Corroded Muffler Bolts

[Carerra]

2010 C2S 108K miles

 

I was planning to replace the plugs.  I went to remove the mufflers.  They were very corroded - especially the two I do not have to remove.  I used penetrating oil (acetone + AFT).  They are much prettier, but they are still corroded.

 

Here is a 1 min video of the bolts so you can see what I am facing:

 

Questions:

If I get started on removing them and it does not go well, what next?  Surely I don't have to replace the catalytic converters?  Are the bolts somehow replaceable?

Do they look too far gone?

 

 

 

 

[JFP in PA]

Sometimes you have to cut the bolts away and press out or drill out the stubs and replace them.   Other times you can cut away just the nut and stave the studs.  When they really get nasty, like daily drivers in the Northeast with tons of salt on the road, you don't have a choice.  Some have taken to replacing them with stainless steel.

[Mike Robins]

I just completed a similar job. I used a ball joint separator to press the studs out. All 6 studs out in less than 10 minutes!

[Mike Robins]

I just completed a similar job. I used a ball joint separator to press the studs out. All 6 studs out in less than 10 minutes!

[Pepi]

Got same problem here, just one info to understand how to procede: headers flange are threaded? I mean, bolt are screwed into the flange or they just pass through?
Thanks

[Mike Robins]

Hi Pepi, the flange bolts on the header are NOT threaded in, they are press fit. Press them out with a press similar to the picture above. You can then replace them with M8x30 bolts. 

 

Mike

[Pepi]

Thanks for answer, but maybe i realized that you are talking about 997 but i got a 987, i believe in my case i have threaded flanges...

[JFP in PA]

3 minutes ago, Pepi said:

Thanks for answer, but maybe i realized that you are talking about 997 but i got a 987, i believe in my case i have threaded flanges...

 

I think yours are also pressed in...……...

[Pepi]

Well could be possible because the head if still very corroded seems to be round and not hexagonal...

[JFP in PA]

2 minutes ago, Pepi said:

Well could be possible because the head if still very corroded seems to be round and not hexagonal...

 

If they have button heads on one end like this, they are pressed in:

 

[Pepi]

Yes, maybe splines?

[Mike Robins]

Yes they are splined and pressed in. Shouldn't be any trouble using the ball joint separator. 

[Pepi]

Actually my troubles are about cutting nuts with dremel because they are corroded with hexagon lost...

[JFP in PA]

12 minutes ago, Pepi said:

Actually my troubles are about cutting nuts with dremel because they are corroded with hexagon lost...

 

Split the nuts with the Dremel, then press out the studs and you are good to install new ones.

[Pepi]

Yes thanks

[Carerra]

UPDATE - Started getting codes on the CAT.  Tried ignoring it, but it did not work.

 

I had to grind them off and put in new ones.  Now I have new codes.

[JFP in PA]

56 minutes ago, Carerra said:

UPDATE - Started getting codes on the CAT.  Tried ignoring it, but it did not work.

 

I had to grind them off and put in new ones.  Now I have new codes.

 

What codes?

[Carerra]

20 hours ago, JFP in PA said:

 

What codes?

Thanks for asking!   0010 and 0024

 

I posted it as a separate thread:  Renntech.org

[Desflurane 4u]

Late to the party but I had the same issue on my car.  Fortunately only one bolt broke.  If you can just put a socket on the bolt and attempt to loosen them till they break.  Then take an air chisel with a point tip on it and they will pop out in about 10 seconds.  You will have to take off the bumper cover so you can have a straight shot at the bolts.  Also makes changing the plugs and taking the mufflers off super easy with the bumper cover off.  I put up a video on YouTube and it only takes 10 minutes to remove the bumper cover. Don’t know why anyone would attempt a plug change without removing the bumper cover first.  Also these bolts are not available from Porsche as they are indeed splined. I went to every muffler shop in town and couldn’t get a replacement splined bolt.  Eventually bought a generic stainless steel bolt so I won’t have this problem again.