2001 silverado heat

[icefishingnut58]

Hi

I have a 2001 chevy silverado that doesnt heat up like it use to. The temp gauge does go up to 190 degrees. But the heat just seems to be very little coming out of the vents. last winter I changed the themostat and the water pump. any ideas on why this is not warming up. I took it for a ride tonight it is 11 degrees outside i drove 10 miles and just barely warm coming out of the vent. If i put it to defrost doesnt seem to be heating much at all. it use to get very nice and warm in there even on very cold days. anything I can check?

thanks in advance

gs

[MT-2500]

Originally Posted by icefishingnut58

Hi

I have a 2001 chevy silverado that doesnt heat up like it use to. The temp gauge does go up to 190 degrees. But the heat just seems to be very little coming out of the vents. last winter I changed the themostat and the water pump. any ideas on why this is not warming up. I took it for a ride tonight it is 11 degrees outside i drove 10 miles and just barely warm coming out of the vent. If i put it to defrost doesnt seem to be heating much at all. it use to get very nice and warm in there even on very cold days. anything I can check?

thanks in advance

gs

Coolant level good?
Is stat bringing engine up to 195 degrees.
Check with a thermometer.

How many miles on it and has coolant ever been flushed?

Check heater hose for being hot to touch.
If not check and back flush heater core.
It could be plugged up.
auto matic or manual heater controls?
Is your air temp heater door changing good from cold to hot?

Post back what you find there.

[icefishingnut58]

Originally Posted by MT-2500

Coolant level good?
Is stat bringing engine up to 195 degrees.
Check with a thermometer.

How many miles on it and has coolant ever been flushed?

Check heater hose for being hot to touch.
If not check and back flush heater core.
It could be plugged up.
auto matic or manual heater controls?
Is your air temp heater door changing good from cold to hot?

Post back what you find there.

The coolant level is good. the gauge is reading 195 degrees however i didnt check it with a themometer. there is no radiator cap only the overflow. it was flushed last winter. and there is 160,000 miles on it. I will check the heater hoses tomorrow for being hot. I believe it has automatic heater controls. has the heat know you turn for red and blue which changes from cool to heat. How do you know if the air temp heater door is changing from cold to hot. can you see it to check it?

[MT-2500]

Originally Posted by icefishingnut58

The coolant level is good. the gauge is reading 195 degrees however i didnt check it with a themometer. there is no radiator cap only the overflow. it was flushed last winter. and there is 160,000 miles on it. I will check the heater hoses tomorrow for being hot. I believe it has automatic heater controls. has the heat know you turn for red and blue which changes from cool to heat. How do you know if the air temp heater door is changing from cold to hot. can you see it to check it?

Sounds like you have regular Ac/heater controls.
But a good engine/body computer capable scanner should show some heater controls operation or even set a code if there is a problem also it will show the actual engine running tempt.
No you can not see it sitting in drivers seat.
You will be in luck if you can see it standing on your head looking under dash.
It should be in middle part of AC/Heater box but they usually make where you have to pull dash to get to it.
Sometimes you can remove glove box and lower covers and radio and heater controls and look in there and sometimes see into get to it.

But first confirm both heater hoses are hot and both rad hoses are hot to touch and do not depend on dash tempt gage.
Get a Timothee on the engine and check actual running tempt.
With engine running at 195 to 200 degrees.
Then make sure it is changing to all modes and blower is working good all speeds.
Also if a cabin filter equipped check it.

A good quick check on tempt door motor and control is to switch from cold to hot and see if you can feel good cold and then good hot air coming out.

Post back how all of these checks go.

[j cAT]

Originally Posted by icefishingnut58

The coolant level is good. the gauge is reading 195 degrees however i didnt check it with a themometer. there is no radiator cap only the overflow. it was flushed last winter. and there is 160,000 miles on it. I will check the heater hoses tomorrow for being hot. I believe it has automatic heater controls. has the heat know you turn for red and blue which changes from cool to heat. How do you know if the air temp heater door is changing from cold to hot. can you see it to check it?

did you remove the heater hoses at the engine, then flush out the heater core ? this must be done in our cold climates for maximum heat, when replacing the coolant.

