Hi guys - started digging into my SA yesterday and not surprisingly started finding issue right away.

1) I am assuming that I shouldn't have open cooling lines here, right? Picture was taken laying on the ground looking up at the oil cooler. Red arrow points to the open fittings. What is supposed to go there?



2) My car has a bad backfire when I lift off the throttle, and while I know this is not uncommon this is pretty excessive. This looks off to me and likely letting in extra air, could I get your coaching on this please?









Thanks in advance for the help.

 

1. are the cooler lines for the a/t cooler. most aftermarket radiators come with them, that way there is 1 part number to do every car. if yours is an m/t then they are just left open.

2. that pipe doesn't look good, i'd pull it off and look further

 

OK, my car is a m/t so no worries on cooling pipes then. Thanks.

Agree that pipe looks nasty. What exhaust routing is that specifically for?

Thanks for the help.

 

not sure, the thing that looks like a catalytic converter in the middle of the car, is a heat exchanger, it takes the air pump air and heats it up, and then injects it into the thermal reactor.

that pipe looks to be either the pipe to or from the heat exchanger, i don't know which is which

 

What's crazy is that's how Mazda shipped these things back then. That's probably a high-temp (asbestos?) shielding which surrounds a metal pipe that comes from the heating catalyst to the front of the thermal reactor and is switched by the air control valve on the lower intake manifold.

You are correct that these tend to get banged up, holes rust through, and let cool air into the exhaust at the front and heating catalyst which will definitely cause heavy backfire. When mine had a hole in it, flames would occasionally shoot out the muffler with backfire sounding like a 12ga shotgun. You'll need a new bypass air pipe if yours is damaged unless you can find a welder to work on it.

 

Great info, thanks.

 

Good morning - I am going to bring the car in to an exhaust fabricator today or tomorrow. Is it correct that I am asking him to patch any holes / replace the pipe in the same diameter and then re-wrap it?

Anything this else I need to be aware of?

Thanks!

 

make sure your guy understands how much heat these RE exhausts generate so he uses a proper grade of pipe. Otherwise you will be having the same problem sooner than later.

Stu Aull
80GS
Alaska

 

Thanks Stu. As it turns out I do not have an exhaust leak, so it is looking like my Air Control Valve.