So I'm currently in a tow truck with my s2000 in the back, and I've got a trackday tomorrow. I'm having a hard time finding someone to see me, so I am going to have to try to diagnose this myself.

I was driving on the highway, temps were fine for most of the trip, but then temps began to rise... 5 bars, 6 bars.... but not to overheat or anything, but then POP and spewwww went coolant everywhere. I pulled over, and I had empty coolant, none left. I get some water, and pour it in the radiator, and it does NOT leak from the radiator, instead, it's leaking from the upper part of the motor.

Car running fine otherwise, it's almost like a hose popped off, but I really couldn't see. It's coming out fast, like... a faucet at half turn speed at idle, if you hit the gas, it just gushes right out.

Now, I did just replace the radiator with a mishimoto, but I didn't change anything or touch any clamps on the engine's side, just literally detached the old rad and replaced with the new. Again, not leaking from the new rad, it's coming from the engine, and ive made no change in that area, but it sure seems coincidental.

Any help? what should I look for? Looks like it's coming from the upper part of the engine, and by "looks" that's where it's gushing out from.

Thanks so much!


Edit:
Just going to put the end here so future searchers can see.

Upper radiator hose split/cracked and was spewing everywhere. It really looked like someone took a knife to it, very odd. No one did of course, but that's just what it looked like. From the point of bursting, it took me about 4 minutes or so to exit the freeway and get to a gas station, where I proceeded to idle it for a while after adding water. At idle, it wasn't leaking, it was only leaking under pressure (when throttle engaged...so I had to be in the car), so this took me a while to diagnose unfortunately. That said, after replacing the upper and lower hose (might as well do both if one fails), we ran a block test and all appears well. I also just drove it 4 hours home no issues.

Replace your hoses every 5 years. I have no idea how old mine were, but I've owned the car for about 5 yrs...so older than that. My guess is when I went to install the radiator, and had to wiggle the tubes to get them off the radiator, that was enough to start a crack on the old hose.

 

If you didn't touch the engine how did you bleed the air out? may be you had a massive air lock and it found the path out of least resistance.

 

Possibly coming from the top front bleed screw.

 

Split the upper rad hose near the connection point under the intake manifold? Get the car home, re fill it, start the car and wait for it to start to spew again so you can pinpoint the issue.

 

have you figured it out?

 

6 bars is over 273*F. I would be more worried about your motor and head gasket than I would be worried about a track day

 

x2, investigate the issue. The image below is from the Modifry website. Hope it helps.

 

Yeah you aren't going to that track day. Did you fully bleed the coolant after the rad install? Tell us specifically what you did. If you just put the new radiator in and refilled it you didn't bleed it. Some pics will help as well.

 

Upper rad hose was the culprit (it split), did burp the system after rad install, had no bubbles, and car was fine for ~2 weeks with no heat issues and was good for the first 1.5-2 hrs of the trip down.

Will add more information of what happens if I remember to later. Did end up going to the track weekend...juuuust not in the S. ...been a long weekend!

 

how many miles/years on the radiator hoses that split?