I have a 06 honda civic hybrid. rattle when cold.I have a rattling noise when accelerating, especially when going up hills. I heard it could need a valve adjustment. also a idle air control valve heard this could cost big money.

any help with rattle.

car has 171K on miles.

thanks,
kross89

 

Rattling or pinging sound? I've heard pinging when the cylinder heads get full of carbon. That's when you switch to a higher octane fuel to offset that until you can find a way to clean out the carbon. If it's pinging, I would try adding fuel cleaner to the next few tanks to see if that helps. If it's a rattling sound, that's a different animal from what I'm talking about.