I think I broke my engine

If you do find it to be a rod bearing, make sure that all the oil passages are clear before reassembly. Maybe a chunk of crud blocked a passage, starving the bearing?

 

I haven't taken it apart yet so I'm just thinking out loud here. If I have to take the crankshaft to the machine shop to be ground, would I be able to take just the crank or would they need the piston rods as well? I'd like to not remove the head and pistons if possible.

 

The F134 has a forged steel crank, and it's possible to fix a rod bearing with the engine in the car. The symptoms sound like a rod knock, but your description of the sound does not. It's quite true, as Steve mentions in one of the first replies, that a failed rod bearing is the most common problem of this type.

I would spend some time and effort diagnosing what the problem is before I pulled the engine. What did you do to the engine for your restoration?

 

Engine parts and head went to the machine shop. Everything was hot tanked. Head was pinned, cylinders bored, and crank was turned. New pistons, rings, camshaft, valves, oil pump, bearings, seals, and gaskets. The machine shop installed the cam and valvetrain for me, I installed the crank, pistons, etc. So, pretty much everything inside the engine is brand new except the crankshaft and piston rods. I followed a book (can't remember the name but it is an "everything CJ" book) for assembly methods, torque specs, and procedures. I checked the crank for end play as per the book's directions.

The gasket kit had a rope seal for the rear main and I feared that it would leak...and it does. But the engine runs great, doesn't smoke, compression perfect, oil pressure perfect (or it was anyway.)

Again, I'm just thinking out loud. I know I need to diagnose it further before I jump to any conclusions. But I'm a project manager by profession so I tend to think through every possible path and task before I get started. That's the only reason I was asking about having to take the crankshaft back to the machine shop.

But I'm seriously considering pulling the engine anyway just so I can replace the RMS with a neoprene one that won't leak. That way, I can put it on the stand and inspect everything to determine the root cause.

 

OK I have some more information. I had a little time this morning to go out and start it and here's what I learned. When I started it up, the oil pressure came up slowly and I could hear it knocking. I tried removing the spark plug wires one at a time and no change in sound. Then, after about 2 minutes, knock went away.

The knock is now gone, engine sounds fine and oil pressure is normal at idle. However, when I rev the engine the oil pressure drops, which is backward of what it was doing the other night when the problem started. But I don't hear a knock anymore. The upper valvetrain sounds noisier (more chattery) than before but that could be my imagination, it still sounds OK in my opinion.

 

So sorry to hear this because I can relate very well. Almost the exact same thing happened to me with my Fhead. Sounds like there is still hope that yours might not be as bad, but even if it is, I can speak from experience that you will get through this and it won't seem so bad later.

Here is what happened to me...

http://www.earlycj5.net/forums/showthread.php?62088-My-first-jeep-56-CJ5/page3

I never 100% figured out what happened, but learned a few things more since the post in the link above and have a couple of leading theories.

1) My oil pickup should not have had a hole and oil in it. EricM gave me a spare he had (thanks again) and that is what is in there now. What I learned is that the empty cavity at the back of the pickup is so that the pickup floats on the oil in the pan. I think this is the first line of defense for the partially filtered oil system. Any dirt, etc, will go to the bottom of the pan, but since the pickup floats it gets oil from the top. In my case it sank and pulled oil from a lower location.

2) Like you, I had the machine shop assemble the cam and exhaust valves. This is a little different then the typical engine builds I've done since the valves are in the block. Well, in a typical engine build, I would get everything from the machine shop and clean it all real well before I start assembly. Well in this case, they started assembly and I just picked up where they left off. In later discussions with the machinist, we figured out he only cleaned what he had to clean for the things he assembled. He didn't clean the crank....neither did I. So the theory is metal chips, etc, that were in the passages were the cause.

The machinist I worked with was exceptionally cool. Like Tim mentioned, these engines have forged cranks and mine did need some welding to repair. Machinist also recommended (and I followed his recommendation) that the entire engine be disassembled and hot tanked to make sure all the debris was removed. He only charged me a couple hundred dollars for all of this (engine disassembly, crank repair and new bearings, and hot tank) because I think he felt bad too even though he was not at fault at all.

