I just bought this vehicle and don't know anything about cars. my honda started idling high and dont know what it could be. when i start my honda it sounds fine for a couple of minutes and then starts going to the number 4 and goes as low as 2/3 and goes back up again. one other prob which idk if it is related or just another prob itself is that it seemed to overheating but when i pulled over it wasnt out of ant- freeze/coolant or water it was actually spitting it up and spraying everywhere? this has only happened once and my car has been sitting since...
does anyone know what it could be?

 

welcome.

2. rule of thumb, can't safely remove radiator cap when it's hot; true for every car.

To me sounds like might be low on coolant, is there any in the overflow tank or in radiator when cool? If not, then --->
A) Refill radiator with pre-diluted antifreeze ($10/gal any car or grocery store) and then fill plastic overflow tank (connected by tube to bottom side of radiator cap fitting) half full [this tank you can safely open when radiator is hot, BTW].
B) Drive it for 5 miles (get it hot) and park it to cool.
Next day repeat A) and B) until rad is full and tank remains ~1/3 - 1/2 full.

1. Have had old hondas, two of them have had that idle oscillation during warm up, but it's always gone away when warm. Can't recall what was advised to me here for that, but its called something like idle air control valve cleaning, located on fuel injection unit, up high where you can get to it pretty well I think; there are good directions available.

I'd fix the coolant thing first.

luck - post back up progress...

 

Yes, sounds like a coolant leak of some sorts, Need to find the source and repair. Then be sure to bleed the air from the cooling system.,,,,see what you have from there.

UhOh-sounds like you have/had an issue with the FITV (Fast Idle Thermo Valve....or something like that). Most of the time you can pull the cover and "screw down" the "ball" inside and the issue will go away....cleaning the ports to this valve and the IAC can't hurt anything.

 

Thanks, Poorman