If the heater hoses are not BOTH hot this is the problem a restricted heater core...

the temp control motor or a stuck damper will not effect the heater hoses temp as the hot coolant always flows thru the heater core and the design of the core acts like a filter which then gets restricted..

over time heat is gradually reduced..

normally if the damper is the issue it will be intermittent and suddenly you lose heat.. damper motor is at the hump in the air box..controlled by 5volts dc..remove the motor make sure the damper control moves easy and no debris resticting its movement which all goes back to do you have a cabin filter ? no filter means issues with this and hvac performance.


just to be sure on this issue ...engine cold ,,,, remove the coolant pressure cap. start engine . run until at normal engine temp which is 187 deg f. then rev engine to 2,ooo RPM..this is how to remove air from the coolant which is a posibility of heat loss ...

when it gets below 20 deg f I place a stiff plastic sheet covering the lower half of the ac condenser.. this insures max heat when the blower is on max ...my engine temp drops when below 20 deg f with max blower speed..

also it reduces corrosive salts from entering the engine compartment..

[kenny-1907]

You said that it was flushed last year, by this did you mean the heater core? If so it may need to be flushed again. I used to have a 2000 Silverado and it had the exact same symptoms which turned out to be a clogged heater core. Had it back flushed and everything was fine until the next winter, approximately one year. I had it checked out again and again the heater core was clogging up. That time when they back flushed it they changed the coolant with the regular green stuff and I'll tell you, it never had better heat and I did not have another problem with it for the rest of the time I owned it.

[icefishingnut58]

Ok tonight I took it for a ride and got it up to temp same thing therer was warm air coming out of the vents but not hot air to warm it up like in my car. when I got home i checked the heater hoses. one was hot not wher i couldnt touch it but hot when i held it tight the other one was just luke warm. So the heater core is proably plugged? and yes i do have cabin filters and i did change them last year also. Now how do I backflush this? Just take off the heater hose and run water through them? with hose pressure switching from one hose to the other? or do you recommend to bring it in and get it flushed because of the temp outside? when i had the raditor flushed last year i had brought it in to have it done i didnt do it myself.

thanks
garys

[j cAT]

Originally Posted by icefishingnut58

Ok tonight I took it for a ride and got it up to temp same thing therer was warm air coming out of the vents but not hot air to warm it up like in my car. when I got home i checked the heater hoses. one was hot not wher i couldnt touch it but hot when i held it tight the other one was just luke warm. So the heater core is proably plugged? and yes i do have cabin filters and i did change them last year also. Now how do I backflush this? Just take off the heater hose and run water through them? with hose pressure switching from one hose to the other? or do you recommend to bring it in and get it flushed because of the temp outside? when i had the raditor flushed last year i had brought it in to have it done i didnt do it myself.

thanks
garys

both hoses must be hot ...yes the heater core is plugged.

when these auto shops flush your system they do not remove the heater hoses at the engine and flush out the heater core. this is why you and many others are suffering from low heaT....

YOU NEED TO DRAIN THE RADIATOR... then remove the heater hoses at the engine then using air pressure or a water hose flush/blow out the crap....then reverse blow...with the water blown out connect up the hoses then use my air purge fill method to add coolant and get the air out..

you will see alot of heat I run at 50 % heat temp after the engine has been running 15 minutes feet get toasty...

with temps below 20 deg f cover 50 % of the radiator / condenser with a stiff piece of plastic cut so the lower half is covered...

[icefishingnut58]

Originally Posted by j cAT

both hoses must be hot ...yes the heater core is plugged.

when these auto shops flush your system they do not remove the heater hoses at the engine and flush out the heater core. this is why you and many others are suffering from low heaT....

YOU NEED TO DRAIN THE RADIATOR... then remove the heater hoses at the engine then using air pressure or a water hose flush/blow out the crap....then reverse blow...with the water blown out connect up the hoses then use my air purge fill method to add coolant and get the air out..

you will see alot of heat I run at 50 % heat temp after the engine has been running 15 minutes feet get toasty...

with temps below 20 deg f cover 50 % of the radiator / condenser with a stiff piece of plastic cut so the lower half is covered...

