The Project Pad

Could also just be a dead spark plug, specially if it's resistor plugs. Coil seems to spark pretty strong from sound.

Worst plug EVER!!!!!


Confirmation...

All that work gone in 3 day use of these plugs...

In retrospect, it was built by myself, to my own liking, have a dyno chart, got a time slip, dozens of videos, a few cool pics and a Launch meme/gif out of it... it was fun, just was way to short lived... I'll be signing off for now and swapping plates back to the Jetta until I figure out the direction needed to go...

sucks man, but obviously it just makes sense to tear her down, fix the dead hole and continue on (maybe get a dyno tune). The cost to get that hole fixed is minimal compared to everything else you have done. Even if you need to get another block and transfer parts onto, its really not a big deal. Bummer though.

also, i dont think i would assume the plug caused this, I would be more inclined to think cylinder temps and/or timing melted this plug. I've had plugs do this racing dirt bikes on the ice in the winter when my jetting was too lean and ruin motors. I blamed the plugs at first, but then realized my tuning was too lean for the cold temps.

When I was riding with Matt along next to your car, your header was glowing very red even just crusing, so maybe your egt's were crazy high.

Nope... super mild timing and boost was at a conservative 24psi... I was running weak sauce pump... DTC's handled that since the time I've assembled this motor and previous builds.

these were just pulled out Sunday, 10k on them...

i am still doubtful that the plugs just melt by themselves under ideal engine conditions.

dana wrote:i am still doubtful that the plugs just melt by themselves under ideal engine conditions.

Could've just cracked... was instructed to gap down to an extreme .019 ...

so was this just one hole that melted the plug, or did multiples look like that?
crazy that the 3 prong plugs look so good!

dana wrote:so was this just one hole that melted the plug, or did multiples look like that?
crazy that the 3 prong plugs look so good!

I just didn't have the 5th in the picture... all 5 looked good, were just worn as it started to misfire at 6800rpm... I replaced them with these NGK R5671A-9 as part of being a responsible owner that maintains his vehicle... Had soo much better luck with BKR7E as well...

All I can say is wow, no motivating words here we all now how you always bounce back. Glad you have a backup car man.

much love - mage

Something else is going on. The group of 4 Bosch plugs look like they have been running lean. I love the Ngk plugs you describe above for pump gas at least. I was quick to blame Bosch in one of my other threads though and they were definitely not the root of the problem. Either way it sucks. I have learned to tune by plug color regardless of what any gauge is telling me. If they are not light brown, the tune is off.

What is the most recent log you have OB?

Log from previous page indicates 308kpa at 5244rpms and 19 degrees timing...isn't that to much timing on stock comp motor?...egt seems low too at 706c.

sorry to see man, but that cylinder definitely experienced detonation

it seemed you were switching between pump/e85 often, may have been a blend one way or the other that was not sufficient for the tune

Dude that sucks! :(

EDIGREG wrote:sorry to see man, but that cylinder definitely experienced detonation

it seemed you were switching between pump/e85 often, may have been a blend one way or the other that was not sufficient for the tune

I never run my E85 tune on pump... If anything its inverse like at Carlisle... For what it's worth, running it that way should further prevent DET... My pump tune hasn't changed since Marc and I road tuned it for break in purposes, which he used knock-phones with. If the blend wasn't enough for the tune, what's that say about my other other 4 plugs? Same batch of fuel...



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Well, you didn't post the other 4 plugs so I can't comment on what they look like.

For what it's worth, running it that way should further prevent DET

That's not correct, it goes both ways:
Too little ethanol on E85 tune = too much timing
Too much ethanol on pump gas tune = lean

Or, your fuel pressure could have been dropping.

Either way, there was det on #5.

Also, #4 and #5 are known to be the leanest cylinders with the stock intake manifold.

Is your intake gutted Ob?

audifreakjim wrote:Something else is going on. The group of 4 Bosch plugs look like they have been running lean. I love the Ngk plugs you describe above for pump gas at least. I was quick to blame Bosch in one of my other threads though and they were definitely not the root of the problem. Either way it sucks. I have learned to tune by plug color regardless of what any gauge is telling me. If they are not light brown, the tune is off.

this is what im geting at too, i think those bosch plugs might be tougher, but to have your NGK plugs melt like that sounds more like a tuning issue than plug failure. I have used NGK plugs in a lot of engines, and never had that happen unless things got too lean (hot).

I hope you get it back up to snuff, I loved that car. Looks soo good and goes like snot.

I agree, this seems like too lean and then det.

The four plugs pulled on Sunday are not the same as the failed one. Ob, are you able to post up all five from the Sunday pull as well as all 5 of the carnage plugs please.

Edit: that was dad posting from my account

EDIGREG wrote:Well, you didn't post the other 4 plugs so I can't comment on what they look like.

For what it's worth, running it that way should further prevent DET

That's not correct, it goes both ways:
Too little ethanol on E85 tune = too much timing
Too much ethanol on pump gas tune = lean

Or, your fuel pressure could have been dropping.

Either way, there was det on #5.

Also, #4 and #5 are known to be the leanest cylinders with the stock intake manifold.

I hear you, but the DTC's I posted have been there for MUCH longer and we're just swapped out during this same exact tank of gas...

My logs have never reflected any loss of pressure at even 30+ psi on e85... If anything its been rich at that level

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chaloux wrote:The four plugs pulled on Sunday are not the same as the failed one. Ob, are you able to post up all five from the Sunday pull as well as all 5 of the carnage plugs please.

I only posted the DTC as they were in way longer and if anything they've been thru all my tuning revisions along with fuel mixtures ever... The fifth DTC is in my glove box... I'll group them all together tomorrow an take pics...

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.020" is the gap to run, not that .019" caused your problems here. as I mentioned via text, certainly detonation and possible high egts to cause the plug to look like that.

You were logging fuel pressure? I don't see it in your log

It would be helpful to see the 5th DTC that is missing from the photo (why photograph only 4 plugs?) and detailed photos of all, as well as detailed photos of all 5 of the NGK plugs.

There are a lot of things that could have gone wrong man, you need to provide as much info to the forum as you can if you want help diagnosing. Wb02 could have been bad or not properly calibrated? vacuum line to the FPR could have had a leak? #5 injector failure? Etc