Here's my chronology / info.

• 80K miles (doing about 8K miles / year), great daily driver for us even if lower miles.
• 4 mos ago, had CEL for misfire on cylinder 3 - coil and loose spark plug issues
• Repair done (dealer): Helicoil (or possibly Time-Sert) and new plug, valves gaps adjusted etc
  • (they didn't warn me much how this repair might not work, but anyway...)
• Worked ok until a few days ago -- return of to CEL & misfire on cyl 3
• Now we're at: either a new head or more likely rebuilt engine (12/12 warranty)

I only now understand how much an issue these loosened spark plugs are. My big concern: if I drop major coin to get a new motor I'm still not getting away from this problem, maybe during warranty maybe not. What should I do? No emotional attachment to the car. Thinking about getting another Honda (late-model CRV with room to run on warranty given low miles we're doing). How best to monetize the car in its present state if at all?

Thx. (And I should have hung around here a bit more to know about the risk hanging over me on this thing.)

 

That stinks. I’m surprised to hear the problem recurred in the retreaded cylinder.

I’ll leave it to others how to fix it or if, but clearly the car will be worth more running. You said new engine .. is that cheaper than a head?

A motivated person can change a head but I don’t envy the effort.

 

It’s a “rebuilt” engine- so apparently that is cheaper all things considered than trying to get the problematic cylinder back to condition... others may have a different perspective.

 

Did they tighten down the spark plug with the helicoil on it enough? I had something similar happen and just didn't have the plug with the helicoil on it tight enough so it started throwing the code again. Tightened it down more and no more code.

 

Thx. Unless they are forbidden to even slightly overtorque, wouldn’t this be an obvious thing for them to check? I guess I can doublecheck what the new fail really is ... I thought it was the helicoil has failed to hold / is loose and so no tightening of the plug would even matter.

 

That's what I thought too but you never know. They might be afraid to over tighten it and do more damage. If they used the factory torque spec with a heli coil it might not be in there tight enough. It's worth a shot before dropping money on a new engine.

 

If it were me, I would use some liquid metal or whatever to lock the helicoil into the head. I think they usually use red thread locker on helicoils. It its not holding I would try something else before giving up on repair of the cylinder and going for a replacement of the entire head. Whatever you use needs to be heat resistant and once she goes in she does not come back out, but that is what you want.

Best of luck, Clay

 

When mine (#2 & #3 cyl) loosened up the second time ('11 Sport AT), I used some blue threadlocker on all of them and tightened by hand. That was June 2015 at ~51,000 miles. Now have 80,000 miles and plugs have stayed tight. Continued to use all of the original coil packs. Maybe I'm just lucky but 30,000 miles / 4 years seems to indicate to me that it might work for others.

 

Here’s an update. I like the ideas to really make sure you cant salvage the coil seating / lock it in place, even after having done a helicoil or time-sert. This wasn’t an option for me logistically and I can’t do that repair myself. Honda service said there was just not enough metal left in the block to think the thing would hold again, and that’s a valid possibility too.

I was all set to get it towed to a cheaper non-dealer mechanic for the rebuilt engine but they (Honda service) wanted to work with me given the history, so knocked 25% off the all-in price and I think they did a good cannibalizing the new parts from original engine. Also got a rebuilt starter. The car had one month old tires, so I was kind of biased toward good money after good, of sorts. Running great now and if I were to sell it I’d probably get most to all my money back. As a trade-in it had negative value in its then state. The event forced my wife to buy a new CR-V, but sooner or later this Fit was going to get relegated to the beater role anyway.