[turboz523]

Ok here's the background on the car:
1985 600 convertible, converted to t2 status by previous owner, has had no heat since I got it. I drove the car from kentucky to Pennsylvania that way and its been parked ever since. I drove the car a few times and noticed that coolant wasn't returning from the overflow bottle. Changed the radiator cap, made no difference. Thought I saw bubbles, in the overflow, so I replaced the head gasket, while it was apart found the heater control valve not working properly so I replaced it. Got it all back together and had heat for 1 heat cycle, then no heat again, coolant still not returning from the overflow. Found the hose going from radiator to overflow not fitting correctly on the tank so I ran a hose directly from the radiator to the bottom of the tank, at the same time I replaced the thermostat with a 180 with a vent hold drilled in it, and also I took the hoses off of the heater control valve and used a garden hose to try and flush the heater core out, didn't get alot out, but didn't seem like it had a good flow through it either. Put it all back together and coolant is now going in and out of the overflow like it should, but barely any heat at all now. I'm wondering if the garden hose forced something into the heater core to block it up completely? Is there a chemical I can put into the heater hoses and leave sit to try and dissolve a blockage? I'm not ripping the whole dash out of this car after all the stuff I've already done.

 

[impuresoul2k3]

Warm the car up, turn the heat on, and feel the two hoses going to the heater core, both should be hot.

 

[turboz523]

they both get "warm" but not hot. I'm mainly wondering if there's something I can put in there, a cleaner of some sort, so that if there is a blockage, it'll loosen it up so I can flush it out again and go from there. I'm also thinking about eliminating the heat control valve altogether

 

[NAJ]

If both hoses are he same temp(cool) the problem is a cold running engine or air.
Your heat will not be as it should with a 180 stat and did you place the bleed hole you drilled at the 12 0'clock position?
Also are the hoses from the valve to core correctly installed(inlet to inlet) and heater control vacuum is correct.
If you want to flush use a chemical flush(liquid recommended) and install a Prestone flush kit.($5.00 at Walmart)
Since you converted I am not sure of your setup but here is a pic of the water valve and hoses.

 

[turboz523]

what is clr? I've seen it refered to on here but don't know what it is.

 

[NAJ]

It is a household chemical sold in any supermarket/discount store for removing Calcium, Lime, Rust (CLR)

 

[charger R/T]

I saw another thread not long ago about filling the core with CLR and letting it sit others chimed in and said it works to clean it out. Then a good flush with a hose to get it out. What size hole did you drill into the thermostat? 1/8 inch is too big 1/16 inch is about right. On a cold day 1/8 could cut your heat down too much.
Tim