I tried to replace the PCV valve on my '99 Civic EX over the weekend. I had the oil filter out and was trying to pull the hose clamp off the valve while under the car but wasn't successful so I just left it and put a new filter on. Then, while on the freeway, yesterday, I gave it the gas and immediately heard an air leak and had significant power loss. I limped the car home and it still seemed to idle fine but, after turning it off, a bunch of coolant and oil leaked out onto my driveway.

Does anyone have an idea what might have happened? I figured that there would just be a vacuum leak if the hose had come disconnected from the PCV valve and had planned to pull the intake off and get to the PCV valve that way. But now I'm afraid something has been severely damaged and I should just have the car towed to a shop.

 

Can you see where the oil and coolant is coming from? it could be 2 different leaks.

 

I just noticed your reply. For some reason I'm not getting email notifications.

I can't see where the oil and coolant are coming from. But I do see leaked coolant pooled at the base of the radiator.

I pulled "Code P505: Idle Air Control System". I'm planning to take the car down to a shop tomorrow. I plan to ask them to first replace the PCV valve and see if that is the source of the vacuum leak. I'm in horror and grief as I imagine all the things that might go wrong at the shop including an inattentive technician overheating the coolant-starved engine.

Please note that this is a very-well maintained EX which was running beautifully before I monkeyed w/ the PCV valve, so I don't even know somewhere reliable to take it. I think I may be screwed.

 

This is amazing, but it turned out that I picked up a rock in the radiator on the freeway at around the same time that the vacuum leak started. I only discovered the radiator leak when replacing it last w/e. But... wow. The two simultaneous issues sure scrambled my wits!

I'm still left w/ the vacuum leak, but at least I can get the car into the shop without worrying about the tech overheating the engine.

 

In case anyone runs across this thread, it turned out the "vacuum leak" I heard was actually coming from a hole in the muffler. Or, actually, where the pipe from the catalyzer meets the muffler. This might be a coincidence, but the P505 Idle Air Control CEL I'd had for weeks immediately went out when I started the car after patching the muffler. Crazy eights. Is there any relationship between exhaust back pressure and the IACV function? Like, perhaps, through the EGR circuit?