Rod knock?

Travis

Travis

Member
Hello all. Just got my Scout II alvie after sitting for three years or more. And have a rod knocking. It runs so smooth and fires up very quickly. No smoke out the exhaust. My question is. My friend said "he a mechanic" that he can drop the pan and then pull the crank and just grind it down and put new bearings in and it should be good for a while. He also said the compression was good also. Whats everyone take on this. Cheap and easy. Or pull the motor and go through it? Thanks for your time.

Travis
 
I seriously doubt you have a "rod knock"!!!! Nearly unheard of regarding IH iron unless, it's been run completely out of oil and overheated.

Don't do anything right now. I have to leave for the day but I will be back and suggest a diagnostic process. 90% of the time it's a collapsed lifter(s), most especially after an IH I-4 or sv motor has been sitting unrun for months/years.

Your friend is "kinda" correct...only it's not that simple. A reground crankshaft is a procedure used in any correct engine rebuild...but only if needed after measuring all engine wear components.

In the meantime, download and review the attachment in post #31 in this thread:

http://www.forums.IHPartsAmerica.com/carb-tech/739-rebuilding-2300-list-2977-carb.html

That will explain the big picture.
 
My friend says there is no way its coming from the valve covers. Its a rod knock. He's heard them many times before in his life.
 
Thanks for the info but it is greek to me. I showed my friend and he is sure its a rod. Climbed under the Scout while running and its coming from under the oil pan.
 
No dissrespect to your mechanic friend intended here, but I wouldn't be so hasty to jump to that conclusion. Mike knows these engines like few others alive. A v8 is a v8 is a v8 in many regards, but these IH versions do have enough unique quirks in them that can throw off folks who are more used to other makes. I have another idea for you to check out. Years ago I had to remove my 727 trans for a rebuild. After the bench work was done I did the reinstall. After double-checking to make sure I'd hooked everything up propely, I fired up the engine, added fluid and put the tranny in gear. Everything was working great. It wasn't long afterwards that I began to notice a knocking noise which increased and decreased in response to throttle position. It was very hard to tell where it was coming from, but it did sound like it was on the bottom end. I sought advice on the subject over on the bb and most of the feedback I got was rod knock or wrist pin etc, etc. Pretty bleak stuff. Then I had a relative who was certainly no machanic, but knew his way around machinery listen to the engine and the knocking noise. He suggested I remove the transmission inspection cover and make certain that my flexplate to torque converter bolts were all tight. I did, and sure enough I found a couple that had worked a little loose. This time I put them all in with loctite and made extra sure they were all torqued properly. Buttoned everything up, hit the key, no more knocking noise. That was over 7 years ago. Just something you can check on your own quickly and easily. It could really be that simple. I hope it is.
 
Scoutboy, no disrespect takin. And I did not me any disrespect to michael, he is very knoledgable and helped me a lot in just these first few months as an IH owner. Just all the journal thickness and oil paths makes no since to me since I have never toar down an engine myself. I will have my friend check the bolts on the flex plate also. The problem is before doing all the lubing he talked about in that link I had it running already. So I hope all is not lost. I guess if I have to jump ship I do have a 350/350 and NP205 sitting around to swap in.
 
Travis, just a thougth here. Check the fuel pump lever spring. I've seen this broken and it sounds like a rod knocking. The pump works off the lobe on the front of the cam and the noise travels down through the bottom. Those guys are right about v8's they have their own ghostly noises. Also have you done a oil pressure test. The galley is on the left and the plug behind the oil filter is the easiest one to acess. You can remove the sender but no need. Specs say 10 lbs min at idle hot. These engines are beastly on the bottom end and tough as hell. My 304 was worn slap out all bearings to the brass and still no knock.but the crank was still in spec so we put in plus .002 rod bearins and plus .002 mains. These bearings are hard to find but we have an old machine shop here that used to build these motors for a foundry here and they sold us there nos IH stuff.
Let us know what you find
 
Now that you mention it the fuel pump quit working and we had to use an electric one to bypass to get it running. Thanks for your help.
 
Travis: here's some noise guidelines. I've had engines through the years that at sometime or another has had them including the one now in the 800 I use a lot.

A loose piston pin gives a sharp rap at idle. You'll hear it from the pan area as though it was up in the block. Shorting spark plugs one at a time will zoom you in on the offender by the noise going away when the cylinder with the bad pin is shorted out.

A metallic knock when idling or slowing the rpm could mean a worn or loose connecting rod bearing. It'll go away with the engine under load, and May even dissapate a little when things are up to operating temps. Shorting spark plugs one at a time will help you hone on which is which. You'll definetly hear that from the pan area. I had a Ford truck with that one. It was knocky when cold in the morning and would go quiet when accelerating. Then it would pretty much diminish when the engine got to oper. Temps. I just soft footed it until the truck went away.

