Hi there, I am back again with a question. Over the past few days, I have begun to realize that my Mazda likes to shake any bolt loose.

With that said, I noticed the exhaust got louder. First thought was the cat rusted threw. That's not the case. The exhaust manifold fell off. So I am wondering how exactly would I go about talking the heat shielding off and fixing the exhaust manifold. Also what bolt sizes should they be?

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Thanks, once more.

 

The 4 or 5 bolts that attach the heat shroud onto the exhaust manifold are a 12mm headed bolt......about 3/4" long. Use a 6 point 12mm socket if you have one......a 12 point may round off the hex shape, since those bolts are a little rusty on their heads. I know there is one (can't see it in your pic, but you can see 3 of the other ones) directly behind the exhaust manifold......it also holds that wire bracket for the O2 sensor wire (in your pic).

 

Alright, thanks. Hopefully this is will be the only time I'll have to remove the heat shield due to the bolts backing out.

 

I'm in Arizona, so mine came off readily.

 

Thankfully the heat shield came off with ease. On inspection it seems the nuts fell off. It seems they are M8x1.25 would this be correct?

 

Looks like someone forgot to tighten them......after a head gasket job, more than likely.

 

I doubt that.. however if they only tightened them once and didn't do a heat cycle then tighten them again. That I would believe.

 

The exhaust manifold studs had washers, as well as nuts.......they were just a thin flat steel washer.....as shown in this pic.