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!

 

i'd bet you have a blown headgasket which is slowly consuming your coolant. since you only need the car a few more weeks i wouldn't bother fixing it, i mean unless you want to keep the car or plan on selling it in good running condition. otherwise just keep checking the coolant level and add as necessary.

 

it could possibly be an air pocket in the system. try bleeding it. if not its most likely a hg

 

Any thoughts on how to remedy the rough idle problem in the mean time, aside from manually setting the idle higher on the idle screw?

 

Keep the radiator and reservoir topped off with coolant at all times. If you do this and bleed the cooling system, you may be able to improve the hunting idle. But this may be only temporary as I also fear the head gasket may be blown.

 

if the resavoir is full and while the engine is running and at n.o.t open the res and with the small hose in the coolant look for bubbles or raise the revs by hand with the tb and look for bubbles, if so you gotta blown hg

 

Hey guys I got a quick question since we're on the topic of idle. My Civic used to idle a bit lower than it should have. I just replaced the o2 sensor and now it idles better but when i put the car in park it shoots from 1k to 2k drastically. Any ideas? thx