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Old 07-22-2016, 09:13 AM   #1
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Default Bent spark plug + knock.

Shitty night.
Car was running fine.
Installed a new boost controller and went from 7.2 to 10.8 psi over a couple clicks - wasn't expecting that. Recently installed 610cc and have not really fine tuned them, so car was running RICH.
Car started struggling once i hit 10 psi.

Within 2km she was running on 3 cylinders /misfiring.

I limped home and pulled plugs.

Obvious knock.



Next baffles me. Same plug is cylinder 1. It's squished, resulting in the misfires.



Will jump on the laptop and post log / car details.
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Old 07-22-2016, 09:16 AM   #2
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Looks like you have FOD.
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Old 07-22-2016, 09:26 AM   #3
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So 1.8 2000.
610cc
26" ebay-cooler
TD04
COPS
DIY manifold / downpipe / 3" exhaust + catback to 2.5 stock muffler behind diff.

Log and ms attached.
Note that the fuel is all fucked as it started misfiring during veal and it was just adding fuel across the board. Also high kpa are rich as i have not reached / tuned them yet.
Attached Files
File Type: msq 2016-07-22_23.18.30fk.msq (244.2 KB, 26 views)
File Type: msl 2016-07-22_18_modified.msl (2.91 MB, 29 views)
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Old 07-22-2016, 09:26 AM   #4
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Quote:
Originally Posted by rleete View Post
Looks like you have FOD.
Foreign object.
intriguing.

Anywho it's midnight - i need sleep.
Tomorrow hopefully i can tackle this with more intelligence.
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Old 07-22-2016, 06:20 PM   #5
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Cylinder one is showing 40 compression cold.
Other 3 are 155 solid.

Looks like I get to explore the internals of my first motor. Hopefully a valve... Maybe a ring...

Any ideas?
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Old 07-22-2016, 06:31 PM   #6
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Det could easily fold an electrode over like that.

Or the ringland did it, cause that's like no compression.

Pre-ignition is a thing, too. Much worse than det. How rich is RICH?
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Old 07-22-2016, 07:01 PM   #7
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Only went to 10afr at lowest during boost I think. I heard a second of loud bouncing metal while limping home. Anywho looking in cam cover everything looks new.

Now I need to work out how to pull the head without messing up timing.
I have access to a crane and stand so that's a maybe.
Looks like its time to search and brush up on the next steps.
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Old 07-22-2016, 07:11 PM   #8
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You need a crane and stand to pull the head? What does pulling the head have to do with timing? Did you loose the last timing light ever made or something?

Buy one of the cheap USB borescopes, or just use a flashlight. I bet you see something pretty brutal...



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Old 07-22-2016, 08:02 PM   #9
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Pulling the engine is due to also needing to do a clutch.
But I'll just pull the head now. Again excuse my terminology. More worried about positioning of cam shafts etc - not timing.

Its my first engine opening, cut us some slack!
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Old 07-22-2016, 08:05 PM   #10
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Very few small sparkles in oil drain. Most are non magnetic. Considering I recently drilled the pan...

Last edited by adryargument; 07-22-2016 at 08:48 PM.
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Old 07-22-2016, 08:06 PM   #11
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If you're thinking about FOD, start by pulling the intake tube and checking to see if you still have both of your throttle body screws and all of the shaft.

--Ian
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Old 07-23-2016, 12:07 AM   #12
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Checked the Tb already. All In one piece. Bloody house inspection. Waiting for potential buyers to leave grrrr.
Have the belts and timing belt plates off. Need to Mark the cams and then I should be ready to pull.
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Old 07-23-2016, 04:03 AM   #13
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Time to have a big long think about the future of this motor..
Possibly time to upgrade to a vvt.

Learnt alot today.

1. One of rear studs was hand tight /loose. Very minor headgasket leak. That cylinder has perfect compression...

2. Cylinder one is dead. The cylinder walls look perfect.... But FOD.

3. Turbo is unharmed. No sign of object...

So now I need help. I'm assuming the head is unrecoverable with the damage? No chance of those seats resealing / loss of meat changing compression?
Piston is fine, bit of a spit shine and shes good to go....











Last edited by adryargument; 07-23-2016 at 04:22 AM.
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Old 07-23-2016, 06:45 AM   #14
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Default Bent spark plug + knock.

Is the crank fine? Bore out the cylinders, fill with forged goodies, and get a vvt head. Im sure the senior mt.net members will chime in with the right advice. Good luck

Edit: how good did u check the turbine wheel? If the FO did that to piston/head i cant imagine the turbine is fine. Did you look all the way in and inspect the inducer?
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Old 07-23-2016, 07:22 AM   #15
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Just looked under its skirt. I'll crack it in half tomorrow and do a thorough look.

I have looked at alot of options today for building a new motor etc. Its not really fitting my current budget. I have 15x9's + tyres arriving in 2 weeks outstanding.

The piston is sure beat up. But she slides well with no marks on the cylinder walls. I'll have a grind at the valves tomorrow and see if I can get them seating better - since that's where I'm losing compression. Then I'll put her back together and have some fun and improve my tuning while I work on a vvt replacement engine.

Happy that there's no real sign of det. At least it's not caused through rubbish tuning.
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Old 07-23-2016, 11:48 AM   #16
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I bet the culprit is caught in the catalytic converter. Empty it out, let's see what it was.
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Old 07-23-2016, 12:15 PM   #17
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If it did that to the piston and went through the turbo without damage, you got really really lucky.

If it's just a stock head then I'd just replace it. If it's got expensive porting/etc done to it then it might be worth trying to recover it.

Hammering something into the head hasn't done the rod or the rod bearing in #1 any good. At a minimum I'd pull the rod out to check it for straightness and replace the bearing.

--Ian
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Old 07-23-2016, 12:45 PM   #18
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replace that piston man. you have it open, dont halfass on something like that. Even if it is only stock replacement piston, it needs to be changed.
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Old 07-23-2016, 02:22 PM   #19
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Main issue is Australia.
I have not seen a replacement head by itself for sale yet, unless i pull one from a wreckers. Considering last time they wanted $65 for a single COP....
Once i remove the crank, open her up and replace the piston / rod, seals...

Its probably just cheaper to drop in a new engine. Looking at a VVT engine now that's available. Will get compression numbers on Monday.
May as well put this back together and get her running however she sees fit until that happens. Even if its limp mode.

And its a bad time to have her open. If the house sells then i need her running in 4 weeks anyhow.
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Old 07-23-2016, 08:09 PM   #20
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Looks like I missed a piece of weld splatter in my intake pipe. Going to remove them and rebuild.

Found the little ****** lodged in the intake valve. Probably causing the loss of compression. Lucky she wasn't in the turbo.
Going to lap the seats. Grind away the hammered flaky bits on the head and piston and call it a job well done.

Being a sphere probably allowed it to miss the cylinder walls.




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