Sheila's car has been in and out of the shop for three weeks now. Here's the history:

• Crank car for commute home from work, has severe missfire. CEL codes 300 301 302 303 304
• Dealer swaps in known good coil packs
• Dealer swaps cyl1 and cly2 fuel injector
• Dealer drains gas tank and tries new gas
• Dealer replaces spark plugs
• Dealer checks valve adjustment (last done 6 months ago) find them 2 thousands tighter than spec
• Dealer decides OXY sensor is "slow" even though no code is thrown
• Replace OXY sensor, miss is gone. happy happy joy joy
• Car starts missing again after first cooldown cycle, not as bad but still throwing codes
• I bring my car in and we swap fuel injectors and map sensor. Car runs great until first cooldown cycle, miss returns
• Car is running rich (seen in short term fuel trim) Honda tech says "bent valves"
• Pulled head (pictures below) poured water into head, 15 of 16 valves show leakage
• Any other ideas on this?

 

Ok, hopefully a CO will move it.

I took this to be a more _technical_ issue.

MyBad.

 

I think you are right and I am wrong.

 

No worries.

 

The original idea of the Technical subforum was to essentially move the original UTH forum to a subforum and allow UTH to be more open. Mostly Technical should be about DIY writeups and discussions, with UTH being more general discussions of mechanical issues on the S2000.

That's how I remember it, anyway.

Given this definition, this is a UTH issue rather than a Technical issue.

 

Either way is fine with me. I assume the moderator will move it wherever it belongs.

Mostly, I'm interested to see if anyone has comments on the thread rather than where it is posted.

 

Are the valve stems actually bent? That's easy enough to check for, just rotate them and see if they wobble.

Failure to seal could be a lot of things.

 

If they're bent, it's too small a bend to detect by rolling, or so the mechanic says.

Stupid me didn't just take one and roll it to verify it. I'll do that tomorrow morning.

 

Sorry to double post...

What type of "other things?" That's exactly the type of information I'm looking for.

 

The F20 head is known for having crappy retainers. Bad valve adj. + miss shift= bend valves. If the car is under warranty they should replace the head, just don't mention the miss shifts. just my 2 cents