What does it sound like: split secondary muffler
02-01-2011, 04:05 PM
#1
Rennlist Member
Thread Starter
What does it sound like: split secondary muffler
A new noise from the engine bay developed the other day...
Just the other day I started to heard a faint, tinny noise develop. At first I was worried it was coming from the valves or that the engine was laboring, but the noise increased and decreased with the engine RPM in such a way I now believe it's coming from the exhaust system. I've looked under the car and everything is solid and appears to be in place (no muffler joints have shifted).
Maybe my secondary muffler has split?
I have a primary bypass, but stock cat and 2ndary.
Observations so far:
I'll do a closer inspection of the car tonight to confirm any loose exhaust fittings, but can anyone confirm what a blown secondary sounds like?
I'm heading to the track this weekend, if it's a blown 2ndary, should I be concerned...
I found this tread on the topic:
from this thread: https://rennlist.com/forums/showthre...ferrerid=19642
(BTW: I'm a big fan of the primary bypass sound, so I'd rather fix/replace secondary)
Just the other day I started to heard a faint, tinny noise develop. At first I was worried it was coming from the valves or that the engine was laboring, but the noise increased and decreased with the engine RPM in such a way I now believe it's coming from the exhaust system. I've looked under the car and everything is solid and appears to be in place (no muffler joints have shifted).
Maybe my secondary muffler has split?
I have a primary bypass, but stock cat and 2ndary.
Observations so far:
- at idle the car is about 10% louder (it like that part)
- under full throttle it's about 20% louder (I like it even more)
- for the first time, I hear exhaust drone @ 3,000RPM during part-throttle steady state cruising.
- very light tinny, clanging vibration during idle
- if I rev the car parallel to a wall, I can hear the noise coming from the rear passenger side of the car (at 2nd location). Louder and louder clanging noise until the engine RPM get to abut 3K and then I just hear a much louder that usual engine roar!
- all engine gauges are normal, engine power is great.
I'll do a closer inspection of the car tonight to confirm any loose exhaust fittings, but can anyone confirm what a blown secondary sounds like?
I'm heading to the track this weekend, if it's a blown 2ndary, should I be concerned...
I found this tread on the topic:
My secondary muffler has failed twice now and was wondering if any of you have had this problem. First one split open and I bought another used one on ebay. The second one had no cracks before installation. After one day on the track, the second one split in almost the same place. I am considering having it welded up and maybe put some reinforcement welds as well. The car is primarily a track car. I have a cat bypass and cup pipe so this is the only muffler on the car. The cracked muffler sounds terrible on the car. My track sessions are 20 minutes and after my 4th run of the day, I started hearing the familiar rattling vibration. When I got home, I took it off and discovered cracks on yet another muffler. Just wondering if this is a common failure.
(BTW: I'm a big fan of the primary bypass sound, so I'd rather fix/replace secondary)
02-01-2011, 04:12 PM
#2
Rennlist Member
I would take the time to remove the secondary muffler and have a good look, it does not take long, if it is split you will have time to get it welded, and you sure as hell do not want it to split wide open during your track day, could ruin all the fun.
02-01-2011, 05:47 PM
#3
Sounds like it to me, same thing happened mine (primary by pass as well at the time) after a track day.
Did not know what the sound was for a while I thought it was a couple of broken heads studs and the sound was the loose barrels/cylinders clapping together.
was glad when i found out it was just the exhaust.
You will have to take it off to get a good look as they seem to go on the inside edge.
I put the primary back on with a G-pipe but like the primary by-pass better.
I got one to replace it on e-bay but it was in very bad condition (probably like most second hand ones) so never even put it on the car, might look at getting mine welded.
So still looking for a good condition secondary if anyone is fitting a G-pipe or has one lying around their garage.
Here,s a pic of where mine went,
Did not know what the sound was for a while I thought it was a couple of broken heads studs and the sound was the loose barrels/cylinders clapping together.
was glad when i found out it was just the exhaust.You will have to take it off to get a good look as they seem to go on the inside edge.
I put the primary back on with a G-pipe but like the primary by-pass better.
