[SIZE=3]Hi there...I've a problem with my car...it's a 1994 nissan altima...mataas kasi un menor when i start the engine then medyo nababawasan when i turn on the a/c...the first mechanic that i consulted told me i had to change the cylinder head kasi daw may singaw na un makina...but when i consulted the mechanic from shell...sabi nya pwede pa daw un cylinder head...ano ba talaga?[/SIZE]