Tom

Tom,

Q I have a 1988 Chevy C/K1500 pickup, 5.7-liter automatic. Recently the

truck has been overheating. The air temperature was about -5° F this morning
when I went to work (four miles away). Two miles into the trip, the truck
overheated and the temperature gauge pegged close to “hot.” I recently had
the water pump and thermostat replaced; I am not losing any antifreeze.
What problems could possibly cause the vehicle to overheat?

Thanks, Peter—Appleton, Maine

Peter,

A Have the cooling system pressure tested to make sure there are no leaks

in the system. If none are found, then have a cylinder leak tested to determine
if the engine has a blown head gasket or a cracked or warped cylinder head.
For further verification, have a block check performed to see if there are
hydrocarbons in the cooling system when the engine is running. During a
block check test, the technician will take a sample of engine coolant and mix
it with a special chemical that identifies if there are unburned gases in the
coolant. Good luck!