Help! Spark plug #1 fouling
#16
Compression test in #1 is 150 but it's false. You have excess oil in the cylinder so it's wet and boosting the numbers. I agree with joeycoates. Most likely a cracked piston or broken ring land. Leakdown test would tell you more but really I would just take the schrader valve out of the compression test hose and put compressed air in the cylinder. You will probably hear it free flowwing into the crankcase. Do it to another cylinder for comparison and you will see the difference.
#17
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So let me ask is my situation different? My #4 has oil on the threads but since I have cleaned it out down there everything is well. I have no loss in power, the actual electrode on the plug is fine and the white part is just like the others. When I saw this thread I went out and pulled the plugs and compared they all seem the same and looked down each cylinder with a flash light and they all look the same. All this talk of short blocks and cracked pistons makes me sick to my stomach.. LOL
I just have a feeling that some oil was splashed down there when the cam install was done because there was actually oil where the boot goes onto the plug itself above the area that is used to crank them in with a ratchet..
I just have a feeling that some oil was splashed down there when the cam install was done because there was actually oil where the boot goes onto the plug itself above the area that is used to crank them in with a ratchet..
Last edited by ThEHiTMaN; Jul 3, 2005 at 09:04 PM.
#18
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Originally Posted by timzcat
Compression test in #1 is 150 but it's false. You have excess oil in the cylinder so it's wet and boosting the numbers. I agree with joeycoates. Most likely a cracked piston or broken ring land. Leakdown test would tell you more but really I would just take the schrader valve out of the compression test hose and put compressed air in the cylinder. You will probably hear it free flowwing into the crankcase. Do it to another cylinder for comparison and you will see the difference.
Moreover, I heard no audible pinging, and I've heard a ton of knock in 4G63s before.
About pulling the oil cap, the rpm doesn't change at all. No oil blows up and out either. Air does come out of the cap, but all three Evos at my house tonight did the exact same thing, because they're supposed to (PCV valve).
Andrew from Dyno4mance was out here tonight, and he isn't really concerned that its a problem. There's no visible oil coming from the tailpipe except when we put a tiny capfull in #1 and then you could see it coming out bigtime.
The way #1 is coated is not different than a lot of other pistons I've seen, but my other three are pretty clean. Ironically, #3 is the cleanest of the bunch.
It is still making great power on the dyno and is running well with the new plug.
At this point, I'm going to take Andrew and Eric's advice and continue driving it and enjoying it. I will keep a very watchful eye on that plug and cylinder, though, and see if the oil continues to manifest.
#23
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Originally Posted by ShapeGSX
If you have oil on the threads, perhaps your gasket on the #1 spark plug well is shot?
Have you ever poured oil down that spark plug hole?
Have you ever poured oil down that spark plug hole?
You might be onto something though, Josh. That makes a lot more sense than anything else, but the bottom of the plug that physically goes into the combustion chamber is much darker than the rest of the threads. The fact they are even wet at all is suspect though.
I really appreciate your insight here. Thanks a lot, man!
#26
Unfortunately, that sounds about right. Something closed the gap on that plug and it most likely was the piston or debris from the piston. If it was the rod then you would be hearing it. It sounds like a broken ring land.
#28
Which problem?
I spoke to Evo2quik4u for about 1/2 hour about his car. Unfortunately it sounds like he has a broken ring land. He will know more tomorrow.
Noize,
What part of the plug is wet, exactly? The threads only, the tip and ground porcelein?
I spoke to Evo2quik4u for about 1/2 hour about his car. Unfortunately it sounds like he has a broken ring land. He will know more tomorrow.
Noize,
What part of the plug is wet, exactly? The threads only, the tip and ground porcelein?
#29
Oh I just saw your post about your friend having the tools.
You can skip everything and go right to a leakdown test. This is the only true test of the ring seal in the cylinder.
You can skip everything and go right to a leakdown test. This is the only true test of the ring seal in the cylinder.
#30
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Originally Posted by timzcat
Noize,
What part of the plug is wet, exactly? The threads only, the tip and ground porcelein?
What part of the plug is wet, exactly? The threads only, the tip and ground porcelein?
Leakdown test coming this weekend. Will update. Thanks everyone for input.