Odd heater question

[BlueBayou]

Hi all,

Here is an odd story, well odd to me and maybe normal to the trucks. I have never really noticed this before but the other day I did. Scenario.... Its chilly out side, I wait for the truck to come up to temp, kick the heater on and it blows ambient temp air. I step on the go fast pedal and suddenly hot air!

Now I notice that while at a traffic light idling it starts to blow cooler air through but once I start to move it warms up very quick. Is this normal? I guess I never noticed before because I used to not drive much in the city and mostly on the freeway. This is the first winter I am using the truck as a daily and I am wondering if this is normal. It is like there isn't enough vacuum at idle to hold the blend door open in the heater or something.

In the end its not a huge deal, just more curious if anyone else has noticed this same issue before.

[ve7fet]

Well, there is no vacuum on your 6.0. There's an electric vacuum pump mounted on the passenger's fender that controls all the HVAC stuff.

Could be a thermostat issue. More go, more heat!

I know my changes a bit depending on engine load, and that correlates to the ECT I am watching on the gauge.


Lee

[BlueBayou]

Originally Posted by ve7fet

Well, there is no vacuum on your 6.0. There's an electric vacuum pump mounted on the passenger's fender that controls all the HVAC stuff.

Could be a thermostat issue. More go, more heat!

I know my changes a bit depending on engine load, and that correlates to the ECT I am watching on the gauge.


Lee

LOL, yeah you got me... No vacuum produced by the motor. I know the Tstat is good as I swapped it for a new one when I did water pump, coolant flush and EGR delete. I will keep an eye on ECT and see if there is a correlation there though. Thanks for the idea

[AMBUSH OUTFITTERS BC]

What did you find. mine is doing the same but it -30 c here so i am searching for info mine an 03

[BlueBayou]

I haven't found a thing yet..... It still does it no matter what temp the truck is at. I come to a light or sit at idle for a few seconds and it cools off. Not cold, just cooler. Once I pull away its nice and toasty again. My ALT is charging great and I just bought 2 fresh Motorcraft batteries last weekend so I know its not that. One person asked if it had to do with my EGR delete but I honestly don't think it would.

[AMBUSH OUTFITTERS BC]

well after checking out all the info i found i this site. i pulled my bully dog chip and that brought my temp gage down.(deep down i new i had head gasket issues )but still had cold air with no load on eng, checked heater hoses cold on one side hot on the other, rev it up cold side warms up pluged heater core,

[BlueBayou]

I will have to look into my heater core and see if there is an issue..... right now the truck is down with a no start condition and I suspect FICM