Lexus Repair: 1993 Lexus ES300 Overheating, radiator caps, lexus es300

Question
Hi Zak;
We have had a 1993 Lexus ES300.  It has 140,000 miles.  We have owned it for 7 months and not sure how many previous owners.  I have had the timing belt, water pump replaced.  Last week the car started overheating and we had the thermostat replaced.  This did not fix the overheating problem.  The mechanic now says that the motor is cracked.  IF this is the case, why did he not know that before he replaced the thermostat.  Anyway, how do you know definitely that the motor is cracked?  I don't want to purchase a new motor if it could be something else.  And, if the motor is cracked, is there anyway it can be repaired without purchasing a new motor?  Thanks for any suggestions you can offer.

Answer
Hello Renee, Replacing the thermostat is a good thing to start with, radiator caps need to be checked also. I do not think the engine is cracked but could need head gaskets. Do you have a quality repair center such as a Lexus dealer or a Toyota dealer around. If so I would bring it in to one of them and have it looked at.