Rusty Nuts - Premuff and Dansk

[JeremyD]

I took my valence off and Bumper bumpers. Got most of the bolts for the heat shield on the Cat off.

The main ones on the muffler and cat are definitely there from 1987 - good and rusty - couldn't budge them - didn't try too hard as it was getting late.

Put some liquid penetrant on them and let them sit. Anybody have any ideas as the best way to get them off?

I have a dremel - and am not afraid to cut 'em off - I don't have a torch - but those are pretty easy to acquire. Anything else?

I'd take them to a muffler shop - but I'd like to do it myself. Not cheap just determined.

Thanks in advance - and yes, I did a search first

[cstreit]

Ace hardware sells a small MappGass/Oxy setup that would work... Cheap too.

Jeremy,
I used a torch with Mapp gas. It took a while to get the nuts red hot, but once there, they came loose pretty easily. Good luck.

[cary]

DREMEL ...............let er rip. Anything else is a waste of time.
They aren't worth saving.
But remember to use plenty of cooper based anti seize when you put them back together. Be sure you rubber gloves. The anti-seize is messy.

Good Luck

[scottb]

PB Blaster is the penetrant of choice. I replaced the muffler on my 84, and first soaked the nuts in Blaster overnight. They came off VERY easily.

You can bet PB Blaster at most auto parts stores. I got mine at Pep Boys.

[KTL]

If the PB B'laster (highly recommended) doesn't work then just cut 'em off. The muffler & cat flanges aren't threaded so once you sever them, they'll slip right out. Well maybe a little coaxing with a hammer and screwdriver, but they'll come out easily once you cut 'em. You're not gonna want to save them, so why bother unscrewing them?

Wil Ferch always recommends replacing them with silicon bronze SAE (1/2" size) nuts and bolts to avoid corrosion in the future. The si-br stuff has high copper content which is much more resistant to corrosion than the cad plated stuff. The factory cadmium plated stuff starts to rust really quick. I don't drive my car much more than 2000-3000 miles/yr. and after one year my metric cad plated stuff looked pretty bad on the inside.

Since 1/2" and 13mm are so close and are pretty much interchangeable as far as tools are concerned, I like Wil's recommendation (although i've yet to get the si-br stuff yet). The si-br stuff I know of is full threaded (@McMaster-Carr), but I don't think that really matters much for the exhaust stuff?

[Doug Zielke]

PB Blaster is the best penetrating oil on the market, but the oxy-ace torch makes short work of the most stubborn nuts. Just showing them the blue flame has them begging for mercy!

[cstreit]

Doug,

I always called it "The Big Blue Wrench"

What is it with anti-seize anyway. I'll get a bit on my hand and next thing you know I'm covered in the stuff. Gets everywhere in 5 min flat!

[cary]

Just to second Kevin's comments. When I've taken them off. I've replaced the nuts with BMW hardware. Probably the material that Kevin's taking about.
The nuts look like the ones on the hubs of a kids bike.

Just my .02c.

[Doug Zielke]

[cary]

Chris, I don't get it either. You need like a TVEK jump suit to work with that stuff. But it works.

[350HP930]

Hey Jeremy, just let me know if you need a second set of experienced hands to help you with your project.

I would be happy to assist.

[JeremyD]

Thanks Tony if I get at an impasse I'll give you a buzz - I have success so far - Have all the bolts off - Just muffler straps now which should be easy -

Only thing that is not budging is my o2 sensor. Any ideas/suggestions?

[scottb]

Same advice...hit it with some PB Blaster, and wait overnight. Also, you might consider getting the socket for the O-2 sensor, and using a long cheater bar. There was a thread on the Board very recently about someone trying to get a rusted O-2 sensor out. It was not a pretty picture. Go slow, and good luck!

[JeremyD]

Any cross reference on the 02 sensor or is it a Porsche only part?

[Wil Ferch]

KTL:
Thanks for remembering my bolting suggestions. Here it is again:
5/16" x 18 pitch, 1.5" long under head, partially threaded 316 Stainless bolts.
Matching nuts are Si /Br ( Silicon Bronze). These have 1/2" heads and work with 12 or13 mm wrenches. Very close dimensionally to stock 8mm x 40 mm long regular steel bolts.
---Wil Ferch

[SteveStromberg]

Here is the Bosch and Factory #'s

0258003162
96560612601
Oxygen Sensor
91-94

0 258 003 162
96460612401
Oxygen Sensor
89-90

[JeremyD]

Thanks Steve - after some liberal dousing of PB Blaster and some gorilla kama sutra leverage positions I was able to break the O2 sensor free.

After that it was smooth sailing - got it all back together in about a hour. I'd crank her up tonight but afraid I would wake the kids... and the neighbors!

[cicsprog]

We will here you comin at the next Pelicanite get-to-geather. Nice work!
Now I know someone who can replace of O2 sensor and will work for beers!

Jason
88 911

[JeremyD]

Actually just a nice rumble - Now she sounds a little more like my old C2 (which I like) - I like the dual tips too. burble burble burble!