alphasurf

Hey fellow members,
I just recently picked up a 1996 2 door z71 tahoe 5.7 liter and she has no heat or air. Weather has been really cold here and need to figure out if its the heater core or why she has no heat. I am not an avid DIY Mechanic so this will be a good chance for me to learn with the help of more experienced DIY Mechanics.

Can anyone tell me how I can diagnose the heating system components to find out what the problem is and what part/parts need to be replaced? The blower motor goes on when I use the Heather-a/c head control. That is all I can say.

Thanks in advance to all that can help.

payne1226

check the coolant level
check thermostat take it out and boil it see if it opens and closes if it is nasty looking clean it off with some vinegar
maybe cracked block or plugged heater core lots of different avenues to go down
start with the cheap stuff and go from there


good luck

alphasurf

Thank you. I will start by checking coolant like you suggest and then move on the thermostat, then ill report back. going to have to wait until the morning.

alphasurf

Just a quick question. If it has a cracked block wouldn't it overheat? Because it drives fine and doesn't over heat.

Rednucleus

Does the dash gauge show motor coming to normal operating temperature?
Once warmed up, does the upper radiator hose feel nice and hot and hold pressure?
Does one or both heater hoses feel hot like the radiator hose?
If yes to all three then I would be looking at items associated with getting water thru the heater core, or a badly plugged core. BTW do you get nice cold A/C air when you turn on the A/C?

alphasurf

I bought the 96 Tahoe about 1 week ago from this guy who was very vague about the trucks condition. He did tell me the rear end needs to be replaced or rebuilt and he gave me 6 bearings to go with the truck. Besides that the oil doesn't smell like antifreeze. He said the a/c and heat do not work. The truck drives very good even with the problems it just mentioned. It's been raining here for three straight days now and according to the weather channel I have one more day before the rain clears up. Then I will be putting time into finding out the issue with the heat. I will be checking this thread and the day after tomorrow will be doing what you all mention so I can get to the problem with the heat. The other problems I will tackle at a later date.

alphasurf

Yes the truck warms up to normal operating temperature after about 10 minutes of idling/driving.

alphasurf

Okay I just went out there in the rain started her up let her run for 10-15 minutes and then stuck my hand under the passenger floor mat to find its all wet. I need a new heater core. I already watched a few videos on YouTube on how to change it. I have never done a heater core before but am going to have fun doing this myself. Does anyone here recommend any specific replacement heater core? I found one on parts geek for like $33.00 does it matter which one I buy?

ToolBelt2

Parts Geek has good products. Just be sure they have all your vehicle specs. e.g. Make, model, year, 2 or 4 WD, etc.

Rednucleus

Rockauto is another good source. In the "old days" you could get your core rebuilt at the local radiator shop; don't know if that's available/practical in the 21 century!