I've got a 93 honda civic. It overheats when running on the freeway and on the road. I've checked the fluid level, its all good. I'm flushing the system on Friday. I replaced the top hose and the thermostat already. I can't figure it out. No smoke (other than normal) out of the rear. Oil looks fine too. Thanks for the help.

Check for trash that might have collected in front of the radiator, blocking air flow. If the car has A/C, the condenser is in front of the radiator, and the trash build up could be between the radiator and condenser, making it hard to see. Since you have done the hoses and thermostat, it is possible you might have blockage in the radiator, which would require rodding or replacement. Good luck.

No trash. Will look into seeing about a new radiator. I work at a collision shop so I think I can get agood deal. Any easy way of cleaning out a radiator?

No easy way to do a proper job. Remove radiator and take to shop where they remove side tanks and shove rod through cooling lines.

I agree with Dr D. In the future, use only a 50/50 mixture of antifreeze and distilled water. Minerals in tap water and well water cause major problems over time. It may be easier and cheaper to buy a new radiator. The composite tops on Denso radiators tend to crack, anyhow, around 150,000 miles.

http://www.partsamerica.com/ProductList.aspx?PartType=31&PTSet=A&SearchFor=Radiator

Its at about 190,000 right now. I've been using 50/50 atifreeze/water with soft water. So not sure. I'm getting a new raiator. Hope that fixes it.

I think a new radiator will solve the problem. I believe soft water still has rather high concentrations of salt, which when heated could be less than ideal. I would still only use distilled water.

According to a report by the University of Kentucky, softened water also increases the potential for leaching heavy metal from pipes, solder, and plumbing fixtures. Increased levels of copper, lead, zinc, and cadmium are found in soft water, particularly when it stands overnight in the plumbing system.

Radiator seemed to fix it for now

Thanks for the update!