Heater

Okay, I've replaced the heater core after flushing system thoroughly. I've replaced the coolant temperature sensor and thermostat. Took my chevy 1500 out for a spin to get coolant circulating and the heater was blowing hot as hell!!!!! After about 5 minutes, the hot air started cooling down, the heater was on HI and and the hottest temperature. I drove on some more turning the heater down a notch and turning the temperature down a notch and it started getting hot again. What is going on here or I'm i crazy?? Some please advice. If you know what could be causing this, tell me the part and where it's located.

yea mine was the same way, i think these trucks jus have some kick ass heating systems, my heat gets hotter than hell and i just have to turn it off completely even when its 15 degrees outside, i dont think anything is really wrong but im not sure

More than likely just some residual air in the system. My '98 Sub took about a week to work right. Hope this helps.

Thx guys. I've realized that I don't have a sufficient amount of antifreeze in the system. Let me try this and I'll post the results.....to be continued......

Okay guys,

As you know, I replaced the heater core thermostat and flushed my system thoroughly weeks ago. Here's my update: I've been driving my truck and the heater is still not getting as hot as it should. I turn my dial to max and it's still blowing like I have it on halfway. I changed the thermostat again today because I thought I may have bought a faulty thermostat and still the same problem. Any suggestions? HELP!!!!!!!

PS
I don't think this has anything to do with my heat but for these past few weeks, I've noticed my battery meter on the dash fluctuates between 9 and 14. It sits one notch from 9 when i turn my heater on. I know I need a battery, but could this be affecting my heat output?

Okay guys,

As you know, I replaced the heater core thermostat and flushed my system thoroughly weeks ago. Here's my update: I've been driving my truck and the heater is still not getting as hot as it should. I turn my dial to max and it's still blowing like I have it on halfway. I changed the thermostat again today because I thought I may have bought a faulty thermostat and still the same problem. Any suggestions? HELP!!!!!!!

PS
I don't think this has anything to do with my heat but for these past few weeks, I've noticed my battery meter on the dash fluctuates between 9 and 14. It sits one notch from 9 when i turn my heater on. I know I need a battery, but could this be affecting my heat output?

You could HELP us to Help you with more info on your 1500. Year? motor? etc. Since you've indicated you have a volt meter you must also have a temp guage. Is it reading a normal temp? In most cases the coolant flow through the heater core is not controlled. The temp out of the heater registers is controlled by a diverter door in the plenum. Turn it to cold and it's all outside air. Turn it to med and the air starts moving past the heater core. Turn it to hot and all the air is moving past the heater core. When the truck is up to normal temp feel the heater hoses just before they go through the firewall. They should both be about the same temp as the upper radiator hose indicating there is no blockage in the core. Year?, model? & motor? "ALWAYS".

Okay...Okay...it's 1995 chevy 1500 w/350...2wd

I'm guessing there is no blockage because the upper radiator hose and the heater core hoses feel the same and yes I have a normal steady temp on the gauge.

Okay...Okay...it's 1995 chevy 1500 w/350...2wd

I'm guessing there is no blockage because the upper radiator hose and the heater core hoses feel the same and yes I have a normal steady temp on the gauge.

OK, good job!!!! So, we're going to assume that the thermostat and the heater core are working properly. The only other thing in there is the temp control(prev referenced as the diverter door)door. Changing the heater core requires the plenum, or part of it, to be removed. Doing this MAY have upset the clearances of the temp control door, not allowing it to go to the commanded position??? Don't know if the '95's are vacuum or electrically controlled. The Temp Control Door would be what I would look at........Steve

okay...where is this located and do i have to take the dash down to get to it?

OK, good job!!!! So, we're going to assume that the thermostat and the heater core are working properly. The only other thing in there is the temp control(prev referenced as the diverter door)door. Changing the heater core requires the plenum, or part of it, to be removed. Doing this MAY have upset the clearances of the temp control door, not allowing it to go to the commanded position??? Don't know if the '95's are vacuum or electrically controlled. The Temp Control Door would be what I would look at........Steve

On my '98 Sub it's electrically controlled and the motor is easily accessed just to the right of the tranny hump. The motor looks like an upsidedown house. Take the motor off and use a pair of needle nose pliers to turn the door rod and see if there is any interference or noises while your turning the door rod. Keep in mind that this is for a '98 C/K and may not be the same as your '95. Hope this helps you man...Steve

LOL....forgive me but i have know idea what a tranny hump is or where it is?

On my '98 Sub it's electrically controlled and the motor is easily accessed just to the right of the tranny hump. The motor looks like an upsidedown house. Take the motor off and use a pair of needle nose pliers to turn the door rod and see if there is any interference or noises while your turning the door rod. Keep in mind that this is for a '98 C/K and may not be the same as your '95. Hope this helps you man...Steve

centerline of the inside firewall. If you ask me what that is, I'm done, stick a fork in me. You're up late, go to bed.........Later

thanks a lot......you were a huge help...much appreciated.

centerline of the inside firewall. If you ask me what that is, I'm done, stick a fork in me. You're up late, go to bed.........Later

I found out that my heating system on my 95 chevy 1500 is vacuum controlled and not electric. I guess my problem lies somewhere else but I'm still going to try your suggestion. Does anybody else have any suggestions?

I think i may have misdiagnosed the problem. Question: Do the two hoses coming from the heater core suppose to feel hot like the top radiator hose? If so, the hose leading from the heater core to the water pump is not even close to being hot. Does this mean I have a faulty water pump or clogged hose? I mean the hose feels a little warm but not hot like the other ones.

I think i may have misdiagnosed the problem. Question: Do the two hoses coming from the heater core suppose to feel hot like the top radiator hose? If so, the hose leading from the heater core to the water pump is not even close to being hot. Does this mean I have a faulty water pump or clogged hose? I mean the hose feels a little warm but not hot like the other ones.

Sounds like a blocked heater core to me.

By now if you've read my threads, you know I've done a lot of troubleshooting on my heating system(95 Chevy 1500). i found out I had the wrong thermostat a month ago and that fixed the problem. Well, something else is going on now. for some reason the heat is not blowing as hot as it should and i can tell it's trying to.

This is what i've noticed. When i cut the heat on, the hose running from the core to the water pump loses heat meaning before i cut it on, it's so hot that i can't hold it. When i cut it on, it becomes warm to the point where i can put my hand around it constantly. Is this suppose to happen? Another thing i've noticed is that the tank on the right side of the radiator(facing vehicle) is extremely hot and the tank on the left side is not? Is that suppose to happen? Remeber, i don't know much about HVAC so i'm learning as i go.