Exhaust Manifold Gaskets
 

When should you not reuse them? Or should you just get new ones after 1xx,xx miles?

ive reused ones before that were in good condition, but it really depends on how the look once you get the manifold off. But at the same time the likely hood that an exhaust leak will form is greater.

One of my original gaskets was actually missing part of the inner lip so I obtained a "new" used one from a friend but the one he sent has a small crack on the inner lip as well. Should I scrap that one also?

The shop manuel recommends changing them when you pull off the manifold. Due to the high price of these, it forces people to re-use them. I was fortunate to find a brand new set someone was selling on e-bay for $50. I get a discount on Mazda parts at the local dealer. I can check into them for you or, you can give Ray at Mallory Mazda a call (sorry, don't know the # off the top of my head).

Here's a couple of pics of the gaskets. The first pic is my original (cleaned) with part of the inner lip missing and the second pic is the new one with a small crack indicated by the pick tool.

I would'nt use that (2nd one). I'm sure I have a set of used but good condition ones, will look for them and let you know.

Thanks.

PM'd thread starter. I have a good condition set. Let me know if you're interested.

Most times, you can re-use them. It's just one of those things you don't want to have to tear back into it if you have an exhaust leak.

The stainless gaskets Mazda uses are VERY hardy, and can be re-used many times. They usually fail if you have the bolts/nuts/studs that hold the flange together come loose and create a gap - this will blow the gasket out in short order.

Dale

Well, what causes them to crack like the ones posted above?

I'm not sure how much the OEM replacements go for but, you can get them from www.mazdatrix.com for about $76 per housing.