Number 2 Cylinder rod knock

Hello people. I am farily new to the whole rebuilding engine process. Recently I rebuilt my engine. I have driven it around 450 miles when I ran into some Rod Knock. I have detatched my oil pan and found that it was number 2 making the noise.

Now, I have taken the 2 nuts off the rod bearing, but i cannot take the cap off. i am worried I may damage it if I struggle with it too hard. So if there is anyone out there that could offer some assistance, that would be awesome!

Here is a video of my problem and where I am at with the project.
click

You can kind of see it moving forward and backward. Also, I am posting an image here for people who would like to see exactly what I'm talking about. The cap with the knock is the one without the nuts on it on the left.



Any help or advice would be appreciated.

 

[Brianawd]

Turn the crank so that the rod is at the bottom of the stroke. Once you have done that put the nuts back on the ends of the rod bolts and tap up with a dead blow hammer. That will free up the bottom cap. Once it is lose pull the nuts back off and the cap will come with it.

 

Awesome. I'll give it a try tomorrow morning. appreciate it.

 

Okay, I know this is going to sound stupid, but I am a complete noob, and the only way for me to learn is to ask questions.

I have removed the cap and have the bearing out. It is shot. There appears to be burning on the bearing and the cap, so I assume that the connecting rod is burned as well. Do I have to replace the whole assembly or would it be possible to just replace the bearing and put the cap back on. There doesn't appear to be any unnatural grooves or striping on it, it just looks black, but I haven't gotten any brake cleaner yet, so it may just be the oil on it.

The bearing looks as if it wasn't seated properly because the edges have been worn away and I found a nice little chunk of metal. If ya'll want pics I can post them.

Also, if I do have to replace the connecting rod.... how would I go about doing this? I haven't inspected it just yet as the crank is in the way. Can I just move the piston up and move the rod to the side? I dont' want to damage anything further, that's why I'm asking before-hand.

 

[iceman69510]

Either the crank or the head have to be removed to get the piston/rod out. Sorry, won't fit any other way.

The rod may be junk, depending on how hot it got. Really probably needs to be checked for roundness unless there is no sign of heat damage. If it is damaged and you don't have it checked, you may damage the bearing again quite soon.

I just had my engine lose rod bearing 3, and I could not determine why. Just finished re-rebuilding it, so I am planning on better results this time.

 

I am about to check the rod now. I got a new bearing, it looks like it should be alright, but i'll find that out soon. I'll update when i have further details. The cap looked okay. a little darker than it should be, so I am going to see what the rod looks like.

If I feel it's okay, I'll slap the new bearings in and I'll run it. If it happens again, I"ll remove the crank and have it turned, and get a new rod and bearing. Which will be lame, but ya do what ya gotta do with these engines.

thanks for the help guys.

 

[Wizardawd]

Rod is more than likely junk already. Once you hear the rod knock, it is already started to egg-shape the journal end of the rod. Which...will cause the rod cap to be difficult to come off. And putting another bearing in will not work since it will just spin the bearing. And the discoloration is only a further sign of heat/distortion.

Hate to tell ya, but the new bearing more than likely won't last long at all. Maybe a day or 2 at most. In the end, the head has to come off and that rod and maybe even the piston will have to be replaced. Most than likely the crank may be ok as long as it's in spec. You can check it in the car if you have a micrometer, just check it in multiple spots to make sure it's not out-of-round.

Wiz

 

Thanks Wizard. I'll check it out because I have already re-assembled it. You're most likely right because nothing with this car has been easy. I may just sell the beast when this project is completed. But thanks for the words man.

 

[NYC86ZC]

FWIW...i rebuilt my built honda engine after the PO oil starved it and had a main bearing turn. I used a new crank, but since it was a budget build i reused the eagle H beams. 3 looked fine, but one was discolored from the heat. To keep with my budget build plan i put on some new bearings and put it all back together again. It's been fine for the past 5k miles with no issues thus far. I also turned up the boost to 18psi and the only problem I'm having now is my clutch can't hold.

On the flip side a friend had a rod knock on his 4g63 so he threw in some new bearings. It was fine for about 3k more miles until it started to knock again. The rod ended up beind out of round.

IMO, if you hear a knock the crank is probably garbage unless you get it cut.

Good luck.