hey guys. i have an 04 rx8 with 39xxx miles on it. my electrical fan stays on EVERY time I turn off the engine no matter the ambient temp outside. it would stay on for about 5 or 10 min and shuts off. again, EVERY time i shut off the engine... anyways it started to get worse. the other day i noticed my temperature gauge would fluctuate. it doesn't go up much. only about 1 or 2 nicks. normally it would stay in the middle of the gauge, but now it goes up a couple notches and goes back down to the middle of the gauge. its nothing drastic but i still don't think its normal. any suggestions? is it thermostat or water pump or other? thanks

 

The fan staying on means that your coolant temp is over the trigger threshhold when you shut off the car, so that's working at intended. Your temp gauge moving AT ALL from where it normally sits is bad though, as it won't start moving until you have cross the critical temp stage.


As for why you are overheating, it could be anything from radiator cap failure, a coolant leak, air in the system, radiator blockage, thermostat failure, etc...

 

is there any way to narrow down what the culprit is? do you recommend doing anything before taking it to a mechanic? thanks

 

Recommendation,

Follow the cooling stuff behind the First $100 Thread in my signature. The rest of it does not hurt as well. And, make sure there is coolant. If the gauge moves, even a little, it is hot. The list is what I did to keep mine cool in Florida, as well as fix some other things. If still doing it after that, might be something else.

 

The factory coolant temp guage doesn't even move until 230F-240F. Those temps alone can be an engine killer so do not play around, get this addressed ASAP. Your car only has 39,000 miles on it but is 8 years old. If i were you I would flush the coolant, replace the water pump with the updated factory one, replace the thermostat, and replace the radiator cap. Then when that is all done do a cooling system pressure test. Make sure you properly bleed air from the system.

M A Z D A

Engine ----> Cooling system --------> Engine Coolant Replacement.

 

damn.. more money. i just dropped 500 bucks for springs/shocks, and now this happens. thanks for the tips guys.

^9k since im at it, i was thinking about the REmedy t-stat from mazmart. water pump is too expensive so im gonna go oem with that. but what is this updated factory one you're referring to? should i order through the dealership and get ripped off or is there one online? partsgeek.com has like 4 brands. is it the Gates pump with gasket?

Mazda RX8 Water Pump - Water Pumps - Gates GMB A1 Cardone Beck Arnley - 2004 2005 04 05 - PartsGeek.com

thanks and sorry for asking all these questions.

 

It's far cheaper than paying for a rebuild Honestly I have the Mazmart water pump and thermostat and I saw no difference really so if you are short on money, don't bother. The water pumps for the S1 had a change on the impeller, all remans are shipped with this new part #. I'm not sure if the aftermarket pumps have a different impeller design or not.

 

haha i don't even want to think about the rebuild fee.

thanks for the heads up on the mazmart pump and thermostat. i guess i'm off to the dealer parts department then and go oem.

 

That's just my opinion, many love that water pump and thermostat like it was their own child Same goes for the AFE SS, I just don't get the hype.

But if you want to save money just go through RockAuto Auto Parts

 

just an update. it was the thermostat that went bad. just put in a new oem one and it works great now.

thanks for the help guys

 

Hello, I replaced my thermostat, radiator, temp sensor, and new coolant..... however I am still climbing temp when idling with the ac on, or climbing steep inclines. Any ideas on what else it could be? Thanks in advance!

 

Are the radiator fans coming on? Are there bubbles in the coolant bottle (don't open it hot, obviously, open it cold and then start the car)?

 

Hello Loki,
The fans are functioning properly. I used the cold start "burping method" and was able to get some bubbles (est. 20 little bubbles) to come out after about 25minutes, the bubbling stopped. The fans would kick on cooling it back down before anymore could come out.
*** Should I keep repeating the method after every cool down? Any faster options possible?
Thank you!

 

You shouldn't need to do this more than once. It's good that you burped the system, and it's good that you're not getting more bubbles, but it's a one time thing.

It overheats at idle? In traffic? What about at speed?

Do you have the plastic tray that goes under the engine and rad?