Hey I'm new here, my name is Jesus and I have a little or maybe big problem. I have a 2004 rx8 4spd auto (yeah Ik it sucks) well a few weeks back as I was driving to my friends house, I wanted to have a little fun and at the same time give the engine it's daily redline to clean it off a little and as I started accelerating I noticed something rather strange. When the car hit about 80 mph and or like 6-7k rpm in 3rd gear. I noticed a huge loss of power, the car would accelerate really really slow and at the same time I heard some kind of grinding in the engine bay. So I immediately shifted to 4th gear and slowed down to reduce the rpm and that seemed to fix the noise. I started investigating the problem. Worried that my engine was kicking the tires, I decided to do a compression test and I got 120psi which is in good condition for a rotary. Next I decided to replace my spark plugs and also get an oil change. That kinda fixed the problem a little... At least for the first two days it seemed. Just last night as I was accelerating again at about 6-7k rpm the same engine grinding noise and the loss of power. Have any of you experienced something like this? Should I be worried about my engine or could it be something simple I missed to check?

Also forgot to mention I'm about to hit 130k miles on this baby.

 

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The grinding may be a fault in your auto tranny, you may want to have a Mazda tech have a look and see if any gears are grinding. Or you can look up a tutorial on how to do it yourself and save some $$$.

 

So you're saying I might need to get a new tranny?

 

No He is saying have it inspected.
When was the last time you replace your tranny and diffrentials fluid?
What fluid are you currently running?

 

It's been a while since I checked the transmission fluid. That's something I don't regularly pay attention to. I never connect loss of power with the transmission. Is there a diy on how to change the transmission fluid?

 

There are a ton of Trans fluid DIY's out there. Its literally two plugs (one drain, one fill) and a pump to get the new stuff in. Do some googling, should be able to find something with little effort.

Do rear-diff fluid at the same time. Exact same procedure, different fluid!