Hi Gang,
I have an '88 RX with 140k miles. I was driving on a side road the other day when I saw a quick puff (small) of steam from under the hood. By the time I could get to the shoulder, the temp gauge was pegged.
I had the car towed home and thought I'd need to replace one of the radiator hoses. Imagine my surprise when I found that the plastic (!?!) part of the radiator had separated from the heat exchanger tubes. (the plastic appears to be attached by being pressed into some metal fingers - sheesh)
Anyway, I replaced the radiator, refilled coolant and started it up. It starts, but runs like some of the spark plug wires are disconnected. Very rough and NO power.
How do I tell if I blew the engine when it overheated? Up 'till now, it has run just fine.

TIA!

- kelly koop -

 

Pressure test the coolant system, if it leaks down several psi within 5-10 minutes you probably have a leaky O-ring (rebuild). If you haven't driven it much since the overheat, this next test may not work (not sure) but you can get your coolant tested for hydrocarbons (burnt fuel escaping past the O-ring into the coolant passage), if present, rebuild. Is the exhaust look like a steam train? Does the exhaust smell sweet? If any of the above are true you probably need a rebuild
Good luck.

Frank