Coolant Loss & Overheat after 116k Miles on Original Engine & Too Many Autox to Count
 

So this past Sunday my beloved Renesis figured out the best way to depart was by dumping coolant after crossing the finish line on my 1st autox run.

I saw the coolant temp gauge swinging to the right, and coolant fluid just gushing underneath the engine bay, with liquid trail all the way from finishing line back to the grid. A bunch of helpful & friendly local rotorheads gathered around and didn't find obvious external leakage source. There was still coolant remaining in the system, when cap was loosened up and engine running after initial discovery. Pulling out oil dipstick show no sign of coolant/water mix. No smell of coolant from exhaust.

So I soldiered on and finished my 2nd & 3rd run. The temp gauge did swing to the right when stationary & idling.

Also had to drive about 21 miles back home at highway speed, while dodging traffic blockage. Plugged in the OBD2 and saw temp going up as high as 122C, and generally 109C, during the drive home with full heat blasting. Idled for a while after reaching home, and shut it down since then.

So here is my plan, and I'd appreciate any feedback/correction:

1. Top it with distilled water, and check for any external leakage for the whole system, not running.
2. Crank the motor with EGI fuse pulled or throttled floored and overflow cap off, see whether coolant shoots up. If yes, coolant seal is compromised, engine is done and rebuilt is on order. If no, proceed to next step.
3. Take out spark plugs from the bottom holes and examine for coolant/water pooling. If yes, engine is done and rebuilt is on order, and less re-useable parts for the rebuild. If no, do cooling system pressure test and fix the leakage source.

Still on original water pump & hoses & faulty overflow tank sensor. Only cooling system maintenance was periodic coolant flush.

At 122*c (251.6*F) your coolant seals have already been compromised. Most likely you also have warped parts. If your engine lasts much longer I would be surprised. Like you said check your plugs if no external leaks have been found. Chances are high no matter your engine will have to be replaced after these high temp heat cycles.

Diagnose properly, pressure test the cooling system.

probably a cracked port on the topside of the radiator feeding the reservoir.

pressure test the system and repair any leaks found, probably replace the t-stat and be sure the fans are working. but i have a feeling the engine is done, the excessive temps are likely due to air pockets forming in the cooling system due to combustion gases pushing into the cooling system.

Similar Situation
 

Hi Guys, i'm having an issue that could be related to this problem and i need help.

So, i've been having an issue when i just start the car, like the it hardly starts after some seconds the revs ran normal, i've read about the issue, and it could be some compression problems, if this is the issue, do i had to get another engine ?

I was having several codes, p0303, p0104, c0104, c0300 so i took my car to my mechanic tech guy, he worked several stuff, after that codes cleaned up, and i only have one code, the one related to the gas gap...

What I'm worried is, he showed my a video with a compression test he made, the video showed how with the coolant cap open when the starter triggers the water came out of the coolant bottle.

So he said, the engine has compression issues, and the air of the engine goes to the cooling system and that's is a huge issue, and i must buy another engine, is that right ?

Issue is because if i get revs to hide it reaches highg temperatures easily, any help would be appreciated..

In the case i have to buy a new engine, what about a rebuild one, like the ones in sale in ebay ?

I wouldnt trust most people on ebay. Thats my advise

As for rebuild, it really depends on ur budget and ur engine's current condition. I took apart a couple dozen renesis apart, 90% of the time all apex and rotor housings are shot. Irons are 50/50

ok so, i'm buying a new engine, actually is on transit right now, sometimes i feel like this forum is getting isolated or something because almost nobody answers anything, is it a reflex this car is dying already, i love my car but i'm feeling like selling it...

The lack of responses is largely because there is nothing else to add. You clearly knew the cause of the engine failure, and NYCGPS answered your question accurately. Not much else to say about it.