86 civic dx overheating why???

[JJSPEC Racing]

Radiator may be clogged up. I know you flushed it, but there is only so much that will do for you. May want to pull it and send it to a rad shop to be "rodded out" as it probably is a brass radiator. Or better yet put a new one in it since that one is pushing 25 years.

[scttydb411]

Radiator may be clogged up. I know you flushed it, but there is only so much that will do for you. May want to pull it and send it to a rad shop to be "rodded out" as it probably is a brass radiator. Or better yet put a new one in it since that one is pushing 25 years.

^^^this

if the car runs ok temp @ idle, but hot when driving (esp highway) the rad cannot flow much anymore. getting it cleaned out can work, but honda rad material is so thin you may end up w/ a hole when it's all said and done. plus, honda rad are pretty cheap. make sure the fan isn't wired up backward stalling the air coming through while you're moving.

[Marta Mike]

^^^this

if the car runs ok temp @ idle, but hot when driving (esp highway) the rad cannot flow much anymore. getting it cleaned out can work, but honda rad material is so thin you may end up w/ a hole when it's all said and done. plus, honda rad are pretty cheap. make sure the fan isn't wired up backward stalling the air coming through while you're moving.

Im going to agree. I had the same problem at work. A flush wont always fix a clogged radiator. With the age, time, and driving of the vehicle Id go ahead and replace it. I replaced a fan, thermostat, coolant flush, and it was still over heating. I replaced the radiator and all was fine. But if youve been running it hot which apparently you have since u said it ran like crap when hot, your head gasket may have issues now to. Leak down test would answer that question.

[78f150boi]

how do i do a leak down test?

Im going to agree. I had the same problem at work. A flush wont always fix a clogged radiator. With the age, time, and driving of the vehicle Id go ahead and replace it. I replaced a fan, thermostat, coolant flush, and it was still over heating. I replaced the radiator and all was fine. But if youve been running it hot which apparently you have since u said it ran like crap when hot, your head gasket may have issues now to. Leak down test would answer that question.