Used Cars: Quick Question, head gaskets, model truck

Question
Hello,
    I am in the process of buying a used truck. It seems as though every older model truck I run into the motor has been "completely rebuilt",must be my lucky day...To come across so many trucks who's motor has been rebuilt : ). How can I tell if the motor has been rebuilt other than a compression test...any suggestions would help. Regards-Skyler
PS..I'm not even sure a compression test works either.

Answer
Well when considering buying an older truck, make your decision, without consideration if whether the engine has been rebuilt or not.  There are several things you can check on older engines to know what you are getting, it would be best if you had a mechanical minded friend that could help you out, if you are unable to check things. Listen closely to the engine on a "COLD" start up, you want to hear how it sounds when it has been sitting a while, and the oil has all drained to the bottom of the engine. You can check "Blow by" by taking the oil fill lid off while the engine is running, if there is a lot of "smoke" looking stuff coming out, than the rings are getting bad, and the engine probably has not been rebuilt, or rebuilt properly.  I would run the engine to see how hot it runs, and then you can feel the exhaust.  If it feels pretty moist it could have head gaskets leaking, and you can also check the radiator while it is running, if it is bubbling back up through the radiator than you could have head gaskets as well.  You can pull a plug to see if it is excessively black, like running rich, but if you do not know what you are looking for, it will be hard to determine that.  Check all the gears well, and if it has overdrive, run it up to about 60 mph and kick overdrive off and on, intermittenly to see how it handles that.  These are little tricks of the trade but fact of the matter is that if you dont really know what you are looking for, it will be hard to determine some of these.  A mechanical friend would be extremely handy.  You have to do these test under the right circumstances to insure your safety, for instance, you dont want to pull the radiator cap to check for bubbling back through after the engine is hot and been running, you need to do that before it gets hot.  Like I said a mechanic to do this for you, if you are not mechanically inclined, would be well advised.