Owner of 05 RX8, this weekend enjoying a long drive around Bristol area and suddenly overheated with steam coming from engine Pulled over, let cool, refilled with water, drove home. Now when it gets to temperature, lots of water leaks out from top of the radiator which is under air filter box and coolant plastic tank so cant see exactly where. Concerned from what I am seeing that could be a crack in top of radiator radiator BUT why only once hot? Maybe as this is when pump kicks in? how easily can I get to the top of the radiator to check as could be a popped or cracked hose. Do have some mechanical knowledge such as oil changes etc BUT if a big job, will roll it into my local garage.



Took video but cannot attach due to type...if wanted can forward.on.

 

The thermostat only sends water to the radiator when the engine is nearly up to temperature.

 

The radiator is a pain to get to. It’s not difficult, just time consuming. I’m sure you can find instructions from the forums somewhere on a radiator diy replacement and use those to diagnose it.

Best of luck

 

Cheers all, think might be time to put into the garage. Wonder, if remove air filter box, would this least let me see the top of the radiator. Might just be a loose hose can fix?

 

From my experience, if it's still the stock radiator you likely will need to replace it. Usually the leak happens because the plastic nozzle rots out and breaks. Sucks that you need to replace the whole radiator for that but it will be a good time to upgrade to an all aluminum 2 row racing radiator. It's cheaper than stock and performs far better.

 

When you say plastic nozzle, is this integral to the radiator or the hose that connects to the top? I have a sinking feeling this is going to lead to a new radiator.

 

There is no real way to fix it easily. It's easier and cheaper to just buy the replacement radiator. The aftermarket ones work perfect and last pretty much forever. The stock radiator is pure garbage.