2G 6 bolt Knock like a thrown rod. nothing looks wrong.

[jonseclipsegs]

My buddy and I recently took off the head of his car because there was a loud knock as though he had thrown a rod. He has a 95 gsx but it has a 6 bolt swap done to it. We got the head off and look at the valves. They seem to look fine other then being black and white from running rich and lean.

Then we looked in the cylinders and noticed there were 4 notches in the corners on the top of all the pistons as though they were hitting the valves. The valves looked fine but then I was thinking maybe the guy he bought the car from had put in pistons (it doesn affect the piston at all).

Like I said, everything seems to look fine yet there was major knocking sounds coming from the car when he tried to start it. Then it would die after like 2 seconds, just like a thrown rod would sound like. Nothing looks wrong though.

I have a bunch of pictures of the block and the head showing the cylinders and valves. I don't know it they will help but i have no idea at this point considering I didn't see anything, especialy after what I heard.

These are of the head and valves...
http://i154.photobucket.com/albums/s251/tmoney51486/Topofthehead.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/UndertheHeadwithValves.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Valves1.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Valve2.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Valve3.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Valve4.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/UpcloseValve1.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Upclosevalve4.jpg

These are of the block, cylinders, and pistons...
http://i154.photobucket.com/albums/s251/tmoney51486/BlockCylinders.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/BlockTop.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Piston1.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Piston2.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Piston3.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/Piston4.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/CloseSidePiston.jpg
http://i154.photobucket.com/albums/s251/tmoney51486/CloseTopPiston.jpg

Help please...

 

[SBstar]

Some of those pictures are rather blurry but I'm going to guess your problems are on the bottom of the motor not the top/middle. My guess is that he spun a rod bearing. Turn the block over, pull the oil pan, and check. A good first sign is a discoloration on any of the rod caps. The last engine I pulled apart with a spun bearing didn't have any discoloration, but just wiggling the end of that rod cap showed which one was spun.

A good way to check those valves to make sure none are bent is to shine a light through the top of the head and turn the cams over, waiting for each valve to seal and seeing if any light is coming through.

 

[TSG59_Steve]

Some of those pictures are rather blurry but I'm going to guess your problems are on the bottom of the motor not the top/middle. My guess is that he spun a rod bearing. Turn the block over, pull the oil pan, and check. A good first sign is a discoloration on any of the rod caps. The last engine I pulled apart with a spun bearing didn't have any discoloration, but just wiggling the end of that rod cap showed which one was spun.

A good way to check those valves to make sure none are bent is to shine a light through the top of the head and turn the cams over, waiting for each valve to seal and seeing if any light is coming through.

That get's my vote too.

 

[tqmx1]

If it is somthing in the bottom cut open the oil filter and see if it made metal. It.s quick and a dead give away if somthing is coming apart.

 

[WOTDSM]

+3. You have pretty headstuds too...

 

[SBstar]

If it is somthing in the bottom cut open the oil filter and see if it made metal. It.s quick and a dead give away if somthing is coming apart.

Ahh yes another great idea.

 

[jonseclipsegs]

+3. You have pretty headstuds too...

Yhank You ....

As for the oil filter...I dropped the oil pan before I started and there were no metal shards anywhere in the oil.

 

[SBstar]

Are you sure you dropped the oil pan? I just got a pm from 2alpha on this site. He's new so he can't post in this section but he pointed out your problem. Look at this picture again.

http://i154.photobucket.com/albums/s...kCylinders.jpg

Notice the number 4 piston is at top dead center, now look at where the number 1 piston is at. Notice anything wrong. You definitely broke a rod!

Pull the oil pan off for sure this time and you'll see for sure, you snapped a rod buddy.

 

[HIGHPSI4]

Ding....Ding.....Ding.....we have a winner. That #1 rod is gone. I hope you are lucky and the broken rod did not damage the cyclinder wall. I have seen these bust through and dump coolent into the oil pan.

 

[TSG59_Steve]

Are you sure you dropped the oil pan? I just got a pm from 2alpha on this site. He's new so he can't post in this section but he pointed out your problem. Look at this picture again.
http://i154.photobucket.com/albums/s...kCylinders.jpg
Notice the number 4 piston is at top dead center, now look at where the number 1 piston is at. Notice anything wrong. You definately broke a rod! Pull the oil pan off for sure this time and you'll see for sure, you snapped a rod buddy.

Wow, didn't even look at the pictures. Just went by what he described. To your friend: Good call.

 

[1g_tsi_awd]

I was gonna ask if #1 looked off... Best of luck with the fix.

 

[Maglin]

. It took long enough for someone to see that. This is the first time I've seen this thread and #1 looked all kinds of wrong on the head. Then I saw #1 piston sitting at the bottom when #4 was wasn't. That rust on the #4 exhaust valve is bad. Your #1 intake valves look like utter crap. I don't think they are sealing worth shit and they might be burned up now.

You will need to take everything to the machine shop to see what is still good and what needs to be replaced. Chances are you will have to replace some if not all the valves on #1. Going to need to recon the head. From the look of the chamber the piston looks to have hit it a few times but I've seen way worse. Going to have to check the crank to see if the #1 journal and weights are still in good shape. Likely you will have to turn the crank and get it rebalanced.

I'm sorry for your misfortunes. Hope this doesn't set you all back to much.

 

[jonseclipsegs]

And because my buddy and I thought it was so much other stuff and are dumb, we didn't even notice only one piston was up! As soon as I replied about the oil pan and the shavings not being in the oil pan I noticed that cylinder. I don't think there were shavings because we turned the car off as soon as it banged. I don't think his cylinder is messed up and were hoping its as simple as replacing the rod!

Thanks all for the replys!

 

[Maglin]

Usually with a rod failure of any sorts it almost never is a simple as just replacing the rod. IF it broke then it broke for a reason. The crank would most likely be bad or in the least need to be turned. Also broken rods tend to beat up a block and usually knock holes in them. That piston would also need replacing. I wouldn't chance it. They are $110ish each. Good luck man.

 

[GVR4592]

It looks like that cylinder was significantly leaner than the other 3. You might have a partially clogged injector.