After 177000km, intermittent CEL (solid and flashing) and some hint of gas creeping into the cabin decided to do the valve adjustment, change all spark plugs and coils. Would like to point out that sometimes the CEL would disappear for a few days, then reappear then disappear for a few - drivability was more or less the same throughout that time. Engine did have a slight tick coming from the #2 cylinder (I’m guessing) but nothing alarming to my untrained brain and ear. Bought a ODB scanner off Amazon (MOTOPOWER MP69033) and P0302 popped up during the test drive. Attached a picture of old plugs and coils (#1 left - #4 right).


old plugs and coils (#1 left - #4 right)

old plugs and coils (#1 left - #4 right)

Found all valves were tight, especially the exhaust. In hindsight I should’ve measured all of them before working on them but it’s cold here in Canada and hands were seizing so next adjustment I’ll take note. Looks like all the issues come from #2 and #3 but why no P0303? Replaced with NGK 6774, HITACHI IGC0073 and new valve cover gasket.

Adjusted intakes to 0.157mm and exhausts to 0.279mm reassembled everything and fired it up.

Everything sounded louder and even noticed some slight vibration (on engine and in cabin) during the time I left it to idle for 10min, no CEL so I’m happy with that. Majority of the noise (clicking) from the exhaust side of the engine. Is this normal? Don’t know…so left it alone for a day then fired it up again and noise and vibration levels were much less, still present but still louder prior to the service. Driving it around my neighborhood it felt more responsive but I kept it below 5k RPM to be safe. Will probably take it on a longer drive over the weekend but any thoughts or advice is much appreciated beforehand.

Overall the Fit (2012) has treated me pretty well, only wish I had done this sooner than later. Been creeping these forums prior to this attempt so hats off to ya'll for paying it forward with the knowledge.

 

Nice little bit of work. I'd also follow that up with doing an idle relearn procedure to really get that little L15 to hum along nicely. Just allow the vehicle to get to full temp, you'll hear the cooling fans cycle twice OR engine coolant temp of 195 to 200 degrees F. Once up to temp you then shut the car down and either A) Use the clear DTCs/Codes function on your scanner or B) Briefly disconnect the negative battery cable to clear the PCM. Then let the car idle for about 3 to 5 minutes to complete the idle relearn.

Now... Going from what I'm seeing and by the vehicle mileage... It seems that cylinder's 2 and 3's spark plugs were beginning to back out. Note the soot on those two coil packs and spark plugs, the location of them just above the integrated exhaust manifold flange and catalytic converter, along with recollect how easy were to come out. That's likely the noise you heard and you've gotten LUCKY that the spark plug didn't eject.

I'd also recheck spark plug torque just to make sure they're seated and not backing out again. The original spec of 13 ft.lb still allows the spark plug to loosen over time/heat cycles. The updated torque spec of 17 to 20 ft.lb (like that of the S2000) is now used.

 

Thanks for the tips Hootie. Will perform the relearn and check the torque on the plugs. Plugs went in dry, no anti-seize. After hand-tightening I gave it a rough 2/3 turn as per instructed on packaging. Certainly felt like the washers were crushed.

 

@Hootie's post sounds like good advice.

Looser valves will sound louder. Just throwing that out there. Not suggesting that your valves are too loose if they sound louder.

 

Thank for chiming in Mister Coffee.

Did the relearn procedure and seems normal for now. Was used to not hearing much ticking/clicking from the engine bay since I bought it so maybe I'm lucky it hasn't broken down yet.

Put on 50km on a test drive and figured I post a video for those looking for some reference as to what is expected when circumstance are similar. It doesn't lurch or hesitate on acceleration or deceleration like before.

 

recently adjusted my valves, was worried it sounded bad but it sounds basically like the video.