Bone stock 1995 Honda Del Sol S – 120,000 miles
On my way home in this wonderful near 100 degree heat, my temp gauge suddenly shot up and I saw the small puff of steaming hot coolant billow out the back. After coasting to a stop and popping the hood, I found coolant had blown all over the front side of the engine. I nursed it home (3 miles or so) by stopping to cool and coasting a lot, then let it cool down and do it again.
I found the radiator cap was nothing but the steel outer ring and a small chunk of rubber, with the spring just hanging there, waiting to drop. After a quick trip to the neighborhood parts house, I thought the problem might be solved. But...
Two things I noticed:
1. While it took its normal forever to warm up and still didn't push over the halfway mark until I ran the AC too, I could feel no heat or pressure in the radiator hoses. Would this indicate a dead water pump?
2. At idle with the AC off, there is a surge of 300-500 rpm that only stops when the ac is turned on or the gas pedal is feathered. What in the world could this be?!?
Anyone know a reasonably priced reliable mechanic near Cary/Morrisville, NC?? While I have done teardown/rebuild operations before on American cars, air-cooled VW's, and motorcycles, I'm not sure I'm equipped for heavy duty work...

 

Any suggestions on where to begin?

There's no water in the oil, no leakage anywhere from the engine side or the radiator itself.

I'm headed to the garage to bleed the coolant system and see if that helps the problems.

PLEASE help!

 

try cleaning the IACV and FITV, then bleed the coolant sys.

cleaning the iacv
https://honda-tech.com/zerothread?id=1575913

cleaning the fitv
https://honda-tech.com/zerothread?id=1564019

 

Have you tried simplw stuff like the thermostat? Is the fan coming on at all?