My '98 F150 with A/C ..........

Air temperatures have been 10 to 40 degrees in the mornings for the past few months.

When I start it and let it run for 5 minutes to warm up, the temp gage has barely moved, and heater air is not noticeable warm.

Have to drive it for 5 miles before cabin heat is coming through. Takes 10-15 miles to get the cabin mildly warm. The temp gage runs steady at a 1/3 from C to H.

It's always been this way.

is this typical for this engine/heater, or do I jump right into the thermostat?

 

Sounds like you need a new thermostat.

 

Sounds normal to me.

I don't like it either. But nobody has ever found anything wrong.

 

I timed how long it took my 2001 4.2L v6 to warm up. I started it while it was completely cold, and turned the heater on. I drove completley normal at speeds of 35-45 mph, and it took it exactly 3-1/2 minutes to blow hot air out the vents.

 

FWIW, I noticed that I got hot air out of the heater much faster when I switched to an electric fan.

 

i made a post about this a couple months ago. i haven't toar my thermostat out to get a look at it yet.

i have checked mine the lazy way, simply starting the truck up cold, let it idle for a min or so. then grab the heater hose see if its warm, then grab the upper radiator hose (close to the block) and see if its warm. if you have any heat comming from the radiator hose the thermostat is probally stuck open.

i have checked mine like this. my radiator hose stays COLD and the heater hose is burning hot . my thermostat seems to work fine.

i don't get it the heater core seems to have plenty of heat running threw it????

 

Howdy,

Your thermostat is stuck open. U need to replace it.

Stengun

 

Sounds normal to me. It takes me 14 mins flat to drive to work (rush hour) and I'm about 1/2 way there before there's heat blowing out the vents. (Full blast, max heat) I noticed you get full heat faster if you sit there take it and do not turn anything on for the 1st 5 mins so the engine warms up faster. Fortunately, I'm from the midwest and it never gets cold in TX so I drive with the windows down pretty much all the time. Cabin dust is more an issue than cold.

Once every 10 years LOL.

 

I checked mine the same way as THEFORDGUY. Mine works the same way also. I feel everything is working normally.

I also timed the warmup today. Temp is a balmy 35 this morning. I idled about 1 minute, then started normal driving about 40 mph. Total time to operating temp was 11 minutes.

 

I just bought mine, but it is warm enough to begin blowing hot air withing 2 miles and 3 minutes (depending on the route I take). I was shocked at how fast it warmed up.

I think I read that there was a problem with the vent door sticking open and not allowing the heater to seem as warm as it should. Check the recalls and service bulletins.