Damage after h&c install.
#1
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Damage after h&c install.
This happened to my friends 03 Lumina. After installing the heads and cam it was used for about a month and then he saw oil in the coolant. After removing the heads, both pistons 5 and 7 were badly damaged and the head chambers as well.
I suspect a lean condition in both cylinders caused by dirty injectors since it had an occasional miss, but wanted to have more opinions.
I suspect a lean condition in both cylinders caused by dirty injectors since it had an occasional miss, but wanted to have more opinions.
#2
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First of all those plugs are junk. I wouldn't put those in any car. I'm sure the coolant entered the oil through the crack ring land. And, the coolant entered through the damage on the head. I would say the injectors had to go to a really lean condition to cause that. It should have missed really bad with it running that lean. By the way cylinder 3 looked it was running lean too. Is it a stock cam or aftermarket cam?
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Cracked or broken piston tops are the usual failure mode for detonation in GM engines. The banged up heads and spark plugs were likely a product of the broken pieces of metal flying around in the cylinder. So the question is: what caused the detonation? Certainly a lean condition under power could. But also timing errors caused possibly by a faulty sensor. I had a case of detonation and miss once when water leaked into a damaged O2 sensor cable shorting things out just enough to throw the AFR way off. Have you scanned for any current or pending DTC's? That might provide a clue. Also just wondering: he wasn't using any kind of FI or nitrous was he?
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#8
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We've scanned it and it was giving timing retard of 2-5° at part throtle when the converter locked up. Otherwise on WOT I've not seen any retard. It did occatioally idled very rough and stalled, which shouldn't be he case with a mild cam. The block and liner are cracked on that #7.
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Originally Posted by jaybob
03 Lumina?
#12
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The car wasnt on the bottle? Cracked ringlands definately make me think lean with severe detonation. It would have to be pretty damn bad to do this N/A.
Also, When did the NGK iridium plugs become junk??? I perfer the copper ones for price and short replacement, but i didnt think the IX were junk...
Also, When did the NGK iridium plugs become junk??? I perfer the copper ones for price and short replacement, but i didnt think the IX were junk...
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Might want to check the wiring and connector to the injector, and maybe replace the injector as well. I had a similar situation of randomly occurring knock and misfire on my '03 truck, and when I was disassembling the engine the injector connector fell off in my hand. Fortunately I was lucky and no damage occurred.
#15
Here's video for the car run with the problem & before we open the heads
http://video.ls1tech.com/video/f8f7a...ae010f027b.htm