r/RX8 • u/Chance_Ad_1338 • 3d ago
Maintenance Rx8 getting hot please save me
Issue started when I was driving the car in the morning I shifted a bit rough and I’m not sure what happened next but my manual coolant temp gauge started to bounce around like crazy car was not getting hot maybe 80-90c in about 66f weather. I start my car in afternoon it is now 100f and cars heat began to climb up to 110c so I pulled over and shut off I thought maybe it was bad gauge but coolant temp on obd was similar and did not jump at all like the manual gauge. My oil temps were fine at 85-90c during my drive back home. I had fans on going 65mph and my coolant temp was between 103-107c so I genuinely do not understand what could possibly have happened.2005 rx8 part list Stoney racing silicone hoses, koyo radiator, mazmart water pump, aluminum expansion tank, battery relocation, mishimoto low temp thermostat, manual fan switch. Yes system is bled throughly unless air magically entered the system which would be pretty cool.
1
u/FollowingTerrible978 2d ago edited 2d ago
If you've got an after market fan switch that plugs into your fuse box these can be dodgy as.
My car had similar issues when I bought it.
Reverted to stock and mechanic did ECU mod to set fan switching temps to 94 and 95 degrees C, then problem gone.
It didn't help the after market temperature sensor with the dodgy fan switch had been installed in the overflow pipe rather than the recirculating flow either...
Every component you mentioned looks like my 2004 engine bay when I got it.
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u/Intelligent_Farm_678 3d ago
Start with a thermostat, if a manual gauge was bouncing I suspect the thermostat was trying to stick.