I just bought a 2005 Rx-8. The guy I bought it from stored it in his garage for the winter so it probably hadn't been driven in a while. Due to some recall, the engine was replaced in 2012 and he'd only put 4,000 miles on it since then (I verified this with the dealership). Anyway, as I was getting on the freeway, I decided to rev the engine to redline (I let the engine heat up before). When the rpm hit 7,000 the check engine light flashed once. Now, I can't remember if it stayed on before or after I pumped gas but it's still on now. Also the cooant light goes on and off intermittently but the coolant level is fine. The fact that the check engine light flashed like that makes me think it's a loss of compression issue.. but on a brand new engine?

 

A flashing CEL is a misfire, usually ignition related.
Get your codes read, auto parts stores do them for free.

 

+1 ignition or catalytic converter. FYI there was no recall on engines, just an extended warranty for 8 years / 100,000mi. Often when the engine is replaced, the root cause of the 1st engine's death are not replaced: ignition coils, catalytic converter. You'll probably want to get the history on those from the previous owner.

Wouldn't hurt to call Mazda for a run down of what all was done at the engine replacement, they should have records.

 

++ ^^

I suggest the things in the congrats thread below and coils (check plugs too). Also, I would check the CAT (pretty eash, 3 bolts, look in). I think the CAT check is going in the congrats thread next time I update it.

There are also some good recent posts on a $15 coil tester. I just bought one, but it is still in the box.

And, welcome.