heater temp feels cooler than before

[modmonster2008]

so recently i have been noticing my heater isnt as hot as it is when the temp indicator shows 85, i ran several flushes in the cooling system and made sure there were no clogs whatsoever, no leaks of water anywhere, radiator is clean, thermostat is new, radiator hoses new, heater valve bypassed, but it feels like slightly hotter than warm air, is there anything else i can check? thanks

 

[Poodles]

Did you change the t-stat before or after the flush?

 

[modmonster2008]

after the flush, the old one seemed clean still but i changed it out, normally the car would have heat when the gauge is at or below the 1/4 mark on the temp gauge but now even with the gauge up there the temperature of the heater feels like the climate control shows 75 not 85..

 

[mkiiichip]

Are both heater hoses, as hot as the rad hoses?

 

[modmonster2008]

after driving about 15 minutes they are almost the same just between 2-5 degrees farenheit difference between the two heater hoses, is that a bad thing? its just odd to me that 2 weeks prior to my head gasket replacement the heat started heating up with the gauge even at the 2nd mark, now it takes longer to heat up

 

[modmonster2008]

would there be a possibility that it is an electrical problem? i have replaced my thermostat, flushed the cooling system, the system and the reservoir is topped off and the tank is between the low and hot levels. I have bypassed the heater control valve as the vsv on the control valve read a high resistance value so i just bypased it. I dont hear the waterfall noise anymore after replacing the head gasket but i still have the same problem i have been having since owning this car. At times the heat isnt as hot as it should be when it says 85 on the climate control, and when the cc is 84 or below the air blows either slightly warm or just cold air like the temp is at 65, is there any electrical wiring/switches/relays or any sort of sensors i should be aware of that can be causing this issue? pls let me know, thanks!

 

[modmonster2008]

updates, i took my laser temp reader to both heater hoses, the hose by the water valve reads around 160 degrees and the one by the intake manifold reads around 115 so im guessing i have a clogged heater core, currently i have put some cooling system flush in there to see if it can free out the heater core without having to remove and replace, is there any other things i can check out as well?

 

[bombinuass]

mines the same way... anthing under 80 is cold anything over reads warm and sometimes it aint warm

 

[mkiiichip]

You can flush it the opposite way with a garden hose, it works sometimes.
My old boss has this rig to hook up a water hose and compressed air. You would fill the heater core with water, then blast it out with compressed air, that thing would shoot water like 30 feet out of a heater hose. It always worked. But i could see it ruining a weak core.

 

[modmonster2008]

tried that today and it worked, backflushing took out large residues of crap sealant i put in there months/years ago that collected in the core, thank goodness i have extreme hot heater now that the rainy days and low temperatures are here, only thing i did was i had a gauge at the gun reading at 12psi as the system was designed for around that pressure so i didnt want to have more pressure to ruin the heater core, although at times the heat would go cold when the cc shows 84 or lower, are there any sensors that may need replacement?

 

[bombinuass]

tried that today and it worked, backflushing took out large residues of crap sealant i put in there months/years ago that collected in the core, thank goodness i have extreme hot heater now that the rainy days and low temperatures are here, only thing i did was i had a gauge at the gun reading at 12psi as the system was designed for around that pressure so i didnt want to have more pressure to ruin the heater core, although at times the heat would go cold when the cc shows 84 or lower, are there any sensors that may need replacement?

now what did you do? seems like i need to do this

---------- Post added at 10:42 PM ---------- Previous post was at 10:41 PM ----------

where do i flush it from

 

[mkiiichip]

The heater lines at the firewall, you need to flush the thing inside the cabin.

 

[modmonster2008]

yeah the inlet hose of the heater core is the one on the exhaust side the outlet is the intake manifold side, i backflushed the heater core so i ran water and pressure from the outlet to the inlet (reversed flow) until i got all the crap that was in there and the water was coming out clean..

 

[bombinuass]

thank you. ill try this tomorrow.

 

[modmonster2008]

if you use compressed air use pressure below 15 when the gun us pressed because you wouldnt wanna rupture the small lines in the core, and i flushed the heater core with water from my hose gun with the knob on the wall turned halfway you wouldnt wanna have excessive pressure going into the core as well, just enough to back flush it

edit: you might wanna have two heater hoses about 1-2 feet long, one going from the inlet (pass side) down to a catch pan and one from the outlet (driver) for the garden hose to push water into, thats how i did it, the catch pan is just there to see how dirty the water is and all the crap coming out of it, after that i still ran a engine coolant flush in the system and ill be removing that in a week or so..

 

[bombinuass]

okay thankyou.

 

[ProfessorHaddock]

if you use compressed air use pressure below 15 when the gun us pressed because you wouldnt wanna rupture the small lines in the core, and i flushed the heater core with water from my hose gun with the knob on the wall turned halfway you wouldnt wanna have excessive pressure going into the core as well, just enough to back flush it

edit: you might wanna have two heater hoses about 1-2 feet long, one going from the inlet (pass side) down to a catch pan and one from the outlet (driver) for the garden hose to push water into, thats how i did it, the catch pan is just there to see how dirty the water is and all the crap coming out of it, after that i still ran a engine coolant flush in the system and ill be removing that in a week or so..

Hey modmonster,

Did you need to remove the charcoal canister on the passenger side (near the heater core inlet) to do this? Which of the two hoses going into the heater core did you use as an "outlet"?

(Apologies for reviving an old thread.)