BenKey Posted December 14, 2005 Report Share Posted December 14, 2005 I see, the boost spikes dont worry my to much, and i did do the compression test with the engine cold, i didnt want to run it been as it was missfiring. in that case i will put the spark plugs back in and warm it up, maybe a new spark plug will take care of the miss fire, been as there was no gap in the one i pulled out of cylinder number 7. <{POST_SNAPBACK}> No gap could be caused by pistons coming apart. I know thats not a good sign but its definately a possibility that the piston has fractured and part of it closed the gap. <{POST_SNAPBACK}> Sounded that way to me too, but doesn't seem it would run at all if that kind of damage happened. could be wrong though. what else could have bent the electrode? does the electrode look like anything impacted it? Link to comment Share on other sites More sharing options...
06VHO Posted December 14, 2005 Report Share Posted December 14, 2005 Sounded that way to me too, but doesn't seem it would run at all if that kind of damage happened. could be wrong though. what else could have bent the electrode? does the electrode look like anything impacted it? <{POST_SNAPBACK}> if it did not come in contact with anything, detonation can cause a ground electrode to move. Link to comment Share on other sites More sharing options...
chpspecial Posted December 15, 2005 Author Report Share Posted December 15, 2005 I'm going to have to wait until sat, to further check what the problems is. When i get home its already dark and it gets cold fast. The heads will be coming off to check the pistons, hopefully number 7 wont be comming apart as you guys have mentions, and if that was the case wouldnt it reflect on the compression. Thanks for the imput everyone Link to comment Share on other sites More sharing options...
06VHO Posted December 15, 2005 Report Share Posted December 15, 2005 I'm going to have to wait until sat, to further check what the problems is. When i get home its already dark and it gets cold fast. The heads will be coming off to check the pistons, hopefully number 7 wont be comming apart as you guys have mentions, and if that was the case wouldnt it reflect on the compression. Thanks for the imput everyone <{POST_SNAPBACK}> if your compression test was accurate, you have major issues. with a leakdown test it will let you know where your problem is (eg. piston/rings, intake valve, ehaust valve, head gasket, etc.), but you may already know this. good luck. Link to comment Share on other sites More sharing options...
2006LS2TB Posted December 18, 2005 Report Share Posted December 18, 2005 Any news yet??? Link to comment Share on other sites More sharing options...
chpspecial Posted December 18, 2005 Author Report Share Posted December 18, 2005 The rockers look ok, pushrods are still good, i still havent pulled the heads so i dont know the status of the valves and springs but from looking at them they seem fine. Hopefully today, sunday, the heads will be off. the way things are going i think i might find a hole where a piston should be. Link to comment Share on other sites More sharing options...
chpspecial Posted December 19, 2005 Author Report Share Posted December 19, 2005 Update: Heads are off as well as the lifters and nothing is visibly wrong, lifters look ok, and heads look fine, pistons also look in good shape. all of the gaskets looked in good shape also. Wich sucks because i dont know what is wrong and the truck is all apart, When i put her back together i might do teh Z06 valve train. or is there something better for the price? Link to comment Share on other sites More sharing options...
06VHO Posted December 19, 2005 Report Share Posted December 19, 2005 How did it run with 8-good spark plugs? What were your compression readings warm? or even better What were your leak-down results? (I hate to beat a dead horse here) If you performed a leak down-test and: everthing checked out good your done. it showed a leaking valve you'd pull that head and inspect that valve. it showed a leaking piston/ring you'd pull the engine apart and inspect that piston/ring. it showed a leak to the cooling system you'd check for a bad head gasket, cracked head, cracked block, etc... If you did not troubleshoot properly: where is the problem? is there a problem? Link to comment Share on other sites More sharing options...
chpspecial Posted December 19, 2005 Author Report Share Posted December 19, 2005 I didnt do a leakdown test as per the advice of another tech that works with my brother, now i'm begining to think that i should of had done it. it could have saved me lots of time and maybe it would of had not needed for me to do anything. anyhow the teardown is done, oh well. My brother has the heads at his shop and he will check the valve seats and check them out, hopefully the truck will be back in action by the end of the week. Link to comment Share on other sites More sharing options...
06VHO Posted December 19, 2005 Report Share Posted December 19, 2005 did you ever fire it up with 8-good spark plugs? if you did and it ran good you should feel confident putting it back together. good luck. Link to comment Share on other sites More sharing options...
BenKey Posted December 19, 2005 Report Share Posted December 19, 2005 Could still be a damaged piston. The ring-lands can file up also. That you may not be able to see. Is there any scoring on the cylinder walls? I think the excessive misfiring was due to the one plug the way it was. The problem is not knowing how it got that way. Would too much pre-detonation cause that? Link to comment Share on other sites More sharing options...
06VHO Posted December 20, 2005 Report Share Posted December 20, 2005 Could still be a damaged piston. The ring-lands can file up also. That you may not be able to see. Is there any scoring on the cylinder walls? I think the excessive misfiring was due to the one plug the way it was. The problem is not knowing how it got that way. Would too much pre-detonation cause that? <{POST_SNAPBACK}> yes, there can be a damaged piston (collapsed ring land), a cracked ring, a cracked cylinder wall, a cracked head, etc. and can be hard to find. if it ran good with 8-good spark plug then it is probably fine though. detonation does cause spark plug ground electrodes to move around, become shorter, or come up missing completely. possible causes are lean air/fuel mixture, too much ignition advance, not enough octane, spark plug heat range too hot, wrong style spark plug (projected tip spark plugs should not be used with lots of boost and a colder plug is a must), simply not enough gas in the tank, the harder you launch the more important it is to keep plenty of gas in the tank (because it all wants to go to the back of the tank and the fuel pump sucks air). Link to comment Share on other sites More sharing options...
chpspecial Posted December 20, 2005 Author Report Share Posted December 20, 2005 cylinder walls look just fine, no damage to them, i did have about a 1/4 tank of gas when i was running it. Link to comment Share on other sites More sharing options...
06VHO Posted December 22, 2005 Report Share Posted December 22, 2005 good time for some porting or cam change Link to comment Share on other sites More sharing options...
chpspecial Posted December 22, 2005 Author Report Share Posted December 22, 2005 found a problems, exhaust valve on cylinder #7 is bent. maybe others. This actually makes me feel better now. Link to comment Share on other sites More sharing options...
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