Does your upper/lower radiator hoses get rock hard from just normal driving? If they are, and you are sure you have gotten ALL the air out of your cooling system, there is a good chance the HG is just slighty pushing.
Also, if you idle your car for a long time with the radiator cap off, do you get air bubbles every few seconds that wont go away?

Thats why I like metal HG's, you can have a blown/leaky gasket and still drive it hahah

 

you have the single core half radiator?

 

get a better radiator. it is not up to the task.

you can get a cheap *** alum core plastic end tank rad off ebay for 80 bucks

 

i got this one it is way sweet
no probs at all.

http://cgi.ebay.com/ebaymotors/HONDA...QQcmdZViewItem

 

I would double check all of the things you can easily.

Is the fan comming on?
Is the thermostat opening properly?
Is there air in the system?
Bad compression test?

All of these are free or $5 answers.

I picked up a cheap $50 shipped radiator from eBay. Old one was just falling apart.

 

my blackcar did this for ahwile turned out that after 10 years the factory radiator was pluged. try this go drive the car after its fully warmed up pull over and check for cool spots on the radiator if theres any coolant is not flowing there.

Beau

 

That's exactly what happened to my old radiator. There was actual sludge in the radiator. The car kept getting hot on the freeway. I put my fan on 100%, that helped a bit, but not much. Did comp test, just fine. I looked in the bottom of my coolant res, and there was this sludge in there. I cleaned everything out, got a new radiator and problem solved.

 

How do you find a cool spot?

 

Put your hand over it, does it feel cooler in some spots? If it doesn't feel so hot, try touching it, if it feels quite hot. I wouldn't touch it. Come on. Common sense.

 

thermal guns work nice too..... for those with $$$