What is the most likely cause of engine overheating in a 89 Honda Accord LXi?

Answer 1

1- incorrect amount of coolant 2- stuck thermostat If you turn the heater to HOT and run the engine does that reduce the engine temperature a lot? little? If a lot then look at #2. Other reasons for overheating include a worn out fan motor and/or clogged radiator. The original radiators on these cars had plastic tanks which would eventually crack and leak causing a loss of coolant. Check for a greenish colored residue around the top of the radiator. If the radiator is cracked, it must be replaced. If it is clogged, a GOOD radiator shop can clean it and replace the tanks (if they are plastic), or the radiator can be replaced. Cost of replacement is not a lot more than cleaning on these cars, and the confidence of having a NEW radiator is worth a lot.