Since the weather is turning for the colder, I had attempted to try the heat to make sure everything works correctly. As it turns out, it only throws luke warm air when the temp control is all the way on hot. Popped the hood to check the heater core line temps and one is noticeably cooler than the other. Going to flush the heater core out within the next few days hopefully. Is this a good start? Is there anything else I should do while I am at it? I will post how everything goes and the result when everything is done

 

yup, good call on core being plugged.
check fluid levels too...any "swishing" noise from dash would be low fluids, could cause the issue to.

 

Mine is doing the same except it blows hot on the hottest setting. Any other temperature settings blow lukewarm. I dont understand why it would do this either...so any help would be amazing.

 

Same here in my 2000. But no matter what setting, cold or hot, still blows cold-ish. Fluids are full, it did sit for almost 2 years so I'm getting it back up to par. Would rather not replace the heater core. Lol

 

It's hard to think of the heater today because it's over 90 here in Florida. Doing the normal radiator type flush will most likely not remove the crud from the heater core. One method we use and discussed here is to remove both heater hoses from the firewall then connect a garden hose to the heater core using clamps.
Alternate between the inlet and outlet until it's unplugged and running clean. Don't use this method if you have super high water pressure over 50-60lbs so you don't blow your core. Make sure you have a 2nd hose to connected to keep water out of the engine compartment. The first time I did this I had to alternate 5-6 times before I got it unplugged but that was when some stupid owner mixed regular antifreeze with Dextron..oh..I was that stupid owner but now I'm not anymore because I found the BlazerForum.

 

warthogdriver: definitely thought of that too since that was the cause of a no heat last year. That was when my water pump decided to take a crap.

El Diablo793: Yours puts out luke warm air even on the cold setting? I would look into the blend door actuator that is between the glove box and fire wall. A gear could be broken inside of it not allowing all the air to bypass the heater core. There are some threads on replacing this. That is one thing to look at, there may be others that have more information than that

96awd: Haha, me neither. Hoping the flush does the trick

dobyken: You hit the nail on the head there. That was the plan in a nut shell to flush the heater core

 

Haven't forgot about this thread! lol

I plan on flushing the heater core tomorrow. Not sure if I will go to the extent of taking pictures, but if you want me to, just let me know.

I will let you guys know how it goes and hopefully I have heat before the end of the day!

 

Pictures would be great! Lol

I really need to do this as well as flush the radiator still. My job at Toyota is stiff about doing stuff to our own vehicles. We have to pay almost full price for anything, even have to pay to use the lift! At Jiffy Lube, I did whatever I wanted to my vehicle for free. Miss that job but don't miss the pay. Lol

 

I had this exact problem, i just finished draining and flushing my radiator. I also took the hoses off my heater core and hooked my water hose up to the entry line and flushed it out. Heater now works great. that should be your problem.

 

Well here it goes lol

Flushed the heater core this morning and attached are a few pics that I took. Sorry that there are so few, but that is the way it goes sometimes. It was really pretty simple. The first pic is just showing the heater core lines going into the fire wall. The line on the left (as looking at it on the pic) is the inlet, and the one on the right is the return line. In the second pic, the heater core lines have been removed and two other lines were put on and snugged up with hose clamps on the metal fitting of the heater core. Both of these other lines had a fitting to put a garden hose onto it in order to flush the core out. The other lines were long enough to route the water out and away from the engine compartment. The third pic is of the garden hose fitting I was talking about. And the final pick shows the original lines put back on and I was back in business!

There was a ton of crap that came out of the heater core while flushing. It took 8 to 10 times of flushing and switching back and forth between the two hoses in the second pic before it ran clean. After the flush, I had an air compressor that I blew the water out of the lines and heater core (which is optional) but figured that then there wouldn't be any guessing on the concentration of antifreeze later. The feeling of heat coming out of the vents was a welcomed change! lol Hope this helps anyone else wishing to do the same. If there are any other questions, let me know!