I got one to replace it on e-bay but it was in very bad condition (probably like most second hand ones) so never even put it on the car, might look at getting mine welded.
So still looking for a good condition secondary if anyone is fitting a G-pipe or has one lying around their garage.
Here,s a pic of where mine went,
02-02-2011, 04:34 AM
#6
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Mine split just as "Crystal Cranks" image displays too. I removed it and welded it. As I'm no welder, I found it quite hard not to make "holes" with the weld, but somehow managed to fix it. Has been holding up over a year so far.
A new OEM muffler would set me back around $2000!
A new OEM muffler would set me back around $2000!
02-02-2011, 09:20 AM
#7
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I had a similar problem the just over a week ago...
I heard a faint noise whilst out with the car from the left hand side, which sounded like the exhaust was blowing slightly. By the time i got home it had turned into a roar.
I jacked my car up on the drive (whilst praying on one knee it wasnt a heat exchanger as first thought) and found a HUUGGGGGE hole in my decat pipe. Thankfully the cheapest part to replace, otherwise i would have invested in a full exhaust upgrade, but I have other work due this weekend which would have needed to be put off :S
I have a new decat (and the other one off) and I'm picking up the new gasket and bolts from my OPC today and fitting it in a few hours
Then off out for a celebratory drive
I heard a faint noise whilst out with the car from the left hand side, which sounded like the exhaust was blowing slightly. By the time i got home it had turned into a roar.
I jacked my car up on the drive (whilst praying on one knee it wasnt a heat exchanger as first thought) and found a HUUGGGGGE hole in my decat pipe. Thankfully the cheapest part to replace, otherwise i would have invested in a full exhaust upgrade, but I have other work due this weekend which would have needed to be put off :S
I have a new decat (and the other one off) and I'm picking up the new gasket and bolts from my OPC today and fitting it in a few hours
Then off out for a celebratory drive
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02-02-2011, 10:31 AM
#8
Rennlist Member
Thread Starter
Updated: loose cat bolt
Thanks for the feedback guys!
I got very lucky...not lucky because it was a cheap fix, but lucky because I found the problem right way without talking a bunch of parts off (per by usual newbie tech method - talking off parts that aren't part of the problem).
Loose cat bolt...and the easy one to get to at that. I have all the wheels off the car right now as I'm replacing the front rotors and checking out the whole braking system before my track event this weekend. So while waiting for penetrating oil to work it's magic on one of the stubborn 19mm caliper bolts had a look around the rear arches...secondary looked fine. Then went over to the driver's side started tapping around on the exhaust...right away I saw the loose bolt...yeah!
http://www.youtube.com/watch?v=saul888BabA
<iframe title="YouTube video player" class="youtube-player" type="text/html" width="480" height="390" src="http://www.youtube.com/embed/saul888BabA" frameborder="0" allowFullScreen></iframe>
I got very lucky...not lucky because it was a cheap fix, but lucky because I found the problem right way without talking a bunch of parts off (per by usual newbie tech method - talking off parts that aren't part of the problem).
Loose cat bolt...and the easy one to get to at that. I have all the wheels off the car right now as I'm replacing the front rotors and checking out the whole braking system before my track event this weekend. So while waiting for penetrating oil to work it's magic on one of the stubborn 19mm caliper bolts had a look around the rear arches...secondary looked fine. Then went over to the driver's side started tapping around on the exhaust...right away I saw the loose bolt...yeah!
http://www.youtube.com/watch?v=saul888BabA
<iframe title="YouTube video player" class="youtube-player" type="text/html" width="480" height="390" src="http://www.youtube.com/embed/saul888BabA" frameborder="0" allowFullScreen></iframe>
02-02-2011, 02:05 PM
#10
Hi TA12 if 911jeta does not want it I'll take it but the shipping to Ireland will probably be prohibitive, let my know if you can find out how much to ship to Ireland.
Thanks.
Thanks.
02-02-2011, 03:53 PM
#12
Nordschleife Master
And that, sir, is indeed a loose nut.
But fair warning: you should always seek out a factory-certified loose nut trained Porsche technician to verify your (otherwise hopelessly simplistic, ad hoc) 'analysis'.
