2000 GMC Jimmy SLT

[JamesTH]

Hi,
I just noticed that when I run the heat after running this vehicle for quite some time no heat comes out of the vents. Any ideas on what could cause this and if so how can I fix it? I did check the two lines running out of the firewall and they both are hot to the touch. Any help would be greatly appreciated....

[maxwedge]

Welcome to AF, will it get hot if the engine is speeded up? Any sign of sludge in the coolant or radiator?

[b1lk1]

Time for a system flush, but be warned. I had similar issues and after flushing my system it took out the intake manifold gaskets, heater core and the rad. All very common issues on these trucks.

[maxwedge]

A little quick on the system flush without more info, temp doors, and actuators may still be in the mix.

[gatorbite2]

i have a 2000 slt also and my problem was the heater core was clogged up

i had them back flush the heater core and then flushed the system

and to be honest i couldnt believe how much heat i have now

i had that done winter of 2008 and no problems with intake or anything else

just a idea good luck

Jeff

[b1lk1]

I don't mean to imply that a flush will definitely cause issues, I just know that it can and one should be prepared for it, especially with these trucks, lol.