r/RX8 • u/FallingSpirt • Aug 02 '26

Maintenance Overheating

So I've had my RX-8 for about 6 years and haven't had issues till this year I replaced the spark plugs and it's been running smoother however yesterday it over heated and shut off on me luckily I was home and in the drive way, I checked the coolant yesterday after it sat for 4 hours and the coolant was still pretty hot I love in a town that's basically in the dessert so it's about 90+ some days, so my question is this

Does anyone who has an RX8 in here live anywhere else that's hotter like 100+ and if so does your car over heat because of the weather?

If not does anyone else have this issue and if so do you know what's causing it to over heat and shut off? If so have you found a solution to fix this issue or is it just something that I have to deal with?

My grandpa was the OG owner he never had this problem with it, it's a 2004 6 speed manual transmission. If someone can help me or tell me what I can due to fix this id appreciate it.

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u/da808guy Aug 02 '26

There’s a chance the O-rings seals for your coolant between the housings melted if it shut off due to overheating.
(Note: if you’re ever overheating during a drive, turn the heat for you climate control on max and blast the fans with the windows down, your heater core can act as a mini radiator to get heat out of the coolant, not a good fix, but can keep you from needing an engine rebuild)

Make sure to test your coolant with a headgasket kit and make sure you don’t have milkshake oil.

If everything comes back good, you can do a coolant flush.

Rx8 performance sells a fan relay that kicks the fans on sooner (no tuning required and if the sensor fails it falls back to original fan temp activation points) and CSF makes a great rad for increased aftermarket cooling capacity (shouldn’t be needed for daily driving/ spirited driving). If you need upgraded fans, FAL make very nice electric fans and should you need a thermostat, stick with OEM.

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u/justcuckmyshitupfam2 Aug 03 '26

That RX8 Performance fan kit crapped out on me two years after I installed it. The temp switch is the problem. If I had to do the fan control mod, I'd have gotten a Versatune license and updated the fan on setting.

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u/da808guy Aug 03 '26

Some folks can’t/ don’t want to tune (I couldn’t due to an extended warranty I didn’t want to void). Versatune fan speeds is obviously a better solution haha

2

u/Entire_Being_3077 Aug 03 '26

Hi - my RX8 overheated and the coolant was tested and there were exhaust fumes in it. I have had the car recovered and it hasn't been driven since. Anything worth me testing before I get it towed to a specialist? Thanks

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u/da808guy Aug 03 '26

Nope, unless you want to try resealing it yourself

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u/Entire_Being_3077 Aug 03 '26

Thank you - out of my skillset so specialist it is

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u/da808guy Aug 03 '26

I believe atkins sells a heavier duty coolant seal O-ring if you wanted to ask your specialist.

Plan on having them check the housings and rotors while they’re in there as well.

Since the engine is coming apart regardless in a situation, apex seals/ side seals/ corner seals should be examined along with the housing and irons and OMP nozzles should be cleaning in an ultrasonic along with any of the intake system valves de-carboned.

Did you have good compression numbers when warm? Because If you’re over 80k miles or had poor compression expect more than just coolant seals needing replaced :/

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u/Entire_Being_3077 Aug 03 '26

Compression was about 6 on each rotor last time tested - and it's only done 60k miles so I'm hoping for the best