2000 Silverado 5.3 Heating Problem

[loki31]

Hey guys,

I have a 2000 Silverado LS 5.3, in which I am having a problem with my heater. I first noticed the problem the other morning when I tried to turn my heater on, for the fir fost time in 10 months or so, and found nothing but cold air coming from the vents. So, after a little research, I flushed my heater core, checked my coolant levels and have had no joy in resolving my problem. My temp is normal when driving my truck and my AC seems to be working fine, just no heat, nothing but cold air. Does anybody have any other suggestions for me, any will be much appreciated? Thanks

[txab]

If you have hot water flowing through the core then that leaves a blend door problem, not allowing air from the core to reach inside

[pistonslap]

I had the same problem a while back on my 2000. I purged the air out of the cooling system and it made quite a difference. I never noticed any air escaping noises but it made a difference. It is still not as hot as it should be tho.Try turning your key on accessory without the motor running and move the temperature control.You should here movement under the dash.What is your motor temp?

[loki31]

I hear some movement while shifting the levers, not sure if opening all the way, or if I am just hearing the motor trying to open the blend door. In order to actually get a visual on the blend door,do I have to remove the dash or is there a way to see thru the glove box? My truck is running right at 200-210. I also tried removing the cap on the coolant and starting to see if that would help any, in which it didn't.

[ChevyTech77]

Have a block test done on the cooling system. Could very well be a cracked heat/poor sealing head gasket causing air to get into the cooling system and air lock the heater core.

[loki31]

Thanks chevytech77, I'll do that asap. So, i'm not feeling any heat on either hose at the firewall, is that indicative to a poor head gasket seal? Also, i am hearing a whining sound when I first start my truck, thinking it's the water pump I'm hearing??? possible? and how long should it take my truck to get warm to 200-210? It's taking a bit of time to hit 200 and I am in San Diego (59 degrees right now)? I appreciate all the help from everybody, this forum is awesome...

[ChevyTech77]

Could be a pump, could be a thermostat. Shouldn't take but a few minutes of driving for it to reach operating temp but it all depends on how the vehicle is driven and ambient temp also.

 

I'd have it checked for the combustion gases in the cooling system first though. Seen more of those than anything. Most water pumps are leaking before the bearing is making noise.

[loki31]

Huh, it's taking well over 15min to warm up to 190-200... So, that's definately a problem there. Is there any way for me to check if there is combustion gases in the cooling system, or is that something I'm safer having done for me? A little strapped for $$$, so anything I can do on my own, I am willing to give a shot. Once again, I really appreciate the advice.

[ChevyTech77]

Just take it in to a reputable shop that has the equipment. The test only takes, literally, 5 minutes to do. Not every shop is going to have the equipment but most these days do. Make sure the truck is good and warmed up when you

take it in. I'm sure you could do it on your own if you had the equipment but the last I checked, the kit is near $300.

Not worth it for the DIY'er.

[txab]

Napa sells a kit for about $35 for the DIYer. Can be used many times

[ChevyTech77]

Napa sells a kit for about $35 for the DIYer. Can be used many times

Got a link?

[txab]

Part #700-1006.

 

approx. $42

[ChevyTech77]

Sweet, thanks. Mine, at home, is looking kinda homely and I'm obviously (not now anyways) gonna bother

spending my money with the tool truck man!

[onthewater]

Gentleman...I have been having the same problem with my 2000 Silverado 4.8. Did you ever solve your problem, and if so what was the issue? My heat works sometimes, and sometimes does not. I do have some occasional coolant loss, so I am wondering if I have a head gasket leak and am blowing coolant as well as getting air in my cooling system. I have already flushed my heater core, replaced my thermostat, and checked my water pump...all good. I have 157,000 miles on this thing, and it still runs strong, but I need heat here in Ohio in the winte! Any suggestions are appreciated!

 

 

 

 

Hey guys,

I have a 2000 Silverado LS 5.3, in which I am having a problem with my heater. I first noticed the problem the other morning when I tried to turn my heater on, for the fir fost time in 10 months or so, and found nothing but cold air coming from the vents. So, after a little research, I flushed my heater core, checked my coolant levels and have had no joy in resolving my problem. My temp is normal when driving my truck and my AC seems to be working fine, just no heat, nothing but cold air. Does anybody have any other suggestions for me, any will be much appreciated? Thanks

[badass56]

just had this problem on one of our company trucks, changed out the rheostat and it was cured!