A few things to look for when buying a used Mazda RX8. Body inspection is fairly straightforward; like any other car look for rust,  structural damage, accident history etc. Drivetrain; the engine is the biggest unknown when purchasing a used RX…. the first thing is how does the car start-up from dead cold and how does it restart when hot. In the case of cold start look for excessive blue smoke from the tailpipe; this is an indicator of worn oil control rings inside the engine and or how bad the oil seal “o” rings are. Either case suggest an old engine in need of rebuild or maybe an engine that was run with low oil pressure. Compression on a Rotary Engine can only be checked using a genuine Rotary Engine Compression Tester. Standard gauges can’t work because they measure only one pulse from each Rotor, the right tester will differentiate between the three pulses per rotor which is unique feature of Rotary Engines. In general, compression is not a tell-all because compression readings can read normal while an engine is consuming excessive oil or has overheating issues. Low compression is usually manifested when there are hard-starting problems when an engine is hot. Of course the  engine flooding-hard starting issues (when cold) that i blogged about previously are associated with tired engines with low compression.