Report Fixing Hard Overheating Problems in 92 - 06 Lexus ES250/300/330 Posted June 8, 2010 I have a 1993 lexus es300. Ihave had it since 2008 and have had lots of small problems .My first problem was solved with help frome this forum change the efi relay solved my hard to start hot problem which is why I must inform my friends here. My car had been running good freash tune up with the works. Well i had to drive frome baltimore md to lancaster va, about half way there i started running hot by the time i arrived there i was in the red.On the way back my top radiator hose bust i was past red i would pull over to let it cool off an hour and 15 minnets of driving in the red that fast i parked in a mr tire shop and was told nothing could be done my head gasket was blown towed the car the rest of the way home $250 worth .Finnaly at home to other shops same results blown head gasket. I was on the phone trying to buy a new engine when the guy up the street who have worked on cars all his life cheked out the car He told me nothing was wrong with my engine he said that lexus uses the strongest head gaskets in cars today he took a hammer and started banging under the car the temp guage fell back to normal half way i couldnt beleave it he said my catalytic converter was clogged tight and red hot the exhaust had no were out but through the engine causing it to heat up way befor the ecu could cool it down and by tapping on the converter loosend it up just enough to stop the overheating I put lexe in the shop he sent me to and it was confermed so befor spending big buks on new engine check your catalytic converter.