Damage after h&c install.
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From: Bahrain
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.
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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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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From: The beautiful Kingdom of Bahrain
Originally Posted by jaybob
03 Lumina? 
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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From: Western WA
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.
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Here's video for the car run with the problem & before we open the heads
http://video.ls1tech.com/video/f8f7a...ae010f027b.htm