Plugged-up heater core

My car is putting out very little heat the past couple weeks.
Engine temperature is rock solid on the gauge and heats up quickly, but the heat isn't getting into the cabin.

With it warmed-up I felt the heater hose at the firewall and one is hot, the other only warm. What plugs up a heater core? Floating crud from dirty coolant, or does corrosion build up? Either way--any hope of clearing it out with a flush?

Car is a 2003 Aurora with 196,000 miles. Runs great but it's at that point in life where I have to decide whether to continue to maintain it, or move on to something else.

 

My father is having the same problem with his Dodge p/u truck. For some unknown reason.... they have the heating system split in two halves. Drivers side blows thru one half of the heater core and the passenger side thru the other side. The passenger side is blazing hot while the driver side is cool.

I disconnected the water lines to the heater core and flushed thru it backwards. It helped the situation but did not cure it completely. Heater core replacement is the recommended repair but can be very tough to get to. On his truck.... the bulk of the dashboard needs to be removed for replacement. Extremely poor designing. Not sure what kind of job it is on your vehicle.

 

They are just small radiators, they corrode when coolant is weak, chances are backflushing won't do much but it's easier than replacing.

They are an easy repair, but you have to get to them and that can be real PITA!

 

Thanks.
I replaced a core sometime in the past. Fairly easy job on that one but an Aurora is a different animal. The heat & AC lines go thru the firewall near the center so I don't imagine it's designed for easy replacement.

Warm-ish days ahead... Maybe I can take a shot at flushing it before snow falls again.

 

Exactly. On my fathers truck..... the heater lines are in the center. That spells trouble.
The A/C evaporator looks easy to change.

 

I just went through this exact thing with the ex's Olds Bravada. Heat gauge near center and heater hoses "seemed" hot and warm to me - has to be heater core is plugged.

People she got it from said change the thermostat. Easy job and that did it, heater is back to normal.

I'd try that first.