So Im in a pickle, when I got my 2010 RX-8 at 47,000 miles back in October 2016 at a Toyota dealer (but all maintenance and compression check was done by their next door neighbor Mazda dealer)

The compression number they gave me was...

Rotor 1: 8.1, 8.2, 8.1
Rotor 2: 8.2, 8.3, 8.3

So it was in Excelent condition still...

Now the cars has about 65,000 miles.

However every once in a while very random my car takes 2-3 seconds to crank before the engine starts when the engine is just cooling down for 1-2 hours after a drive.

Its not really a hot start issue cause Ill be shutting my engine off for 5 mins, 15 mins, 30 mins and start it back up and fires up in about a second.

Its somewhere when the engine starts cooling down is the issue.

You guys have any ideas?

 

Well those numbers are from over a year ago so they mean nothing.

Got any video of the issue?

 

Is it possible your starter is slow? Is it possible your battery is not in the best shape? Have the ignition coils and spark plugs been replaced since you bought it (or rather, when were they last replaced?)

 

Ah...so I replaced the plugs around 50,000 miles...didnt replace the coils (I thought that was just a Series 1 issue). I put an Optima Yellow top battery about 6 months ago.

Wheres the best place to get type C Coils?

 

I suppose Mazda, but at dealer price, you may as well get BHR. You can always check AutoZone, either way you'll need to replace them at some interval, and AutoZone is cheaper. Coils are by no means a solved issue on series 2.

Get the battery tested, people from hot climates tend to find Optima's don't live very long in RX8 engine bays.

 

S2 starters are pretty decent. Not saying that they can't fail, though.

Our S2s come with Revision B coils, which are still prone to failure with age. Someone here had one fail at 20k miles. Another person had his S2 burn down from a cat fire on Reddit, which suggests coil failures as well.



There doesn't seem to be any long-term data on Revision C yet. The only RX-8s that have them from the factory are the RHD-only Spirit Rs, and most people just upgrade to BHR coils.

I don't know why people use the Optima Yellow Top. It's a deep cycle battery - great if you have an amp or something that can drain a lot of power, but the trade-off is that it's not as great at cranking as starting batteries. Optima also has pretty bad QA nowadays, so they are not worth getting from what I have read here.

Personally, I am using the MotoMaster Eliminator Ultra AGM from Canadian Tire. 5-year warranty, and starts very well. I also make the point of charging it once in a while with a battery charger just to make sure it stays healthy.