Pretty simple question, I just recently re-isntalled my turbos with all new gaskets from mazda except for the downpipe gasket. I thought it looked alright and I didnt really have the money to spend on a new one.

So last night I started up my FD and there seemed to be no exhaust leaks, but after 30 seconds lots of smoke started pouring out of the engine bay, from what looks like around the downpipe.

So basically my question is, can I re-use the downpipe gasket?, should I add some sort of a high temp sealent on both sides? Im assuming its not working because of all the heat cycling it went through before, but I dont have quite enough for a new one.

 

Is it a metal gasket? Are there any bends on the metal gasket that might mess up the sealing?

I use copper spray just to ensure it's stickiness

 

I've had no problems re-using the metal gaskets so long as their condition is good. I, too, use the copper spray on them during assembly. (Don't reuse them if they're severely eroded or starting to split.)

 

Yep, one of those layered metal gaskets. Seemed to be pretty straight and not coming apart.

This copper spray, can I just go to my local auto parts store and ask for a high temp copper gasket spray? Or is there a specific brand?

 

Eh, just slap it on there, get some grade 8 bolts, and tighten that guy realll good and you'll be fine.

 

When I reused mine I cleaned it off really good making sure there was no carbon build up on it with a wire brush. Then I used alcohol pads to clean it off before reapplying. To get that much smoke you would have to have a pretty big break in the seal tho.

 

Yeah, I will take it off and inspect then let you guys know. Maybe I overlooked something.

 

You can basically get the copper spray from any auto parts store, it's made by Permatex.
http://www.permatex.com/products/Aut...ve_Sealant.htm

 

Grade 8 is not a metric bolt designation. With the very high EGTs on an FD, Home Depot hardware is not the way to go. Mazda OEM is best here. There are many threads on this topic.

 

^
2nd

 

Why does it have to be Metric? It's just two holes and get the bolt as big as the hole will go. If it was something that bolted into the motor that would be one thing, but just bolting a downpipe to a mid-pipe/Cat I don't see why it matters. I ran it for a couple years with no problem.

There are many things I make sure is "authentic" or "Mazda OEM", but Exhaust bolts is Def. not not of them.

EDIT: Oh ok, I thought he was talking about the rest of the exhaust, not the actual downpipe to engine. Yeah I would do some sort of OEM or harder core order online bolt for that.