A flat slap when increasing engine speed indicates a loose piston or one with a collapsed skirt. Pretty noticable when the engine's cold, but gets way less when hot. I have a running 266 with piston slap. Been that way since 98 or 99 when I got it. Doesn't seem to hurt anything, I just baby it when it's cold.

Loud clacking, especially when first starting up the engine, or clicking or intermittant variations of such mean faulty lifters. There's a lot of us that have that when our rigs sit for a time.

I know you're new to this and how to define a slap from a rap or knock over the internet is impossible. But there is a scenerio associated with various noises and where in or on the block they come from. Over time you'll tell the difference.

Best to wait until Mike m. Runs you through the "routine". It's like a pre-orbital flight check/ countdown that covers all the essentials for reviving old iron that's sat for awhile.
 
No one has mentioned that loose carbon in the cylinder could make a horrible noise that could sound like a knock have had it happen before and it is confusing.
 
Not to highjack this thread, but I have a newly rebuilt 304 on my engine stand waiting for me to catch up with the chassis. It will be six months before I will have the chance to start and run it. Do I take from michael's comment that the lifters will be damaged by sitting that long?

Pineneedle
 
Well my friend went on vaca until this sun. So no work will be done until then anyway since the Scout is at his place. It will not hurt to pull the pan anyway would it? Can it be done with the engine still in.
 
Nope, won't hurt anything to have a looksee. Yes, you can r/r with the engine in. Unless you've got a suspension lift, you'll have to raise the body up with a highlift jack so you have enough clearance above the axle to get the pan out. While you've got it out, check for any warps or distortion from overtightening and re-shape. Make sure you use a new gasket when you put it back on and don't overtighten the screws.
 
A collapsed lifter in one of these pos motors will bang just like a rod.

I'm doin' my third diagnostic right now for this same issue!

Why pull a pan if ya don't need to?

Unless yore gonna pull the motor and build it right, yore wastin' time, effort, and cash.

Pull a valve cover(s) and prove I'm wrong, then everyone will feel better.

If ya insist on waistin' time, then pull the pan and use plastigage on every rod cap/journal, that will give ya plenty practice in rotating tha crank and learnin' how to use a torque wrench.

As for an internal engine wear item, piston slap is far more prevalent on sv motors than a rod bearing issue. Same for pison pin knock on only one cylinder.

Pullin' a pan right now is the shotgun approach.
 
Pineneedlejohn...yore sitch is totally different from what we're talkin' here. Yore motor was built correctly with prelube and has not been run! And we know the cam bearing sitch in yore motor...remember that's what we started jawwin' about near two years ago!

For the rest of ya...john and I have been talkin' durabond cam bearings for many moons, he's had two sets of durabonds that were not manufactured correctly, he had to correct the second set himself after a re-install by his machine shop. Since then, every set I've seen installed was not correct, but it's an ez fix if yoiu know what to do. Ya never accept stuff like this from the machine shop without personal verification! And john had an eagle eye, especially after studying all available information regarding this issue!

When you are ready to light tha motor off the first time...I'd definitely follow that process I posted so ya can prime/fill all "cavities" (including lifters and lifter gallery). But you can do that right now much easier with the engine on the stand....and ya can do it any time ya wanna watch them slippery molecules run around in there!

We need a video on this forum of a properly oiling I-4 or sv rocker assembly. I have some stills but if we have video, it's much easier to see! Next time I have one runnin' for this issue, I'll do a webcam video capture and post it.
 
Thanks for the response, michael. I am glad you directed my attention to this forum. It has a really fine conviviality, no pretense, and great information. I intend to continue to be as active a participant as I can.

Pineneedle
 
Thank you michael. I will tell my friend that as soon as he gets back from vacation. So your saying pull the valve cover first and you will be able to tell right away. I am no mechanic. And I understand that you know these in and out like no other. Thanks again.

Travis
 
Ya got it travis! Just pop one side (pick the one that sounds like the noise "might" be coming from) and run the test looking for oil ooze at all important locations on the rocker assembly. And if it's a collapsed lifter, then I can tell ya exactly how to figger which one. And then we'll need to diagnose "why".

Once we eliminate all possible "top end" lubrication points of concern, then ya can pop the pan and plastigage if need be!

But always...when doing diagnostics like this, ya wanna be careful and not disturb the evidence...don't pour any oil on the rocker assembly, etc. We need to hear the noise, then diagnose from where it's originating...otherwise it's a shotgun/crapshoot!

By the way...I gotta 196 in our s80 right now with the exact same issue/noise. I've done all the diagnostics after I got it running after sitting for 14 years inna blackberry jungle. #1 cylinder knocks like hell onna cold start, sounds just likea diesel! After getting fully up to temp (at least 30 minute run time), the noise goes away.

