Twisted off exhaust manifold bolts

[sammcgee]

Fixing up winter Festiva.
Have exhaust leak in front of cat.
took downpipe off....twisted off studs that connect to manifold.
took manifold off and got studs out...they're threaded....tough job.
Will a parts store have replacement studs or should I just install bolts? What would you guys do?

thanks ....sam

What does the gasket look like between the cat and downpipe. Is it a donut-like looking unit?

[Pu241]

Re: Twisted off exhaust manifold bolts

Will a parts store have replacement studs or should I just install bolts? What would you guys do?

If you can use bolts I would, just make sure you match the thread type.
I think its 10mm x 1.25, but could very well be wrong, please check!
If possible use stainless steel with ant-seize!
Not sure parts store will care studs/all thread in metric sizes but can check with a Fasenal store they generally can order anything!

What does the gasket look like between the cat and downpipe. Is it a donut-like looking unit?

Yes, it is a metallic donut, but generally unless they are really badly damaged I've never had to replace it. just have to make sure the down-pipe and cat clamping contraption is making a good seal with the gasket!

[sammcgee]

ok....picked up some bolts at the hardware....10x1.50 is what the parts man told me but when I tried them they seemed a skosh big....wouldn't thread up...so I think I'll clean them up with a tap and try again. anti-seize is good idea.

the reason I asked about the gasket is that I thought it would just be a small unit that would just fall out when the downpipe came off. I need to drop the cat and get a better look at it. That's where all the noise is coming from.

thanks...........sam

[Pu241]

ok....picked up some bolts at the hardware....10x1.50 is what the parts man told me but when I tried them they seemed a skosh big....wouldn't thread up...so I think I'll clean them up with a tap and try again. anti-seize is good idea.

Yeah, chase them and see if they aren't the right ones because now that I think about it, you would want course thread for a manifold application!
remember with anti-seize you don't want to over torque the bolts due to lubrication of threads.

..the reason I asked about the gasket is that I thought it would just be a small unit that would just fall out when the down-pipe came off. I need to drop the cat and get a better look at it. That's where all the noise is coming from.

Are you sure its the front side of the cat?
Because generally exhaust noise from front of cat is from failed down pipe cracked lengthwise or flange to the front of the cat has cracked or broke. Noise from behind Cat is usually failed gasket between cat and Mid-pipe or failed gasket between Mid-pipe and muffler or failed muffler.

[sammcgee]

yes I think it's in front of the cat.....looks like an attempted cobble fix from the previous owner....will drop it and take a closer look.

[Pu241]

yes I think it's in front of the cat.....looks like an attempted cobble fix from the previous owner....will drop it and take a closer look.

Yeah, then you likely correct!
Just hope they hadn't completely fu...mbled it up!
With luck the cat gasket surface is intact or can be fixed hopefully same with down-pipe flange and gasket surface!

Hey pics would be helpful if you got or can get some!

[sammcgee]

I used a 3/8ths tap to clean them up.....went back and got some 3/8ths bolts.....little sloppy.
bought a 10 x 1.5 tap....cleaned them up and original bolts work perfect.
tonight she goes back together.