So, bad news obviously. Here is the situation.

Last weekend i changed the differential, transmission and engine oil (Redline 75w90 or whatever, MT90, GTX 5w20). I also used the mazda zoom engine cleaner. The 'ol shit, shower and shave for the RX8.

So all week it's been running better than ever. Very happy with the results of the above. So last night i park my car outside because we just resurfaced our garage and cannot park on it for a couple days. So it's outside in the elements (so sad) and it is starting to get colder at night, say 50.

So when i go outside in the morning i start my car. It's very rough and takes longer than normal. But i just assume it's because it's colder than usual. As it fires up i swear i heard a rattling noise coming from the engine bay, but i thought it was just in my head. Wait for it to warm up as usual, and head out on my way to work.

I'm just putting around, but i notice that every time i accellerate, even slightly, the car sounds different. There is this low grunt present that there didn't use to be. At the first opportunity i get to really accellerate i notice that it hesitates a bit and doen't quite give me the jolt i'm used to. So i'm worried but still think it's in my head.

I realized i forgot something at home so i turned around. When i'm at home i inspect the car and hear a distinct thud. It's completely sporatic and some times it was louder than others but nevertheless it was thudding. I put my hand over the exhaust and each thud the exhaust cuts out and then gives me a big puff.

Against my better judgement i drive into work. This time it's not just in my head, my car is gutless. Doesn't matter what speed or what gear i'm in there is a significant loss in power.

When i get to work i listen to the exhaust again and i notice that every thud i hear is followed by a metal on metal tingy rattling.

This cant be good. Any thoughts?

There's a theory that using the zoom cleaner could turn out bad if a large chunk of carbon got loosened up and was rattling around the the engine. It would be quite hard for anything that goes into the engine to leave thanks to the side ports.

That said I used zoom cleaner on my car as well.


Or the problem could be something not related to the maintenance you performed at all.

Usually the gutless comes from plug or coil issues. Not sure about the thud metal on metal sounds.

your cat may be clogged, thats why your exhaust puffs, metal rattling may be yout cat material rattling in the pipes

maybe its a good idea to stop using 5w20.

maybe its a good idea to stop using 5w20.

haha thats funny

maybe a bad/clogged cat

maybe its a good idea to stop using 5w20.

I have a case. I was uninformed when i bought it. One more change and no more 5w20.

Just dropped my car off at Mazda. Just from them observing the car running/revving they said there is definately a problem. We'll see.

haha thats funny

maybe a bad/clogged cat

FYI - i dont know if ^^ would cause a CEL but there was no CEL.

FYI - i dont know if ^^ would cause a CEL but there was no CEL.

many cats go bad with no cel.

beers :beer:

your cat may be clogged, thats why your exhaust puffs, metal rattling may be yout cat material rattling in the pipes

my guess too, the zoom cleaner might have finished off the cat. It's under warranty 8/80k

was the cat glowing red?

One more change and no more 5w20

kind of a touchy subject here, but 5w30 or heavier is basically the consensus I think.

if you didn't separate the cat from the exhaust manifold before the engine enema then you f'd up ....

engine enema, :lol:

take the cat off now and see how it drives.

yeah it sounds like a clogged cat also when doing the zoom/seafoam treatment it would fill up that cat with all that shi* and f*CK it up

so should one unbolt the cat and blow al that crap out or what?