Diagnosis?? A "collapsed" piston skirt (very slight), resulting in piston slap. According to gearman dave who worked in the IH corporate regional engine rebuilding facility, this was a common issue on the non-emissions 196 motors due to the material used in the pistons for a few years. The same issue May occur with the early 392 motors since they shared the same pistons. And it only occured after an engine was run for a period of time in an "overheat" condition, it's not "wear", it's an actual deformation of the skirt.

Both Jeff and bromike have heard/diagnosed the same thing on this motor! They both thought it was a diesel conversion under the hood!
 
Hey michael, just thinking towpainter3 earlier in this thread said check the fuel pump. Well my fuel pump is not working. What do you think about the fuel pump lever slapping around? Thats a fast two bolt and its out of there right? Just asking.
 
Sure travis! Ya gotta replace it anyway!

There are several different oem-style mechanical pumps for these motors, you need one that's definitely for the Scout II application so that it will clear the "side-type" motor mounts.

These fuel pumps do not use a "pushrod" to actuate the pump like a typical chev/sbc. The pump lever is operated directly from a fuel pump lobe on the camshaft.
 
Ok, I owe michael and you all an apology. Well really my friend does! I told him what michael said and he told me he has been doing this for almost 30 years and bla bla bla. He was actually mad at me. So he came back from vacation and decided to put a quart of tranny fluid in with the oil when he change the oil and filter. Ran the motor for only five or ten and the knock went away. It now has not came back for several days. And he did nothing else. Never pulled the pan or covers.

Funny though cause he ran a compression check before he got it running, and it was good. Lubed all cylinders with oil too. He was not as thorough as that document you sent michael. But he did do some things to make sure it was ready for a fire up. Anyways, thanks again for your help and being adamant here. To some heat from my friend, but he will listen when I tell him now.
 
No apology needed travis!

And not to rub it in...but yore "friend" don't know squat about IH motors or he woulda seen/heard/known about this common issue if he's worked on crapball trucks for 30 years! But very few folks are still alive and workin' on this schnizz and there is no market for doing so except amongst us hobbyists and the few pros left doing it!

In this same forum, I've started up a new thread regarding this same issue. Since you first posted this, I've been flooded with emails and more than a few phone calls regarding the same thing!

We're gonna step through this whole process and try and address all the side effects of a non-oiling/poor-oiling engine. When we're down with that, there will be no excuse for anyone not being able to diagnose and correct I-4/sv engine lubrication issues. And...there is no magic bullet for that other than cleaning up stuff and replacing worn out parts!

We're really happy this worked out for ya without droppin' the pan and spendin' needless dinero!!!
 
Hey whats your take on the tranny fluid in with the oil for a bit to clean up oil flow. If the knock went away I lucked out and oil resumed flow. Or should I still take your steps and make sure.
 
You asked travis...here's what is happenin'!

Tranny fluid, rislone, sea foam, marvel mystery oil, etc. All act as solvents when mixed with crankcase oil. Their viscosity is very light...approximately the same as 5 wt. Motor oil on the motor oil "viscosity" scale. Same thing as using any of the so-called "motor flush" treatments (that product is actually naptha/mineral spirits mixed with a bit of lube oil). Regarding my personal engines, I always use the gunk-brand version of motor flush at each oil change, been doing that on old, unknown quality motors for the last half century! It works over time and does not break loose a buncha grunge immediately (ya do not want that to happen!).

I'd venture that your issue at this point was simply a so-called "stuck" hydraulic lifter....badly stuck as in...collapsed. After some run time, the solvent action simply attacked the varnish deposit in one lifter that was "stuck". That allowed it to kinda resume "normal" operation.

The tranny fluid deal is just an oldtimee deal. Same for pouring tha schnizz through the carb with engine runnin' at fast idle, defintely kills all the skeeters inna half-mile radius, but "might" provide just enuff solvent action to attack a partially varnish-stuck intake valve also. But in IH crap, stuck valves are caused by lack of lubrication, which all comes back to the non-oiling rocker assemblies!!! When a valve partially "sticks", then the lifter/push rod/rocker clearance is excessive, resulting in that heavy bangin' sound ya had...not just a light "tick" that goes away once the lifters pump up after the engine has been sitting a while (like overnight??).

So...are ya outta the woods right now??? No! 'cause ya still don't know if the rockers are oiling! If they are all oiling properly, then you will prolly be ok for a while, if they are not...then history will repeat itself!

Pouring schnizz outta can or bottle cannot "fix" anything. It can be used in a "preventative maintenance" manner however. Same as drinkin' three beers onna mt stomach, make ya feel better, but don't fix yore brain chemistry!
 
Just an update for you michael. Its been a while since I have been on this thread. I have changed the oil a few times and no more knocks except when driving down the freeway at high rpms. I did some reading and heard other people saying the same thing. I did what was sugested and put an extra quart and a half in and no more knock. So I guess its pumping out of oil like people have said. I appreciate all your help. Thanks
 
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