Icat
one more question. instead of draining the radiator could I just take the heater hoses off the firewall and blow air through it there? Just thought it would be alot easier or dont you recommend that?
gs

[4x4junkie]

the reason for draining the radiator and then flushing out the heater core is to remove any foreighn debris in the coolant which will help to prevent from stopping the heater core back up in the near future. Fresh coolant will help to ensure that the issue doesnt reoccur....

[icefishingnut58]

Originally Posted by 4x4junkie

the reason for draining the radiator and then flushing out the heater core is to remove any foreighn debris in the coolant which will help to prevent from stopping the heater core back up in the near future. Fresh coolant will help to ensure that the issue doesnt reoccur....

But i just had it flushed last year that is why i thought just do the heater core?

gs

[4x4junkie]

it is possible to do just the heater core, i have done this many times over the years to many different vehicles, however if there is residue in the cooling system it is possible that you may have to do this again sometime soon. that the reason for recommending cleaning the whole system.

[MT-2500]

Originally Posted by icefishingnut58

But i just had it flushed last year that is why i thought just do the heater core?

gs

What ever works best for you.
Just get heater core flushed good so you can get heat is main thing now.
One word of caution be careful if you use water hose pressure to flush core.
Some water systems have high pressure that can blow heater cores.
Do not go over 20 lbs of water pressure and use caution with air pressure.
I have found out that after blowing/flushing out heater core.
Reversing the heater hoses on heater core for about a week will help aid in cleaning heater core.
Let us know how it goes.
Good Luck

[j cAT]

Originally Posted by icefishingnut58

Icat
one more question. instead of draining the radiator could I just take the heater hoses off the firewall and blow air through it there? Just thought it would be alot easier or dont you recommend that?
gs

the connections at the heater core WILL break ..do not disturb these ...use 5 gallon bucket and drain the radiator..

make sure coolant is clean..if not don't use...then drain /reverse flush into another 5 gallon pail ..this is to see how much debris was in the heater core ,, continue to flush/blow until clean...the hoses still connected to the heater core allow you to direct this flow / drain into a container..


just remember 15 psi is all you must use ...with a blocked heater core the pressure would rise too high , if you used more than 15psi of water or air to clean ..

I use 65% dexcool with 35% distilled water ...use of non dexcool gm approved products will cause damage and cooling issues ...

IF IT SAYS GM APPROVED DEXCOOL ITS DEXCOOL ! compatible coolant is not to be used ...........

[icefishingnut58]

Originally Posted by j cAT

the connections at the heater core WILL break ..do not disturb these ...use 5 gallon bucket and drain the radiator..

make sure coolant is clean..if not don't use...then drain /reverse flush into another 5 gallon pail ..this is to see how much debris was in the heater core ,, continue to flush/blow until clean...the hoses still connected to the heater core allow you to direct this flow / drain into a container..


just remember 15 psi is all you must use ...with a blocked heater core the pressure would rise too high , if you used more than 15psi of water or air to clean ..

I use 65% dexcool with 35% distilled water ...use of non dexcool gm approved products will cause damage and cooling issues ...

IF IT SAYS GM APPROVED DEXCOOL ITS DEXCOOL ! compatible coolant is not to be used ...........

Well I took off the lines at the water pump and blew out with air 15psi as you mentioned. not much of anything came out. I blew with my mouth on the hose and it was not blocked could feel the air on the other hose. Im beginning to think that as you said take the cap off cold engine let get up to temp and rev the engine to 2000 rpm was all i would have had to do. because after i did that both lines are now hot. question the one line on the water pump is a single then the other one tees off to the heater core and the overflow tank. the hose to the heater looks like a plastic ring on it i tried taking it off there but wouldnt come off. so i just took off the whole tee and blew it out there. does that line to the heater core come off? thanks everyone for all your input! and have a great Holidy season!!!

gs