Heater Core Clogg?

[silvershakenbake]

So heres the deal...

 

Vehicle: 2005 Legacy gt

 

Background:

 

I just had my mechanic go through my motor because oil consumption and head gasket issues. We foud a craked ring land in cyl 4 and replaced that piston along with pretty much all gaskets and seals.

 

We noticed a lot of build up in the engine and suspected that the previous owner had put in head gasket sealer. We decided to throughouly flush out the heater core as my passenger side heat was not blowing very hot and ended up getting a ton of gunk out that looked like the stuff in HG sealer. I spend many hours pushing water through the hoses and blowing air through them to do this until barely anything would come out.

 

Problem now:

 

Drove the car for about 10 minutues and let it get fully hot then let it cool and topped off the coolant. Ran the car for about another 30 minutes (ran great and heater worked great). While running it I did notice some girggle in the dash and when I checked under the hood i noticed that the overflow was almost full and it was bubbling (almost like it did before the repairs, but not quite as much bubble). I also noticed a slight cloudiness in the coolant.

 

It seems like there is something going on with the heater core, but it doesnt make sense since its blowing great and there is hot air. I will be flushing it again in the next few days in hopes that the problem goes away.

 

Question:

 

Has anyone had a similar issue? Ive read up on many stories about the passenger side heat not working like mine did before the repair, but now that the heat is working fine I am having a hard time understanding why there is bubbles and the overflow is filling up.