Low engine temperature 03

[RPosey]

I have changed the thermostat 2 times, still no heat in the cab. The engine will reach operating temp with fast idling at 2000 rpm for 5 minutes or so. It will heat if cardboard in in front of radiator.

 

[steved]

I have changed the thermostat 2 times, still no heat in the cab. The engine will reach operating temp with fast idling at 2000 rpm for 5 minutes or so. It will heat if cardboard in in front of radiator.

If the engine is reaching operating temperature, and you still have no cab heat; I would suspect a faulty component in the dash that controls the airflow or the coolant flow to the heater core.



Just another possibility...

 

[rscurtis]

Steved is correct, you should have heat long before the engine reaches full temp. My signature truck takes about 14 miles for the thermostat to open in this weather (starting from a 50 deg. garage), but has some semblance of heat after 4-5 miles, even though the guage hasn't moved yet.

 

[jelag]

1 - after the engine is warm, grab both heater hoses and see if they are the same temperature... . if not... you've got a flow problem. . or an air bubble in the heater core. .

2 - if both hoses are hot... that means the water is circulating in the system... than you've got to assume that the controls aren't doing their job...

 

[Missouri Mule]

Blend/temp doors on 3rd generations are known to break.

 

[RPosey]

OK, I am back. The fan works as designed. I am convinced it is a air pocket in the block/heater core. The truck came in with the heater bypassed because of a leak. We replaced the core as well as the plastic heater doors. The shop belongs to a friend of mine. Thanks for the comments.