INTERNAL ENGINE MODIFICATIONS Valvetrain |Heads | Strokers | Design | Assembly

HELP PLEASE!! Engine Vibration after rebuild LQ4

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Old Aug 13, 2010 | 09:37 AM
  #11  
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Originally Posted by Remember_54
will check them again... they all plugged, but maybe we did not plug right on to same place, we run OBDII test, everything fine that why I was sure that everything should be plugged right.. anyway will check again if we mess the places, but think that everything is correct..

what you think on balance the crankshaft.. ?
and how you think maybe we chose the wrong position from timing chain, it has different positions our one for a moment is R2 (Manley timing set LS 3-bolt with captive Torrington thrust bearing and 9 keyway sprocket)
it has A2, A4, A6, A8 , 0 , R2, R4, R6, R8

can this course vibration ?
Do a compression test! Idk what it's suppose to be but if it's to low the timing could be off!
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Old Aug 13, 2010 | 09:46 AM
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Originally Posted by mhotrodscooter
Do a compression test! Idk what it's suppose to be but if it's to low the timing could be off!
will check that today..

actually i did not do it before because factory gauge which showing oil pressure, showing maximum, but will do the compression test today..

our compression should be 9:1

very bad to build and dress up engine and now I think I will go all the way back
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Old Aug 13, 2010 | 10:19 AM
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I'm thinking it should be around 130psi but I could wrong! Maybe somebody else knows
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Old Aug 13, 2010 | 01:11 PM
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I had an issue once with the Coil packs being plugged in wrong too. I got a thermal laser gun and read the temps off the primaries and saw which cylinders weren't firing.
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Old Aug 13, 2010 | 11:03 PM
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Originally Posted by Spoolin
I had an issue once with the Coil packs being plugged in wrong too. I got a thermal laser gun and read the temps off the primaries and saw which cylinders weren't firing.
I will not able find thermal laser gun here, maybe it some kind different way to check it?
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Old Aug 13, 2010 | 11:07 PM
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Originally Posted by Remember_54
I will not able find thermal laser gun here, maybe it some kind different way to check it?
by another word coil packs can course this vibration, and when they not right are the rmp stays as normal or start going up and down
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Old Aug 13, 2010 | 11:07 PM
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Use a spary bottle with water! Spary on each exhaust port! Should burn off fast if it's firing on the cylinder!
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Old Aug 14, 2010 | 01:07 AM
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Originally Posted by Remember_54
and how you think maybe we chose the wrong position from timing chain, it has different positions our one for a moment is R2 (Manley timing set LS 3-bolt with captive Torrington thrust bearing and 9 keyway sprocket)
it has A2, A4, A6, A8 , 0 , R2, R4, R6, R8

can this course vibration ?
Im guessing the A means advanced and R means retard, in which case, I would have installed it straight up (0), but having it at R2 should not cause this much of an issue.

The thing that really struck me is they ground the crankshaft and no mention of balancing it. The crank is the hardest thing to test though, so start with easier stuff like the coils...

If the water thing doesnt work, you can unplug them one by one (but reinstall before you move on to the next one) and listen for a change in the engine sound. If the one you pull doesnt change the engine RPM or stability, then you know you have a bad one. Also check the spark plugs. If one or more of them is fouled, that cylinder is very rich and could be because of no spark.
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Old Aug 14, 2010 | 02:22 AM
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After ALL test done we found out that we do not have compression on right Head, driver side compression is good, but other side compression is zero..

So what that mean, is that mean I need to change Engine Cylinder Head Block because it seems to have damaged?

visually they all been ok.. before installation I even installs new valve ans spring plus rockers
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Old Aug 14, 2010 | 08:10 AM
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which cylinder or the entire bank?
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