Engine overheated - what now?
 

Went to lunch today and sat in the drive-thru line for +-5 mins. I had the a/c running but wasn't really paying attention to my engine temp because well i didn't think i had to. I smelled the unmistakable smell of coolant burning, looked at my pinged guage and immediately shut off my engine. Pushed my car into a parking spot and nervously ate my lunch. My tank boiled over and dropped maybe a quart of fluid out of the overflow. 15 mins later i turned on the key and the temp was at about 3/4 so i thought i would get it back on the highway for some airflow (and to get to a place where i could work on it). Temp was fine. Pulled into my garage and let it idle while i looked under the hood. The tank was slowing filling again and my guage was going up (no a/c running this time). I shut it down and it is still sitting. First 90 degree day i've drove this car. Motor started and ran fine but could some long term damage be possible? What should i do or check first? I'm a seasoned mechanic but know NOTHING besides all the bad stuff i have read about this car/motor. :banghead:

I seached the site first and found nothing....

Maintenance history ? Your location ? New or used ? Year model ? AT or MT ?

Normally, if proper maintain, it should NOT overheat. so there is a problem somewhere.

^^^ yup, that pretty much was what I was thinking.

any drastic mods to your car? Any chance something was impeding the airflow? (did you check for debris that could have gotten through the grill)

btw, there is nothing bad about this motor, it has a bad name because in REW days these ppl just up the boost without doing anything else, then the motor blows, they starts crying and swear that Rotary sucks. In fact it was just their own stupid fault.

mazda didn't just extend the warranty to 8yr/100k because there are no problems.

It is great they did this and are standing behind the engine now though.

Sorry for the lack of info.

04 GT MT 34k miles. All recalls were done by previous owner with good maintenance history.
Since i've bought it i've done my own. Radiator is not obstructed. Its not an airflow problem because when its moving the temp is fine. I'm gonna tear it down tonight. Good thing its not my DD. I hope my engine will forgive me this time..... Any more suggestions.

Is your cooling fan cycling like normal?

i had the same problem happen to me and im not even FI yet

This would be my first suspect too. Either that or low coolant level. Also check coolant concentration.

^+1

check ur fan, coolant concentration, and coolant level. oh also, might want to check for small leak on the rubber radiator hose. there are 3 pieces.

When was the last time you change the coolant ? Cuz your system might have bubbles in it, make sure you bleed it correctly.

Also pressure test your radiator cap. May not be holding pressure.

yes make sure fans are working! Anytime you are caught in a situation like this and have to use the a/c--ALWAYS __put the a/c control on fan setting 4. this automatically turns on a fan and it helps the car to not get into a non recoverable overheating situation. EVERY car is prone to this not just the rx8. Run a 70 % water and 30% coolant blend unless you live in the north and never ever use 5W20 oil!!
olddragger

Do you know if that will turn Fan 1 or 2 on ? or both ?

Check the fuses to the cooling fans, could be a simple blown fuse.

check your radiator , mine is leaking but not to the point where my car overheated.

https://www.rx8club.com/series-i-trouble-shooting-95/gentlemen-check-your-grommets-45395/

I had that same problem - check this thread.....


S

hmm, maybe I should check mine too. :o

My Renny overheated yesterday on the way to our BBQ. I was going through the Lincoln Tunnel and I noticed my water temp at 260+! I can't stop in the tunnel... so I had to get through and pulled on the first left, 3 RX8's in tow. Coolant EVERYWHERE... PA cops gave us some water and we booked it to Chris' house! :) I reckon I took a few thousand miles off my motor :(

It was a freaking radiator fan fuse that blew..

You win!

Replaced it and was able to hear the fan run. I'm an electrical engineer by trade and a rule of thumb is never to replace the fuse without fixing the problem first... well i violated that tonight. I'm gonna carry an extra in the car and see how long this new one lasts. I bought the car last November so this could have been blown for a long time. I rarely drive it anyway and this was the first time in high heat. I went ahead and flushed the coolant out and refilled under vacuum to prevent air pockets. I changed the oil to 5W-30 (i was using 5W-20) after reading a bunch of threads on here. I ran a compression check and the numbers were all consistently good. Lucky me. Its gonna be 90 tomorrow and i'll probably be looking to score some drive-thru food again so it will be a good test.

Thanks for all your replies... this site has so many knowledgeable people! At least there is a searchable thread now for this.

Ay! :)

I dont know because mine kinda heats up too. Today there was a time the temp reach 102 Celsius. It was never that hot. and my coolant is about 40/60 mix with water wetter. shouldnt heat up like that.

I should've check the fuse. Maybe tomorrow.

Does each fan has its own fuse? I forgot.

My car overheated about 3 weeks ago while driving in stop & go traffic. I finally made it home after sitting on the side of the road for about 1/2 hour. Since I had no idea what happened I decided to pull everything apart...what a PITA. The #1 fan overheated and melted the plastic around the post for the fan blade. I had to pull the blade off in order to see it. The #2 fan was fine.....I tested it by hooking it straight to the battery. I went to the dealer the next day to explain what happened and they simply told me Mazda is aware of the problem but they will not do anything about it....go figure. I ended up installing a 3.8L Ford Taurus fan that pushes 4000CFM and have not had an problems. I have the a/m temp sensor cutting the fan on at 190 degrees.......fan cuts off around 182 degrees.

Does the Taurus fan fit perfect ? or you just have to retro fit something ?

and how you hook the sensor ? pics anything ? :)

now that is a good idea--higher capacity fan and with better control. Yea is that taurus fan a bolt on ?
olddragger

thats a damn good idea....mine is at 170-180 normally and goes up to about 210 if im in traffic.....220 if its terrible traffic