OK i need some advice on this car heater problem

[TheSiege]

the car "warms up" the temp guage is in middle, which is typical
the air comes out full blast so i know the blowers are working
but the air is luke warm at best.
i have no idea what the problem is.....
i posted about this a few weeks ago
but now i have more info

so anyhelp would be great

 

[franksta]

Maybe there's something blocking the heat exchanger not allowing the air to pass through.

 

[radioouman]

Heater core is plugged.

Disconnect the water hoses going into the firewall. Connect a garden hose and flush them both directions.

Oh, drain the coolant before doing this, and it would be a good idea to get one of those cooling system cleaners that break down the deposts.

 

[quakefiend420]

Originally posted by: radioouman
Heater core is plugged.

Disconnect the water hoses going into the firewall. Connect a garden hose and flush them both directions.

Oh, drain the coolant before doing this, and it would be a good idea to get one of those cooling system cleaners that break down the deposts.

seconded

 

[leftyman]

check your radiator coolant... try partially covering your front grill with a piece of cardboard

 

[iamwiz82]

Originally posted by: leftyman
check your radiator coolant... try partially covering your front grill with a piece of cardboard

Not the problem if the car is getting up to normal temperatures. Blocking the radiator will only make the engine heat up to operating temperature quicker.

Sounds like a blockage to to heater core. I'd flush out the entire system, like radioouman said.

 

[TUKIN18S]

Heater core or thermostat. I agree that if the car is up to normal op temp then coolant levels should be ok, but it won't hurt to check.

 

[flot]

Problem could be the heater core, not enough coolant making it into the core = never gets hot.

OR

The problem could be the air blend door - there is a flap inside the heater box that directs the air either over the heater core or over the air conditioning evaporator.

Remember old cars where there was a stiff slide that you moved back and forth from red to blue? That had a cable going directly to the blend door and would move it back and forth. Newer cars use electronic controls and servo motors to reposition the door.

If you sit in the car in complete silence and turn it to "on" (but don't start it) you should be able to move your temp control from 'blue' to 'red' and hear something inside the dash moving.

 

[radioouman]

Originally posted by: flot
Problem could be the heater core, not enough coolant making it into the core = never gets hot.

OR

The problem could be the air blend door - there is a flap inside the heater box that directs the air either over the heater core or over the air conditioning evaporator.

Remember old cars where there was a stiff slide that you moved back and forth from red to blue? That had a cable going directly to the blend door and would move it back and forth. Newer cars use electronic controls and servo motors to reposition the door.

If you sit in the car in complete silence and turn it to "on" (but don't start it) you should be able to move your temp control from 'blue' to 'red' and hear something inside the dash moving.

The old cars that I've familiar with had a manual water valve to change the amount of coolant flowing into the heater core.
I believe that the door that you speak of controls the air flow to the defrost, panel, or floor.

 

[desy]

popular mechanics

 

[Phoenix15]

Originally posted by: radioouman
Heater core is plugged.

Disconnect the water hoses going into the firewall. Connect a garden hose and flush them both directions.

Oh, drain the coolant before doing this, and it would be a good idea to get one of those cooling system cleaners that break down the deposts.

I have the exact same problem. I have a 98 Blazer. Wouldn't happen to know where the hoses are would you? Do they just clamp on? So I pull two hoses off, stick a garden hose in and just let it run for a while?

 

[Ausm]

Originally posted by: radioouman
Heater core is plugged.

Disconnect the water hoses going into the firewall. Connect a garden hose and flush them both directions.

Oh, drain the coolant before doing this, and it would be a good idea to get one of those cooling system cleaners that break down the deposts.

:thumbsup:

Sounds right.


Ausm

 

[iamwiz82]

Originally posted by: Phoenix15

Originally posted by: radioouman
Heater core is plugged.

Disconnect the water hoses going into the firewall. Connect a garden hose and flush them both directions.

Oh, drain the coolant before doing this, and it would be a good idea to get one of those cooling system cleaners that break down the deposts.

I have the exact same problem. I have a 98 Blazer. Wouldn't happen to know where the hoses are would you? Do they just clamp on? So I pull two hoses off, stick a garden hose in and just let it run for a while?

Usually there are two hoses that run from the front of the engine to the back, usually on the passenger side. Most newer vehicles a have a plastic connector on one of these hoses that can be removed to see in both sides. You stick a T-connector in there that has an adapter for a garden hose and then open up the radiator cap, put in an adapter and run a hose to a huge bucket/barrel and turn on the water. Lots of lots of yucky things will come out, in my experience.

 

[RayH]

If it's an old car, you want to be careful about running too much pressure through the core with a garden hose. If the heater core's corroded, it can spring a leak and in some cars you have to pull the entire dash to replace it.

 

[flot]

Originally posted by: radioouman

Originally posted by: flot
Problem could be the heater core, not enough coolant making it into the core = never gets hot.

OR

The problem could be the air blend door - there is a flap inside the heater box that directs the air either over the heater core or over the air conditioning evaporator.

Remember old cars where there was a stiff slide that you moved back and forth from red to blue? That had a cable going directly to the blend door and would move it back and forth. Newer cars use electronic controls and servo motors to reposition the door.

If you sit in the car in complete silence and turn it to "on" (but don't start it) you should be able to move your temp control from 'blue' to 'red' and hear something inside the dash moving.

The old cars that I've familiar with had a manual water valve to change the amount of coolant flowing into the heater core.
I believe that the door that you speak of controls the air flow to the defrost, panel, or floor.

Sorry, when I say "old cars" I am thinking 1980-1995 or so, vs 95-newer which tend to have more electronic and/or vaccum operated controls.

I have only seen a couple cars with valves on the heater core - this seems like it would be much more prone to failure? On the 3-4 dashboards I've disassembled for various reasons, they all operated more or less the same way - hot coolant was always flowing through the heater core.

 

[Nutdotnet]

Originally posted by: RayH
If it's an old car, you want to be careful about running too much pressure through the core with a garden hose. If the heater core's corroded, it can spring a leak and in some cars you have to pull the entire dash to replace it.

Yup! My heater core blew out on me due to too much pressure. Entire dash had to be taken apart.

First things first though, check your coolant levels man! You may just need to ad more coolant. Don't ask me to explain WHY, but this has happened to me before. Mine was worse though, it blew cold air.

OR, like others have said, you may have a blockage. This blockage could be air (which you'd have to wonder how it got in there) or something else. A flush would be a simple fix.