He has the tools, the training, and the experience to assist and rectify your nearly every loose nut problem. You do not.
Well, maybe, this one time you did get lucky. Probably quite proud with yourself - aren't ya? For sure, you certainly Did find that loose nut.... this time...
...and as result probably put a trained, qualified Porsche loose nut technician out of work.
Now, then. Don't you feel ashamed about that?
(You heartless bastard!)
....
Right, then!
At the risk of ambush bludgeoning by some Factory-trained catalytic seal installer, you might want to remove and inspect that juncture's metal seal to see if any of it has been eroded by leaking exhaust gas.
They're fairly inexpensive, < $10.
02-04-2011, 12:38 PM
#13
Rennlist Member
Thread Starter
...Well, maybe, this one time you did get lucky. Probably quite proud with yourself - aren't ya? For sure, you certainly Did find that loose nut.... this time...
...and as result probably put a trained, qualified Porsche loose nut technician out of work.
Now, then. Don't you feel ashamed about that?
(You heartless bastard!)
...and as result probably put a trained, qualified Porsche loose nut technician out of work.
Now, then. Don't you feel ashamed about that?
(You heartless bastard!)
I was totally smug thinking I had an easy fix to my problem...obviously I had a loose cat bolt (maybe the others too, I didn't check... -20 points on master mech. test) and had to move on to the main task at hand, changing the rotors.
So I start the car up and head out to bed-in my new pads and rotors.
Oh no, the car seems a little loud....
I hear that clanging/rattling noise at lower RPMs...
Pull over to a gas station and get on the ground to inspect...
Go over to the secondary muffler and start pushing against it...
The rattling noise changes as I press against the 2ndry...
Immediately start thinking of PMing various Rennlister in an attempt to buy their old mufflers...
Heading to the track today for tomorrow's DE...will deal with it on Monday...
02-04-2011, 01:33 PM
#14
Rennlist Member
Check the pipe clamps.... you never know... Secondaries are indeed available so don't panic. OR it could be a heat shield layer that's come loose too...
02-07-2011, 11:51 AM
#15
Rennlist Member
Thread Starter
The weekend I put over 600 miles on the 964!
600 glorious miles with a primary exhaust bypass and a cracked secodary exhaust. Other that the rattling coming from the loose bolt on the secondary hanger bracket, it sounded pretty good!
When I got home I took the passenger's side rear wheel off and saw a completely loose secondary bracket bolt. I thought I had an easy fix on my hand...until I looked around found a sheared off hanger bolt and a huge rip along my secondary exhaust. Huge rip.
To further complicate matters one muffler bracket bolt was completely missing (see picture). So the secondary was held on only by the clamp attached to the primary bypass. Not good!
So I obviously need to find a used secondary, and the correct bolts to support the muffler bracket (and missing spacer for the top muffler bracket bolt).
Anyone have a spare 2ndary for cheap (shipping to 27516)?
My real concern at this time is that the bottom support bolt must have taken the weight load of the system until it finally sheared off...leaving me nothing to grab on to get it out. Looks like I've got to get a shop involved?!
Will post pictures from the wonderful track weekend later...met another Rennlister at the track! Good times!
600 glorious miles with a primary exhaust bypass and a cracked secodary exhaust. Other that the rattling coming from the loose bolt on the secondary hanger bracket, it sounded pretty good!
When I got home I took the passenger's side rear wheel off and saw a completely loose secondary bracket bolt. I thought I had an easy fix on my hand...until I looked around found a sheared off hanger bolt and a huge rip along my secondary exhaust. Huge rip.
To further complicate matters one muffler bracket bolt was completely missing (see picture). So the secondary was held on only by the clamp attached to the primary bypass. Not good!
So I obviously need to find a used secondary, and the correct bolts to support the muffler bracket (and missing spacer for the top muffler bracket bolt).
Anyone have a spare 2ndary for cheap (shipping to 27516)?
My real concern at this time is that the bottom support bolt must have taken the weight load of the system until it finally sheared off...leaving me nothing to grab on to get it out. Looks like I've got to get a shop involved?!
Will post pictures from the wonderful track weekend later...met another Rennlister at the track! Good times!