Exhaust Bolt sizes for 997.2 C2

[raykelly]

I did an inspection under my car last week during the oil change and spotted that the Exhaust Bolts are badly corroded :-(
I need to change my plugs and these babies have to be changed. Do not know how I am going to get them off. I have sprayed wd40 on them, hoping it will help when I go to take them off. (i doubt it). In fact I sprayed every bolt underneath with wd40 ;-) .

Anyone got any 'cutting exhaust bolts' tips?

Anyway, I want to replace with stainless steel bolts. I found out they were M8 40mm (hope thats right) but I need to know the diameter of them. Anyone any ideas? They're are the bolts that connect the side mufflers to the centre muffler at the rear. Three on each side.

Also, anyone know the best place to shop for these? Or maybe some place that sells them as a set, that would be really helpful?

thanks!

 

[Ianstewartshouse1]

M8 should mean the bolt is 8mm diameter Ray.

Depending on access if the WD doesn't work, you can use physical force up to 8mm or so to break the bolt so that would be my first choice if you are replacing (as long as there is a bolt and separat nut i.e. nut is not tacked to back of flange) I have done this before on bolt/nuts up to 10mm But you need ring spanners as open end spanners may just strip if nut/ bolt already corroded. Just do the same as you would to loosen but but force until it snaps bolt

If if that doesn't work you are into territory of a mini grinder or hacksaw depending on space available.

Others may have better ideas as I have not yet attempted to remove these particular bolts

TR fasteners do them (A4 and 316 are compatible)
https://www.trfastenings.com/products/Catalogue/Screws-and-Bolts/Hexagon-Screws-and-Bolts/Set-Screws?material=72

And all metal Stainless self locking nuts

https://www.trfastenings.com/Products/Catalogue/Nuts/All-Metal-Self-Locking/Binx?material=120

Ian

 

[raykelly]

Hey thanks Ian, shows my knowledge of bolts obvious now!

yeah was thinking the grinder was the option albeit a little dangerous. I have access to an air saw but think the compressor i have now is not powerful enough.

hey for your xpipe, did it come with stainless steel bolts? If so could you send a pic of bolts?

Cheers!

 

[raykelly]

Ha nice one, im only seeing the links at bottom now! Using my mobile so page didnt load correctly. Thanks again!

 

[angusc]

You might like to research this a little more before taking the plunge to disturb those corroded nuts and Studs!!

It is a common issue with older cars (older than 6-8 years) and you are likely to shear at least 2-3 of them and then you will need to drill out the broken studs from the cylinder heads and then have to re tap and helicoil to fix the threads. It all depends how confident you are to be able to manage that task yourself at home.......

 

[Ianstewartshouse1]

Hi Angus, I think Ray means the 3 bolt flange on the manifold (cat) to primary silencer.

heres the best photo I can send ( not at home) the new ones with my kit seem to be dip coated 8.8 not stainless l'll see if my mrs can take a more detailed pic later

I have a good selection of stainless screws and nuts which I might use although I will need some hi temp all metal lock nuts!

 

[angusc]

OK cool......yes I think your right so they should not be too bad to cut off or shear off and replace.

 

[raykelly]

Yeah thats the bolts I was on about Ian.
Thankfully its not the bolts in the head, phew! I wouldn't touch them. Although i have checked the manifold ones and they are in good condition. I still gave them a spray of wd40 last week.

Ian that pic is perfect. The links you sent helped. I will order some tonight.

Thanks!

 

[raykelly]

So I've ordered some A4 M8 Stainless Steel bolts and Nuts from here. They will stand the heat better than the A2 Stainless steel. I will keep an eye on them to see if they hold up to the task.

I found another sight that provided a great selection of bolts etc... cheap too. However, they don't deliver to Northern Ireland. !! Here is their website.

 

[Ianstewartshouse1]

Yes Ray A4 is the same as 316 stainless as I said above so either or is ok I think.

Thanks for the web address I think I'll order some up!

 

[raykelly]

You know what, I was nearly going to say to you, did you want any. But then thought you might have your own wee stash they were dear enough As postage was half the cost almost. I got the serated flanged hex nuts and flanged hex bolts 40mm. I ordered 8, 2 for spare. Im going to dip mine in ACF-50 I have too. No need to but it will give that little bit more protection.

Next time I will say to you. Cut down on postage.

 

[Ianstewartshouse1]

Yea I have some ordinary SS nuts and bolts but was going to go for the flanged and self locking type. My replacement ones are 30MM did you measure your OE ones at 40MM?

 

[raykelly]

No didn't measure them. Im in Romania this week! So my baby is at home, sorry I mean car. Seen it in a forum somewhere and thought that it might be too much but a little bit extra is better than too short. So didn't want to take the chance. Can always cut them to length if it's really bad looking. I hope!

 

[rich mich]

I done this on my 987 boxster last march ,used a air die grinder and a dremel ,managed to grind off some of the captive bolts caps and knocked them through with a pin punch,refitted using m8 copper coated steel bolts and nuts,as ss will weaken overtime due to heat and cooling (I could have tried applying heat with a map gas torch to manifold and tapped them out but I did not have any gas) Porsche wanted £500 to do job,done all six took about 4 hours, checked the ones on my 981 they are starting to corrode,only 2 on each exhaust on the 981,car has Porsche warranty on so I will speak to them when service is due in may.

 

[raykelly]

Tidy tidy job. Very nice!
I will give the ss ones a go now as they are on their way to me. If they fail, copper will be on my shopping list! Mine are in such a mess.
Is something like this under warranty?
£500 wow! Just a £100/hour for them

I will have to cut mine off too as I don't have access to gas.

 

[Ianstewartshouse1]

Split the difference and went for 35MM!

Good info here Ray if you haven't seen it
http://rennlist.com/forum...t-install-997-2-a.html

 

[raykelly]

Good idea
Great Link!I will be saving that one.
There was a lot of rusty bits under his car looking at the photos for the miles it had!

 

[raykelly]

Right, bolts changed but what a pain. Took many hours messing around. Had to order new fastners for the back box that sits behind the bumper. As the bolts were almost gone. So car will be up on stands until Wednesday now, waiting for those to arrive. Have spark plugs to change too. The new bolts are much better and theyre covered in copper grease too. Every bit helps.