i'm only getting lukewarm heat blowing out recently. any ideas to try before buying new parts like a thermostat?

 

If the engine is warming up good I would backflush the heater core. Probably clogging up on you. You can tell by grabbing both heater core hoses after running the engine at full temp for a while. If the inlet is significantly warmer than the outlet hose, there is insufficient flow.

 

Hello and welcome to FTE.

Are you sure that your thermostat is the problem? Engine gauge showing normal operation range?

Buckarcher beat me to the posts. I also agree with him.

 

im guessin youve made sure its full of coolant. --.my 93 f-150 had just slightly warm air.after we replaced the heater core its excellent,guess it was stopped up cuz it wasnt leaking.but if you need more heat NOW,you might try putting cardboard over part of the radiator,keep an eye on temp gauge so you dont overheat.if it does overheat,uncover some of the radiator.it works most of the time.

 

Along with verifying proper t-stat operation and checking for good coolant flow thru the core, check the operation of the heater lever/door combo to ensure that the door is fully closing, thus diverting all of the air thru the heater core. May also want to verify that the a/c comp is not comming on too.