 

Be leery of the new oil pumps. On the 2A page, 3 members including myself have had them seize up and break cam and oil pump gear teeth. I was lucky and the only the oil pump teeth broke. If I were you, I would rebuild the original oil pump if you still have it and put that in and see what happens. Is the new pump a melling? Those are the ones we were have the issues with. We did prime them correctly. For whatever reason they lock up. That would be where I would start investigating.

 

Tomtom, great thread and our problems do sound incredibly similar. I did clean my oil pickup, it had tons of crud in it originally -- even bugs, which I found sort of odd. I took it apart and cleaned it very well in carburetor cleaner. I didn't notice any holes in it but I guess I wasn't really looking for them, either.

The machinist who did my work is very reputable and definitely knew what he was doing. I tend to trust that he inspected the crank very well.

Garage Gnome, unfortunately I did not keep my original oil pump. I don't know the brand but it came from one of the typical vendors, I think it was Kaiser Willys as I bought most of my stuff from them. It sounds like it would be worth my effort to find a used original pump and rebuild it.

Glenn, how would I check the oil pump relief valve? I looked at a diagram and it's a pretty simple device so do I just take it apart and inspect it or is there some sort of test procedure for it?

I'm going to inspect the bearings because even though the knock is gone, I know there has to be some damage somewhere. Engines don't make hideous noises for no reason. Again, I'm going to pull the engine anyway because I want to replace the rear main seal and I don't like working upside down. My goal is to have a 100% leak-free Jeep -- hefty goal, I know, but it's gotta be possible.

I've been asking a ton of questions but please don't think I'm being panicked or anything, I'm just trying to get educated. Again, I'm a project manager so running through every possible scenario is sort of engrained in me.

 

It's a mechanical gauge. I teed off from the electric sending unit for the idiot light and ran a copper tube to a mechanical gauge. It's possible that it is malfunctioning, which would mean I have two simultaneous problems. They're cheap enough (like $20) I may just buy another one to rule that out. I know it dropped oil pressure for real the other night because the idiot light was blinking as well.

 

The timing gears on an F-head can make a knocking sound similar to a rod knock.

 

I was going to pull the engine to replace the rear main seal and while I have the pan off, I'll look around for any damage. Someone told me not to turn the motor upside down on the stand unless I plan on doing a full rebuild. Not sure why that is. Obviously, I wouldn't turn it over with the oil pan on but once it is removed, why not flip it over to work on it more easily?

 

After you have removed the pan and flushed the engine from the bottom, then you can flip the engine. It's the very fine metal and abrasive grit in the oil that can lodge between piston and wall and else where if you flip with the pan on as not all the bad stuff runs out with just an oil drain.

 

I have some more information to offer. Got the engine out and it appears that my rear main isn't leaking, if it is then it's only a tiny bit. The oil leak was in fact transmission. I will pull the retainer cap and replace the seal. There is considerable end play in the transmission shaft. I've researched it and have gotten conflicting opinions -- some say that end play is normal others say there should be none at all.

I also found that the generator slider bracket bolt was loose. The nut had come off allowing the generator to shake back and forth. This may explain some of the noise I was hearing. Odd, though, that the belt didn't squeal. I still need to pull the oil pan and have a look but since the rear main isn't leaking and the oil pressure is back to normal, I'm thinking everything may be OK. It might have been the oil pump relief valve as suggested earlier, I'll at least take it apart and inspect.

 

that's good news man!!! by the way where do you drive that thing on Morgantown without getting run over.......bet it is super crazy there now that the kids are back in town.

 

Ain't that the truth, this becomes an entirely different town when the students come back. I try to stick to the back roads and avoid the mess.

 

If you follow rt7 far enough my old JEEP has seen every back road, logging road, cow path in and around the little town of Hundred.

I have been following this post.....Like I said I'm glad its not as serious as you first thought.

 

When I drained the oil, it looked very clean. Let it run over my finger while it was draining, it looked and smelled perfectly normal. I did not see any metal in the pan. Naturally, the oil pressure loss concerns me greatly. I'm hoping it was as minor as debris in the pressure relief valve.

Putting an oil pressure gauge in it is a blessing and a curse.