anyone have any ideas? truck warms up nicely gives heat for about 10 seconds then runs cold with the blower on. do the heater cores have blockage problems?

its 14 degrees and no heat.

Thanks Garbz

 

First off check the engine coolant quantity . Does the engine temp come up somewhere in the Normal range ? When was the last time the cooling system was serviced ? Any interior coolant leaks ? Its possible the heater core is clogged , but you need to also check to make sure the engine is warming the coolant to a temp where the interior will be warmed .

 

14 degrees and no heat??????????? Why dont you bring it to a repair facility and have the problem fixed. If you find out what the problem is are you really going to be able to fix it, when its 20 degrees below freezing?!

 

Guys i dont drive this truck the wife does. she has a bad habit of telling me of problems months after they occur. when they become critical. It comes up to tempature. The coolant is full
with new mix. i replaced the heads this summer when it started to use coolant. im leaning towards a blocked heater core. the hose to the core is very warm where the hose from the core is cold. i checked the routing of each hose and they are correct.
Thanks
garbz

 

Yes , If you have one warm hose & one cold then chances are the heater core is clogged . The good news is yours is pretty easy to replace .