Compressor in my '08 Civic blew out on a road trip to Colorado this July. Got the whole system replaced to the tune of $1500 at Firestone. Even before leaving CO,  frost started developing on the low side lines.  Took it back to Firestone, and their advice was simply to not run the air re-circulator so much, and that it would likely break in at lower altitudes.

Fast forward to today - still dealing with intermittent issues and after driving 100 miles in west Texas, a pit stop revealed a huge collection of ice around the low side line.

I'll be taking it back to Firestone ASAP as it should still be under warranty, but what could be the cause of this? For $1500 I expect this system to work flawlessly.

Undercharged or evap coil plugged / no airflow.

Low refrgerant ... leak.

I say over charged, getting liquid back

Is the system blowing cold?

this

Spent the last 8 months diagnosing and repairing automotive ac, sounds like you are undercharged if the lowside is freezing up.

The compressor should cycle on and of. If its not then it is not uncommon for that model to need a control head. An evaporator temp sensor  malfunction can cause  that as well.

Then why isn't the evaporator freezing up?  This is a clogged air side on the evaporator with possibly low refrigerant charge.  This makes the system pressure low so the evaporator is at lower pressure when it should be just at freezing.



Remember, temperature in phase change is constant with respect to pressure.  So low charge will make lower condenser and evaporator temperatures.  In summer, you have no cooling because the condenser cannot reject heat to the environment.  



An overcharge would appear as higher condenser and evaporator pressures.  Meaning evaporator will be well above freezing.



 

It is blowing cold.  The problem is that I get less and less blower pressure as the lines freeze up, resulting in less cooling.

Firestone took the car in this pm.  They just called and said that the entire ac control computer is jacked, causing the compressor to constantly run, and will cost $310 to fix.  I said this problem has been ongoing since I got it back and was reassured that it would go away.  I'm supposed to hear back from the manager.  I'm so pissed.

Like i said in my earlier post..... its not uncommon for that model to meed a control head. Not Firestones fault.