AMC Two-Thirty-SCREWED?!?!

[Lucihale]

Just like any other time I've had a problem, I'll poke around and see what I can fix using Google and mechanical intuition; failing that, I come here. To the experts, for help in diagnosis, repair options and general aid. THANK YOU ALL IN ADVANCE!

:!: The Engine-
AMC 232 w/ Webber 2bbl, aftermarket intake and exhaust.

:!: The Situation-
Ran low on oil ( :redface: ) and since not a single gauge in my '73 CJ5 works, I stopped when I could tell it was getting too hot. (Smell, sound, etc.)

DIDN'T stall, seize, or complain. I pulled over, checked my levels and called for backup. Upon adding oil (and later a full oil change because the old oil was toast.) and startup, there was an awful knock.

Like 7 or 8 lumberjacks trying to escape my block... :bomb:

:!: Conditions of the Knock-
This knock (Click, Clack, etc.) happens once the engine warms up. It does not appear at idle unless it's been driven for a few miles. The sound appears louder, and more often when there is LESS load on the engine. (Down hills as opposed to up them) It also seems to fade at certain RPMs although I cannot tell you exactly which RPMs as none of my gauges work...
I'm NOT driving this engine now that I've gotten it home, because it still starts, and that gives me hope...

:!: My conclusions-
After some research both here and anywhere else I can find, I'm *guessing* that it's one of the following:
Bent or broken pushrod
Piston slap :-|
Worn camshaft
Blown main bearing

:idea: Currently-
I have the valve cover off, and I'm going through the pushrods as that is what I hope to god it is... But so far, I don't think that's it. I'm not sure EXACTLY what I'm looking for out of these, but they all seem straight, they all move regularly and I haven't found a snapped one.
I don't have a functioning oil pressure gauge, so I don't know if it's fluctuating (Main bearing) and I'm not sure how to test for the rest without a full tear down, which it's looking towards.

Guys (and gals) I'm pretty distraught as this is my daily driver! Pretty soon, my places of employment are going to stop being so understanding, but as of now, if I need to do a full rebuild I have some days to do it.
Should I buy a rebuild kit for 450 bucks? Or should I steal my brother's 4.0L '96 Cherokee engine? I hear the swap is pretty easy. Money is a huge issue of course, so I' m leaning towards rebuild.

ADVICE AND QUESTIONS ARE EXTREMELY WELCOME!!!

 

[Lucihale]

Update:

Finished going through pushrods. None are broken. None look bent.

 

[rdtj]

i really wish i could help you but i know nothing about motors. But i feel your pain.

 

[jps4jeep]

first guess would be bent push rod due to lack of lube, they tend to get partially siezed in the gally when the oil is missing . second would be a toasted bearing on the crank, again due to lack of lube. even running low on oil, as long as there is enough for th pump to pick up, you should not have damaged much.. were you that low?

have you run the motor with a stephescope? or with out the valve cover?

 

[superj]

pull the oil pan push the rods at the main bearings to see if any have any play. they shouldn't move, other then going around the bearing. should be no up and down or anything like that. pulling the pan should be fairly easy and then if you find a rod with some slop, its very easy to put new main bearings in with out pulling the motor. don't start it till you figure the issue out though because once it really starts pounding, just changing the bearings won't work because the crank might need turning then.

when our cherokee started making a light taping, i pulled the oil pan and replaced the mains anyways. wasn't the problem but the bearings had some weird marks on them so changing htem was good

 

[Lucihale]

Can't thank you guys enough, I'll tug off the oil pan tomorrow, and check the bearing. I'll also take pictures along the way so if anyone spots something I don't, we can address it then.

 

[Lucihale]

first guess would be bent push rod due to lack of lube, they tend to get partially siezed in the gally when the oil is missing . second would be a toasted bearing on the crank, again due to lack of lube. even running low on oil, as long as there is enough for th pump to pick up, you should not have damaged much.. were you that low?

have you run the motor with a stephescope? or with out the valve cover?

Didn't have a 'scope, but I ran it with the valve cover off. I pulled all the rods and looked at 'em and they seemed straight and complete. Oil pan tomorrow. I'll keep you guys up to date on it.

