1996 tahoe weak heat/ flow

[Schurkey]

Good chance that fewer flushes would have been needed if you'd pulled the block drain plugs to let the rust and scale "out".

Lotsa rust settles to the bottom of the engine water jacket, gets kinda stirred-up during a flush.

When you're done flushing, letting the flush water out of the block drains eliminates the problem of flush water diluting the anti-freeze.

 

[Natedawwg]

My heater core gets roasting hot and the lines om the fire wall are correctly hooked up everything is brand new radiator hoses heater core stat i cant explain the now flow in the radiator nothing showes signs of clog other than weak heat/ flow i belive the blower and the evap core are the issue but i will alsp try flushing a few times

 

[Natedawwg]

My coolant is extreemly clean aswell i would expext to see nasty coolant in the resivoir.

 

[Natedawwg]

The heat temp from vents is barley enough to stay warm but core lines are roasting cant hold more than a sec on fire wall

 

[bretcopsey]

This was my attempt at suggesting “maybe” if you aren’t seeing coolant flowing clearly through the tubes in the radiator, then perhaps the same is happening with the heater core- not completely blocked, but not enough coolant volume flowing through to have a sufficient effect on the air being drawn across the heater core by the blower fan.

This was my theory with mine. The restrictions to the radiator weren’t enough to adversely effect engine temp, but if the heater core was also severely restricted it would have a greater impact due to its much smaller size. I may be completely off on this, or maybe just got lucky?

Also clean coolant could be result of a previos “drain and refill” rather than a true system flush-my coolant didn’t look too bad before I started.

Hoping for speedy resolution for you regardless what the issue is!

 

[GoToGuy]

The heater core, being a small tube detached reservoir with small ID hose has less flow, volume flowing through it. So it acts like a " settling pond ". When doing a radiator, coolant flush and fill, pull off the hoses, inlet and outlet on the heater core at firewall. Take your garden hose and at high flow direct the water in the inlet and then the outlet. If your lucky you might get to see all the " mud and gunk " blow out of one or both of the tubes.
Engine operating temp being normal but low heat out of ventilation ducts, is one of the indicators of clogged heater core ( heat exchanger) and or blend door malfunctioning. That is for those us with constant flow heat exchangers.
Then there are Tahoe, Yukon , Suburban crowd that have extra, auxiliary, rear heating , selectable on / off ( coolant flow/ no flow) repair fun times two.
So just a good technique when coolant flush and fill, direct manually flush the heater core. As Mr. Shurkey reminds" block drain plugs!" The junk settles at the bottom of the coolant passages, those areas not having coolant flow are asking to be overtemp, inadequate cooling.
Good luck!