Rep Power: 0

Hey guys, I've been following this site for a few months now after I got my new civic back in December and I just wanted to ask you guys a few questions. I own a 2003 Honda Civic EX Coupe 5-speed and I have a few overheating issues lately. Well, more like since I bought it. But anyway, The car runs great otherwise but on a few weird occasions, let's say less than 5, it will start overheating unless I'm in the middle of driving it, so like at lights, stop signs, and when I'm slowing down, the temperature gauge jsut starts going up, up, up until it's almost peaking. I've gotten the thermostat replaced and I've made sure it's had plenty of Coolant, so I have no clue why it's wanting to overheat on these weird occasions. Also, I might add that the engine light did come on a few weeks ago but shut off again after a week. Took the car into an O'Reily's Autoparts store to get the engine light checked out and it was a code: P0128 Cooling System Malfunction. I'm honestly stumped right now. Help me out?

 
Rep Power: 518

P0128 is USUALLY caused by a bad thermostat, operating temperature too low. Could also be low coolant, bad temp sensor, or other things.

Overheating......I'll say 'head gasket', just because it's a 7th gen.
Coolant in the radiator goes low or airlocks elsewhere in the cooling system, while the reservoir overflows.

 
Rep Power: 257

could be leaves or debris between the radiator,air in the system bleed it,a bad fan not turning on when stopped make sure it turns on,a bad radiator cap wouldn't allow coolant to flow back and forth between the overflow tank or keep atmosphere,leak in the system have it pressure tested, also whats mentioned above.

 
Rep Power: 292

Question:
Does your temp rise when you turn on the heater?

I'd put my money on a leaky/cracked hose...and/or faulty headgasket.

 
Rep Power: 314

^This guy knows what's going on.

 
Rep Power: 0

If it's intermittent it sounds like a head gasket.

 
Rep Power: 314

So much win in this thread.