 

[Lucihale]

Also, is there a way for me to pull my tappets without a tappet puller? I've heard magnet, and I've heard wooden rod. Any advice here will be used in the morning as well!

 

[Tyler Bates]

You might want to make sure the oil pump isnt burned up as well I had a similar problem sounded like a knocking in the top end but with more load on it it stopped and the oil pump was weak or went out all together and sent a rod through the block

 

[Lucihale]

You might want to make sure the oil pump isnt burned up as well I had a similar problem sounded like a knocking in the top end but with more load on it it stopped and the oil pump was weak or went out all together and sent a rod through the block

Thanks! I sure will.

 

[jps4jeep]

magnet will work assuming they are not seized

 

[Lucihale]

Quick update!
It's been ****ing rain for over a week up here, but I got some days that I could open it recently. The tappets wouldn't come out with a magnet, so they're still in right now. I just started pulling the oil pan off today, and discovered that I need to uncouple the passengers side engine mount to give it enough clearance to come off. I gotta come up with a rig to hold that side up and I'll be back at it. I've recently concluded that my oil pump is probably fried, but I'm checking everything I can while I'm in there. I'll Let ch'all know what I find!

 

[Lucihale]

Okay! I stabilized my engine, removed the mount from the passenger's side and pulled the oil pan down. I remove the oil pump from the engine and have set everything aside as it looks like it's going to rain again. (If you haven't guessed, I don't have the luxury of a garage.

Here is where I'm going to need some help though. I'm not sure what to do to diagnose my issues.

What is going to tell me my oil pump is fried? (Other than it didn't seem to be pumping oil the last time I turned the engine over for a bit.)


Is it going to be easier to get to my tappets from down here?

What signs am I looking for on the note of wear and tear?

What should I replace now that I've gone through the trouble of pulling the oil pan?

Answering any one or more of these questions would be a HUGE help! THANK YOU GUYS!

 

[Tyler Bates]

The way I have always checked was in the engine and put a gauge where the sending unit is which will be a brass piece usually and located on the block thread that out thread the gauge in and let it run and see if the pressure is witin specs but since you have it out you can inspect the parts for wear and take it apart and do the same, but they rarely burn up or fail so most likely you just washed the bearings out

 

[Lucihale]

Another sunny day leads to more Jeep fixery. Found my 6th piston bearing to be down-right SLOPPY. But it's certainly what the terrible noise was. I'm going to check tappets when I finally get them out and I think my oil pump is fine (you're right Tyler Bates) but now that I went through the trouble I'm checking as much as I can. Thanks for all the help, and I'll let you all know when I get it back together.

 

[Lucihale]

Here are some pictures of the bad bearing. I just wanted an opinion on the minor scoring, and if that is going to mean that I need to get the crankshaft re-worked. It seems to have LESS scoring on it than these do.


They still FEEL perfectly smooth, but obviously, have been worn.

 

[jps4jeep]

Winner winner chicken dinner.

Regardless of being smooth, it's pretty worn and you can see the highs and lows. you can just replace that bearing, plasti-gauge it and se if you are with in tolerence, you SHOULD be fine, but if it were me, I would pull the motor, strip it, line hone the crank journals, polish the crank, all new bearings on the bottom end, put back together, new oil pump (your in there, might as well do it now) time it, and get another 30 some odd years out of it.

and while the block is at the machine shop, I'd re-ring the pistons and when you get the block back, hone the cylinder walls.

all in all, you do majority of the labor, shouldn't run more than $500-600 soup to nuts, then the motor will run another 30 some odd years

 

[Tyler Bates]

Here are some pictures of the bad bearing. I just wanted an opinion on the minor scoring, and if that is going to mean that I need to get the crankshaft re-worked. It seems to have LESS scoring on it than these do.


They still FEEL perfectly smooth, but obviously, have been worn.

If it were me Id either buy a new crank or have yours turned maybe .20 over and then you could get bigger bearings on it. But I agree since you have it torn down save your self the trouble down the road and do the rebuild you will have all new gaskets rings bearings everything and be done with it for a lot of years

 

[elevatorman]

Understandable not having a garage to work in definatly creates additional challenges(i have been there) But in agreement with all the other advice ,if you are at the point of checking bearings do a rebuild and before you fire up the new one-----------Get an oil pressure guage. Then happy 4 wheelin!