2012 Fit with 63k. Ok, smelled gas - found loose plugs and 2 burned coils! Replaced plugs and 2 bad coils (they were pretty brittle). A week later I found myself in limp home mode and found number 4 coil was wet - got CEL code 304. This was an original coil. Number 4 was coated in condensate (it was not coolant - clear on a towel). I swapped the old number 4 with old number 1. A few weeks later, felt like missing - inspect found condensate on number 4 again. No trace of liquid leaking in engine - but its appears to be water condensing not coolant leaking. Oil seems clean. Coolant level is stable.
This one baffles me. I was shocked to read about loose plugs on a Fit - never experienced that on any car. Now condensate?
I am figuring weak coils? I will replace the last two coils. But any experience like this out there?

 

You either have a loose plug or your valve cover is leaking out the backside and somehow oil is running down into the spark plug tube this is highly unlikely so I’d suggest checking the plug to see how tight it is.

 

Thanks. After finding plugs loose, I replaced them and two coils. The condensate issue appeared after that. Plugs are tight and properly torqued. There is no sign of leakage out of valve cover. It’s water on coil not oil. I have done a very thorough inspection and can find no leaks.

 

did you check the plugs again or are you just assuming they are still tight? Generally if they came loose they will come loose even quicker the next time until they eventually blow out completely. Condensation in that area is not common, pictures of the issue might help us determine what you’re referring to.

 

I assume that when you say coil 4 was wet you meant the part below the rubber seal and in contact with spark plug. Was the outside part wet too? This maybe a naive explanation but what if the cowl leaks after re-installation and water drips on coil 4 make it through the rubber seal? Otherwise, the presence of condensate means the plug isn't sitting right.

 

Yes, plug is tight.
The condensate was on outside of coil below rubber seal.

 

this on amazon could be used to address the condensation issue while figuring takes place. If you're certain water can't get in from outside, that could be tested, yeah?

Could unplug the coil and pour some water on the boot there and see if it passes through. If not, maybe pull the plug and check for cracks in the head/threading? It's gotta come from outside or inside.
Maybe also examine the porcelain on the plug for discoloration indicating plug blow-by/internal failure?