95 Civic DX Coolant Loss & Rough Idle

[Fiq]

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!

[stateofjustin]

Uhhh... The IACV doesn't cause coolant to mysteriously disappear. Coolant being drawn into a cylinder from a blown head gasket will though. and it can cause an idle issue from disrupting combustion, and cause overheating either directly or indirectly. A PCV valve is an emissions item, it has no effect on your car's temperature. if you just need the car to last, go easy on it and keep the coolant level up. No guarantee the problem won't get worse and the head gasket lets go. I wouldn't let the car above normal temp at all.

If you can't find a visible leak anywhere (check all hoses, radiator seams, smell your air vents in the car with the heater on, check the bottom of the timing belt cover), that is where it is going. Your spark plugs should tell you too, pull them and look at them.

[nerofotia]

If your head gasket is the cause of an internal coolant leak, your coolant is

a) blowing out your exhaust pipe as vapor. (This is also bad for your catalytic converter, if emissions tests are a concern in your area).
b) getting into your oil. (You can take a look at your oil dipstick to check that- if it looks like a chocolate shake...bad news, pal.)

It's cheaper to replace a bad head gasket than it is to fix all the problems that will stem from not fixing it. Fix this sooner rather than later.