So, is this rod knock? Audio clip included
#21
no worries man, you can sell the heads off that motor for what you paid for it. dont feel like you've screwed up. at this point, you can either pull this motor and rebuild it or give the 3.4 swap another go. however, since you've already been through the top end, i would suggest just getting the short block built by a machine shop locally, which should be well under a grand (significantly cheaper than that if you build it yourself, not sure what your engine abilities are). so its not really a huge setback imo.
#22
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I was about to say, for the $150 you've got in that motor, you would come out ahead even if you just scrapped the thing. Far as I can figure, you're still in the black
#23
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Okay, here's an update, I'll try to be as specific as possible.
Thanks to the 4" lift I just put on, I was able to swing the steering linkage out of the way, and drop the oil pan. There were no noticeable chunks of metal in the pan. I pulled 2 rod caps so far: #1 and I believe #4 (the suspect cylinder). The bearings were slightly scratched in the middle, and a little discolored (whitish). A small hint of oil starvation (black streak) was on the back of one of the bearings. The crank looks completely unharmed, no scoring what so ever. I checked the clearances with plastiguage and it falls within spec for standard size bearings.
So, I'll continue to check the rest of the rod bearings, and will be replacing the entire set (so long as they continue to stay in spec). I'm not sure if I can check/replace the main bearings this way, anyone have a clue?
Also, I'm going to doubt that ignition timing would cause that much noise? I just remembered that I timed the distributor per the manual (TDC, etc.), but I didn't adjust it after I started it.
Thanks to the 4" lift I just put on, I was able to swing the steering linkage out of the way, and drop the oil pan. There were no noticeable chunks of metal in the pan. I pulled 2 rod caps so far: #1 and I believe #4 (the suspect cylinder). The bearings were slightly scratched in the middle, and a little discolored (whitish). A small hint of oil starvation (black streak) was on the back of one of the bearings. The crank looks completely unharmed, no scoring what so ever. I checked the clearances with plastiguage and it falls within spec for standard size bearings.
So, I'll continue to check the rest of the rod bearings, and will be replacing the entire set (so long as they continue to stay in spec). I'm not sure if I can check/replace the main bearings this way, anyone have a clue?
Also, I'm going to doubt that ignition timing would cause that much noise? I just remembered that I timed the distributor per the manual (TDC, etc.), but I didn't adjust it after I started it.
Last edited by Cyberman; 07-02-2008 at 05:04 PM.
#24
Speaking from experience, the 3.0 has very little clearance between top of pistons and cylinder head. When a rod bearing spins and generates excess clearance, the piston starts slapping the head which will eventually crack the head from the pounding. Crack usually occurs internally.
Since the bottom end is an unknown, it is highly suspect. You can pull the lower mains by removing the cradle that spans many main bearings. It is a bitch to install on an engine stand.
I vote to pull the engine and take it to a shop. Let them clean all the parts and see if they can hone the block for new rings and turn the crank. There are 3 left and 3 right pistons. Do not mix them up. Let them assemble the block and be responsible for the results.
When you pull the heads, look for the piston/head slap. It will be on the head and top edge of the piston(s).
My $0.02
Since the bottom end is an unknown, it is highly suspect. You can pull the lower mains by removing the cradle that spans many main bearings. It is a bitch to install on an engine stand.
I vote to pull the engine and take it to a shop. Let them clean all the parts and see if they can hone the block for new rings and turn the crank. There are 3 left and 3 right pistons. Do not mix them up. Let them assemble the block and be responsible for the results.
When you pull the heads, look for the piston/head slap. It will be on the head and top edge of the piston(s).
My $0.02
Last edited by SEAIRESCUE; 07-02-2008 at 05:50 PM.
#25
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The low compression was not #6, it was #4. The engine did not have a blown HG. The noise does sound terminal, and would be if I actually tried to drive it that way. I'll figure it out. It's not a sad story, it's my own fault for not checking out the bottom end first. It'll be okay, it's not my DD. It was given to me with 2 blown cylinders with a hole inside the block. It hasn't run up until now, so this is an improvement.
But really it doesn't matter. If it's #4, a spun rod bearing with enough slop will decrease the piston height at tdc considerably resulting in lower compression readings.
Well I guess all that's left is to "git r dun"
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