Rep Power: 0

Would this cause overheating issues? At one point some donkey mechanic installed an accord radiator in my friends civic, would this really cause problems with cooling? She's melted 2 oem (Autozone special) radiator caps, built enough pressure in the system to pop the cap off the coolant res while melting one of them. She's been going through a good amount of coolant. I've burped the system several times and the car works fine then the cap melts and she over heats.

 
Rep Power: 209

I'm not sure how you can melt a radiator cap so I don't really have any answers.

As far as would an Accord radiator cause a problem, not if it is installed correctly. Radiators are sized according to the engine so my guess would be that an Accord radiator would have a higher capacity than a Civic radiator and if the fans and hoses are working properly it should do a better job of cooling the engine.

I would wonder why an Accord radiator was installed in the first place. My guess is that there was an overheating problem and since they couldn't track down the problem they tried a bigger radiator.

 
Rep Power: 233

Classic sign of a bad headgasket. Have the coolant checked for exhaust gases.