Pulled out piston #4 today..."its Jaw dropping"(with pics)
06-03-2009, 10:23 PM
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Pulled out piston #4 today..."its Jaw dropping"(with pics)
Looks perfectly fine to me right?
NOT!!!
See Background info here https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/blown-piston-ring-suprise-56k%3Ddeath-173496/
Good thing we (my my buddy curt [Z_Speed] and I caught it soon. The Piece wasn't hanging out like it was showing, the ring was actually holding it in so it couldn't scratch the sleeve/walls. That piston, still held a 120 compression... So remember, if your numbers across the board aren't within 10%(i think that the variance allowed, if not someone correct me) its best to start investigating, because this could have been alooot worse.
[ The numbers went 180, 180, 180, 120]
guess nobody cares....i should change the title to "New girl to forums, just bought a cobalt LT" then this would be a 500 post thread...
NOT!!!
See Background info here https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/blown-piston-ring-suprise-56k%3Ddeath-173496/
Good thing we (my my buddy curt [Z_Speed] and I caught it soon. The Piece wasn't hanging out like it was showing, the ring was actually holding it in so it couldn't scratch the sleeve/walls. That piston, still held a 120 compression... So remember, if your numbers across the board aren't within 10%(i think that the variance allowed, if not someone correct me) its best to start investigating, because this could have been alooot worse.
[ The numbers went 180, 180, 180, 120]
guess nobody cares....i should change the title to "New girl to forums, just bought a cobalt LT" then this would be a 500 post thread...
Last edited by cobaltguy889; 06-04-2009 at 02:35 AM. Reason: Automerged Doublepost
06-03-2009, 10:33 PM
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not sure...i ran a 2.8" for a while, got a bad tune from a local tuner, blew the intake manifold gasket, went to 3" cuz i had blowby problems, tryed to retune, but we noticed a constant misfire in #4, ran a compression test and BAM! thats what i found.
The fact that the other three pistons were running 180 compression levels and #4 was 120 was enough for me to tear it apart lol...
The fact that the other three pistons were running 180 compression levels and #4 was 120 was enough for me to tear it apart lol...
06-03-2009, 10:36 PM
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not sure...i ran a 2.8" for a while, got a bad tune from a local tuner, blew the intake manifold gasket, went to 3" cuz i had blowby problems, tryed to retune, but we noticed a constant misfire in #4, ran a compression test and BAM! thats what i found.
The fact that the other three pistons were running 180 compression levels and #4 was 120 was enough for me to tear it apart lol...
The fact that the other three pistons were running 180 compression levels and #4 was 120 was enough for me to tear it apart lol...
06-03-2009, 10:39 PM
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thats my guess. I'm not worried about it. I have all the parts to do the rebuild in my garage. gonna do it next weekend.
well the g/f is bitching at me to go watch a movie, if anybody else has any questions, i'll be back on in a few hours to answer any
well the g/f is bitching at me to go watch a movie, if anybody else has any questions, i'll be back on in a few hours to answer any
06-04-2009, 02:27 AM
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damn! 0? Have you checked your oil at all lately? That might answer your question in itself.
cylinder walls are perfectly fine. I feel 0 imperfections. I'm actually really excited!
Originally Posted by ebristol
Very smart to take care of the problem before it got worse.
What does the cylinder wall look like?
What does the cylinder wall look like?
06-04-2009, 02:29 AM
#19
Mine did the same, it was 210-210-210-140 when I tested, and the side of the piston had the same symptom. I also had some of the material below the oil ring come off, it was down in the oil pan. Not much, but still something.
To be fair though, I drove the car for probably 4 months after I popped the piston, so I don't know if that happened at the same time or not.
To be fair though, I drove the car for probably 4 months after I popped the piston, so I don't know if that happened at the same time or not.
06-04-2009, 02:34 AM
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yea like whats funny is the day that i was driving to get some tuning, I walked a bolted early 90s 5.0 mustang that was talking **** at the stoplight. then we ran a compression test after we found that we were getting misfire. First thing i thought was wtf, i put like a bus length on a mustang this morning. and even after the compression test the car still moved pretty good.
06-04-2009, 08:04 AM
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yep me neither lol...and i'm being extra cautious and getting my rods cryo treated next week. i know it doesn't make a HUGE difference, but any help is something.
As crazy hard as people think it is to do this, it really isn't that hard on these cars.
As crazy hard as people think it is to do this, it really isn't that hard on these cars.
Last edited by cobaltguy889; 06-04-2009 at 08:04 AM. Reason: Automerged Doublepost
