Hey everyone,

im a new member here, I own an 04 RX8 with approximately 134k miles. Recently I had an oil change, drove my car a bit afterwards when I started noticing a SERIOUS loss of power, particularly in 5th and 6th on the highway. It would act like it was struggling to accelerate and then it would grab and go. Could this be spark plugs or is this the sign of the dreaded apex seals blowing? I don’t exactly have 2k to spend on a rebuild.

the other issue is I just replaced the clutch master cylinder yesterday and now I have 0 pressure in the clutch pedal. My dad and I attempted to bleed it but no fluid was coming out. I’ve also ensure it’s not a broken bracket on the pedal. Is it possible there’s air trapped in the master cylinder itself?

 

Make sure you full the brake fluid reservoir completely. The clutch shares the back part and can empty if you don't notice.

The clutch hydraulics on this car are a PIA to bleed. Best us to use a power bleeder. Doing it by hand is a bit hit and miss...

 

we got the clutch to stiffen up some, it’s still not coming all the way back up on its own, but at least we have pressure now. The reservoir is totally full, just wondering if there’s still air trapped in the MC or possibly even the clutch itself?

 

If the car starts fine, especially when warm, its likely not an apex seal.

90% of the problems of a loss of power comes from bad coils and/or bad spark plugs. Replace those and your power should come back.

 

Oh thank god! I know just enough about rotary engines to be dangerous lol. I went down a rabbit hole on YouTube last night, everything on there was saying apex seals so naturally I freaked out. I guess that’s the equivalency of checking WebMD for a sore throat. We’ll see what happens with the plugs first.

 

I ran my renesis engine to 105,000 miles before I pulled it for a swap.

Never had an apex seal failure, but probably replaced the plugs and coils 5x to fix a low power issue.....To give you some perspective.

 

I changed the plugs, the problem is still there. Next step is to check the coils and replace the 02 sensor on the cat. I starts fine when the engine is cold, however once it’s up to operating temp, it runs rough. I noticed sometimes when I’d go to take off from a light, the RPM’s weren’t going up, it also felt like some pressure behind my pedal. The other possibility is a clogged cat.

I’ll let you know what I find out.

 

And if your coils are failing, the cat may not be far behind. That's what usually kills these engines. "apex seals" is what people who don't know anything about apex seals say about rotaries. If you haven't already, read rx8help.com, it should give you a foundation for owning and maintaining these cars.

How exactly is this power loss manifesting? Do rpms go up but not speed? Do rpms jump around? Is it always at the same rpm or always at the same speed? Full throttle only or partial throttle as well?

 

yeah, I’m leaning more towards coils and or cat being the culprit.

the power loss seems to come after the car is up to optimal operating temp. It’ll sound like it’s being bogged down, I’ll push the accelerator all the way down, it’ll act like it’s struggling to accelerate then will take off. While that’s happening the RPM’s stay the same, even if I drop down a gear. For instance if I’m in 4th going 55mph the tach will stay right around the 3-3500 range, and if I shift down to 3rd it does the same. Also, when this is happening it idles a bit rough sometimes dipping below 1000RPM’s then coming back up to 1-1500