Some quick back story: my Civic was in the shop due to overheating and loss of power/idle going nuts and powering up from 1k-3k at a stop. I got my Civic back last Sunday - the mechanic said I had a broken PCV valve and replaced it. He also said I was low on coolant and filled it back up, which has stopped the overheating (weird, I know, further explanation below0.

Civic ran fine all of last week, but this morning on the way to work I noticed a couple of things - idle is rough at stops, feeling like it's idling too low (huffs and puffs at stops). After parking in my garage, I had also noticed the engine temp gauge had risen just slightly (just a bit above what it normally runs at). I've had an ongoing problem with my cooling system in the past year or so. At first my radiator and then one of my hoses blew, causing overheating. But lately, my coolant seems to just disappear on its own - no leaks anywhere - it just lowers over time and disappears, causing overheating.

I've read on several forums this morning that this idle issue and loss of coolant are related to either the IACV or some other parts. Can anyone help explain this to me and provide some clarity on the issue, what the problem could be, and potentially how to fix it? I just need my Civic to last me a couple more weeks before my new car arrives. Thanks!

 

Sounds to me like all those overheating toke it toll and your head gasket might have given in, if you lose coolant with no apparent leaks and you get a sweet smell when your driving you might have a bad head gasket. Do you have any other sings like white smoke or is your oil like chocolate thick brownish? all which are signs of a blown head gasket. my 2 cents.