No heat in front of 03 mdx

[lisa23]

Hi i have a 2003 mdx that has no heat in the front but the back works fine....took it to a mechanic who said the problem was the radiator replaced that and thermostat still no heat in the front..very fustrating any suggestions please???

[proman]

It should have nothing to do with the radiator. The shop just want your money.

I would suggest to check if the blower assy, especially the door control mechanism, is working fine.

[lisa23]

proman your probably right cause now they are saying the heater core is no good... can you tell me where the blower assy and the door control mechanism are located or where i should be looking??? thanks

[proman]

Ok, first of all, I am no expert, but I would like to remind you be aware of whoever is working on your car, since they replaced totally unrelated parts. Since you still have heat in the back, that clearly indicates it's not the thermostat. The only reason to replace it is when your engine is running on low temperature. As for the radiator, it's not even remotely related.

Normally the "heater core" means the heat exchange component. Where the heated coolant flow thru and heats it up. It's not common for it to fail.

The "heater unit" encloses the "heater core" and has some mechanisms to control certain doors to route the air flow. One door called "air mix door". Which controls how much air flow thru the hot/cold side. That could be the culprit. If the motor is dead, or some component failed, leaving the door stuck open for cold air, then you have no heated air.

When I said the blower assy, I actually mean the heater unit, since they are kind of all connected together. The heater unit is located inside the center console. It's not easy to access or repair.

Hope the explanation helps and good luck.

[proman]

Another image that shows where the doors are. FYI.

By the way, to replace/repair the heater unit, they need to remove the dashboard, drain the coolant, and service the AC system. I believe the price will not be low. For the AC system, must have a certified mechanic.

[proman]

Another possibility is the water valve that controls the water flow. But I am not sure if the coolant to the front and rear heater core is controlled by the same valve. If yes, then it's not the valve.

That one is not expensive at all, should be about $20 for the parts. So you can start from there. The valve is close to the firewall on the passenger side. You will see 2 hoses goes into the firewall, and the valve is on one of the hoses.

[leec]

sorry for the long delay but i finally got it fixed and did it right at home the heater core was clogged so my brother did a flush thru the heater core and the heat is working fine now...thank goodness i didnt go any further with the service station what crooks lol....thanks proman for all your feed back..really appreciate it..