Nissan Repair: Engine Overheat, blown head gasket, radiator leak

Question
I drive a Nissan with a GA15DE engine manufactured in 1996. It has done only over 70000kms as i've been using it as a second car.
The car was running fine until yesterday when it overheated. I made a big mistake of not paying attention to the engine temp gauge and was confused when all of a sudden the engine started making a strange noise (similar to a vibrating noise made by small engines). Still unaware of whats going on i continued to drive as i was very close to home. After driving about 700 meters further, when i stopped the car to turn to my drive way, it stopped & couldn't get it started back. It was then i noticed the overheat gauge showing the maximum value possible.
Dead Scared I impatiently waited the engine to cool for some time and tried and it started just as it used to do before. Then i quickly added water to the radiator while the engine was running until the optimal water level. Engine kept running normally without any misses or anything but i did find a leak in the radiator which caused the coolant to leak out rather fast which was the root for my problem.

Anyway, i can get my radiator fixed in no time but I'm really worried whether this caused any major damages to my engine. Can you please tell me how to identify any such damages?

Thanks a million.

Answer
Hi Amal -

First of all, check the thermostat for proper operation. Sometimes that causes overheating problems in the first place. It also could have caused your radiator leak. I would not want you to go through that again!

Secondly, the most common result of an overheated engine, especially after continued driving is a blown head gasket. If your car is running smoothly, and no steam coming out of your exhaust pipe (you can determine steam by watching the smoke coming out of the pipe - if it is white and dissipates quickly, then that is steam), then you should be OK. To be sure, you might want to do a compression check. I think the norm is about 120PSI per cylinder, and there should be no more than 10% variance between cylinders.

Hope this helps
calvin