4:10:55 PM

Check out the local junkyards. That'd be my first thought.

2/12/2018 4:55:01 PM

Seems a bit steep to me.

Here is a diagram of your exhaust


http://www.rockauto.com/en/moreinfo.php?pk=3483465&cc=1441511&jsn=9

Part 280-605 is $90 and can be bolted on pretty easily. It has a slip joint on the front (left side) to part 096-1673 which is apparently the Catalytic converter. That part is $165.

Prolly a good bet to get gaskets for both ends too, so throw on another $20 and you are at $280 in parts, and thats without any discounts or shopping around.


If the car isn't any louder than it normally is, I would keep on rockin and start stashing a bit of cash to fix it down the road.

If you don't particulary care 100% about keeping it stock or whatever, just take it to Henry's muffler or equivalent and get them to throw something on.

2/12/2018 5:40:03 PM

i'd run that piece of shit until i couldn't stand the sound or i couldn't find an inspection station to pass it. fuck it.

2/12/2018 7:34:05 PM

What about carbon monoxide leaking into the car if there are holes?

2/12/2018 8:45:49 PM

not likely, but if you get a headache, crack a window

[Edited on February 12, 2018 at 9:09 PM. Reason : serious: you're traveling forward. there's wind and such. it's not gonna make it in the cabin.]

2/12/2018 9:08:46 PM

1. Unless you are stationary for long periods of time, CO will not be an issue
2. I wouldn't touch it unless you can't pass the state inspection.
3. The mechanic may be technically correct as yours is showing some signs of [likely] damage; but he's trying to sell you something, so there's that. He's not dishonest, but he isn't completely forthcoming; assuming there is nothing wrong beyond whats in your photos.
4. Bout tree fiddy to fi hunned, depending on the selected muffler and shop for replacement.
5. Nice thread.

2/13/2018 7:57:08 AM

Thanks for the input everyone. My concern on the CO is mostly for my 1 and 3 year old and a wife who worries about that kind of stuff.

I think at a minimum it's safe to say I should bring it somewhere else and get a second opinion, if not forget about it for now

2/13/2018 10:30:32 AM

there are millions of folks driving around with exhaust leaks, many of them much worse than that. have you ever heard of anyone dying from CO in the cabin from such a leak?

2/13/2018 7:00:44 PM

^yeah one of the guys from that west virginia mtv reality show and couple of his friends

2/13/2018 8:38:51 PM

well shit

2/13/2018 8:40:57 PM

This thread bump is good timing. Apparently my exhaust pipe is spit apart between the CAT and muffler. My inspection is due this month and this truck is an old beater. I really don't like throwing money at it when it's otherwise unnecessary. Hoping for a $200 pipe replacement, but am worried it's all rusted to shit and will need a complete exhaust system replacement.

Or... do auto shops normally look under a vehicle during a state safety inspection (emission inspection exempt)? I was getting an oil change / inspection and that's when the mech noticed the broken pipe. Just wondering if I take it to a typical mechanic for an inspection only, will they still look underneath?

[Edited on February 14, 2018 at 12:43 PM. Reason : .]

2/14/2018 12:43:07 PM

if it's a short straight section, I've had that kind of crap done for $20-40. Took the guy under 10 minutes, including getting the car lifted

2/14/2018 1:28:52 PM

$130 for the whole shebang. Do it

~$50 shipping

[Edited on February 14, 2018 at 1:33 PM. Reason : Do it]

2/14/2018 1:31:31 PM

thanks, but different truck

1995 F150 V8 with custom dual exhaust. don't remember any specifics beyond that; nor have I looked at the split pipe (yet).

[Edited on February 14, 2018 at 1:43 PM. Reason : .]

2/14/2018 1:41:38 PM

Henry's muffler shop gave me a complete new exhaust system between the cat and the muffler for $110.

2/14/2018 2:29:52 PM

^i'm hoping for the same. going to henry's later today

IDGAF he duct tapes it and passes teh inspection. that's all I want (the inspection).

[Edited on February 15, 2018 at 1:25 PM. Reason : add another note]

2/15/2018 1:24:15 PM

w00t. $50 and I'm good to go. cut out /replaced the section between muffler and cat.

2/20/2018 7:39:35 AM

also, yes my truck is much quieter

not sure how I didn't notice that it had gotten louder.

2/28/2018 8:36:40 AM

When he did my exhaust work the resonator he installed was significantly larger than the one he removed. Made the exhaust way too quiet for my tastes

2/28/2018 11:08:08 AM