I've been reading quite a few posts about blocked heater cores from the dreaded "previous owner bars leak, stop leak product" debacle. And random heater core failures.

Just wondering if anyone has had an issue with it only partially being blocked which would cause low heat in the cabin while driving.

The rundown:

Coolant is full, bled several times, no air pockets each time. Not losing coolant at all.
Operating temps are fine, SG-II readings from 182-193 while motoring.
Both heater pipes leading into the cabin are hot to the touch.
Heater core seems to be holding heat, I'm assuming because the exterior of the heater core (where the two screws hold it in place) is hot.
When the fan is not on, there is a bit of heat coming from the vents, but once the fan is turned on, the heat dissipates. The higher the fan speed, the faster it loses heat until it's cold.

At best, fan is set to 1 (manual controls) and heat controls are pegged to max and it's warm, until it begins to cool down, where I shut down the fan, wait for heat to build and then go back to the "1" setting.

I did take out the cabin filter. It was filthy and tested it without to no change.

Thoughts and theories? I'm leaning to the heater core but I don't want to purchase a new core and seals, go through the mess that is of draining coolant and it not fixing the issue. It's starting to get cold in the Northeast.

 

I just replaced a heater core for the same problem.
Old core was partially but not fully blocked.
New core fixed the heat problem.
Fairly easy to change,there is a cover next to the accelerator pedal to access the core.

 

Yeah, I've taken it out before. So looking forward to spilling coolant in the driver's footwell again.

Thanks, I just wanted someone to confirm that they had the same issue coming from the idea of a partially blocked heater core.

 

I'm interested in hearing if the heater core fixed your problem, I have the same symptoms

 

I'll keep you posted. Sadly, it'll be a few weeks before I have the opportunity to take care of it. But I'm pretty sure that's the case of the wonky heater core.