i need some possible causes for engine light.....obscure things that could cause it to go on. also after i shut off my car sometimes the coolant tank start to bubble......is that normal? heavy vibrations coming from engine at times along with surging when i take my foot off the gas....help please!!!

 

is it over heating?

 

Also you could try the paper clip method and the car will tell you why the light is going off, provided you still have a functioning conputer.

 

it tends to run at about 220.........if im in stand still traffic it might go up to like 230............also i filled up the coolant tank with 100% coolant.........i have diluted it since....but could that have done any permanent damage? what is the paper clip method? and is there a way to tell if my computer is still functioning?