Rod knock on an engine with 4000 miles??????

[Green Machine]

Why Marvel Mystery oil in a new engine ? Isn't that some pretty thin stuff ?

[brad_man_72]

last monday my engine started knocking. i pulled the steel crankshaft out in 3 pieces.
try turning flywheel/crankshaft back and forth and see if harmonic ballancer moves the same.

hell i didnt even think a car could run with a broken crankshaft.

a few pics of the carnage in my album. 5.3 swap in progress.

[highperf4x4]

Originally Posted by brad_man_72

last monday my engine started knocking. i pulled the steel crankshaft out in 3 pieces.
try turning flywheel/crankshaft back and forth and see if harmonic ballancer moves the same.

hell i didnt even think a car could run with a broken crankshaft.

a few pics of the carnage in my album. 5.3 swap in progress.

Yeah I rebuilt a Ford 302 with a broken crank. We started it up just before I pulled it and it sounded awful. It ended up being the wrong year model crank for the motor it was in. Someone had used an early model 302 bottom end in a later model station wagon and had to use the late model balancer which was balanced different. Typical Ford crap.

[americanmusc1e]

Originally Posted by Green Machine

Why Marvel Mystery oil in a new engine ? Isn't that some pretty thin stuff ?

to thin down 4 quarts of 20w50 (which i run because i have a flat tappet camshaft)

[highperf4x4]

Originally Posted by americanmusc1e

to thin down 4 quarts of 20w50 (which i run because i have a flat tappet camshaft)

Your oil is only 20w. It's never any thicker than that unless it's extremely cold outside. That 50 only means that when it's "hot" is "equivalent" to straight 50w that's also hot. They use "fillers" to keep the 20w050 from thinning down much as it heats up. You sacrifice some lubrication for it.

I run straight 30w.

Also, thicker oil doesn't help a flat tappet cam. Lubrication and heat reduction does. A multi-grade oil has less lubrication than a straight weight oil. You can use a zinc additive if you're worried about the camshaft.

[special-K]

So,when are you going to look at the oil for metal.I keep saying this because you really need to know if it`s damage of improper assembly,as in beyond tolerances rom the get-go which is absolutely on the builder.I`ve had this happen.The bearings were .02 beyond.The guy took just a tad too much off and should have gone one more size under.

[americanmusc1e]

Originally Posted by special-K

So,when are you going to look at the oil for metal.I keep saying this because you really need to know if it`s damage of improper assembly,as in beyond tolerances rom the get-go which is absolutely on the builder.I`ve had this happen.The bearings were .02 beyond.The guy took just a tad too much off and should have gone one more size under.

as soon as I can, I have to get some oil to put back in there before i take the old stuff out, probably Monday or Tuesday, I'll probably take the truck in for a professional second opinion Tuesday. I wish it was something simple, but it doesn't look to be. the truck may have to sit until I get enough money to work on it.

[highperf4x4]

That's a bummer. Any chance of getting the builder to warranty the motor?

[americanmusc1e]

Originally Posted by highperf4x4

That's a bummer. Any chance of getting the builder to warranty the motor?

I doubt it.

[brad_man_72]

you're going to drive a knocking truck!!!!

[americanmusc1e]

Anybody want to make an offer on a '03 Honda Recon ES

here's the 4-wheeler and some of my truck

YouTube - Doughnuts etc..

[americanmusc1e]

I shouldn't have put that on there, nobody's gonna want to buy it the way I drive it

[piecesparts]

I haven't taken the time to check each entry to this forum, but definitely pull the fuel pump and check the arm that runs it from the cam. If that has a lot of slop it will sound like a rod knocking and only does it under load.

[truckdude239]

new motor oil is suppose to be changed at 500 miles then at 1500 mile and every 3,000 mile after. on a new motor it is best to go easy on the motor for the first 3k miles of its life

[faribran]

I shouldn't have put that on there, nobody's gonna want to buy it the way I drive it
BINGO

[special-K]

You only have to drain a little oil to test.You can always pour it back in.If there`s metal,you won`t be driving it anyway.If there`s none you just pour it back in.and,still shouldn`t drive it.The machining i`m talking about is on the crank and the bearings are sized acordingly.A builder could have lubbeb up on that and it woukd absolutely be his responsibilty.There would be no metal from damage,just beyond tolerance.
You say you cahnge it every 3,000 miles.How many 3,000s are in 4,000?That`s after a motor is broken in.You didn`t run it past 500 w/o changing your break-in oil did you?The next oil change should be at anither 1,000.then,go on the routine.
It sounds like you think you need to thin 20w-50.Not at all.20w is very thin.That`s what multi-grade means.It`s 20w and everything between 50w,depending on motor`s needs and environmental changes.We used to run one weight in the cold months and go to thicker oil in warmer weather.Now you don`t have to think about it.
If you ran the snot out of it rather than breaking it in along with running too long on thinned out oil I`d say you bought yourself an expensive lesson.

[americanmusc1e]

Originally Posted by special-K

You only have to drain a little oil to test.You can always pour it back in.If there`s metal,you won`t be driving it anyway.If there`s none you just pour it back in.and,still shouldn`t drive it.The machining i`m talking about is on the crank and the bearings are sized acordingly.A builder could have lubbeb up on that and it woukd absolutely be his responsibilty.There would be no metal from damage,just beyond tolerance.
You say you cahnge it every 3,000 miles.How many 3,000s are in 4,000?That`s after a motor is broken in.You didn`t run it past 500 w/o changing your break-in oil did you?The next oil change should be at anither 1,000.then,go on the routine.
It sounds like you think you need to thin 20w-50.Not at all.20w is very thin.That`s what multi-grade means.It`s 20w and everything between 50w,depending on motor`s needs and environmental changes.We used to run one weight in the cold months and go to thicker oil in warmer weather.Now you don`t have to think about it.
If you ran the snot out of it rather than breaking it in along with running too long on thinned out oil I`d say you bought yourself an expensive lesson.

changed the oil at a little less than 500 then again 2500 miles later when my odometer was at 6000. right now my odometer has about 7500 miles on it

[RustyParts]

I had a rocker arm stud that was worn on one side letting the rocker arm slide off the pushrod. The engine would idle but when I revved it up it would knock and loose oil pressure because the lifter was trying to come out of the hole. Easy to check out by removing the valve covers.

[americanmusc1e]

Originally Posted by RustyParts

I had a rocker arm stud that was worn on one side letting the rocker arm slide off the pushrod. The engine would idle but when I revved it up it would knock and loose oil pressure because the lifter was trying to come out of the hole. Easy to check out by removing the valve covers.

I've been having all kinds of rocker arm problems, I guess I should check that

[special-K]

It could be alot of things.But low oil pressure points away from most.Was the oil pump replaced?
I based my other remarks on the 4,000 mile statement.i guess it`s been knocking for awhile?
I wish I could check it out.I hope it`s not too serious.

[highperf4x4]

Actually break-in oil should be changed immediately after the first 25 minutes of breaking in the camshaft. You make sure your lifters are properly adjusted, start the engine (without excessive cranking) immediately bring the engine up to 3000 rpm and then vary the rpms between 2500 - 3000. This causes the crank to throw oil on different areas of the cam. Immediately after the camshaft break-in, you change the oil, change it again at 500 (when rings have seated) and after that, every 2000 - 4000 miles depending on your driving style.

I will say this right now, your problem was not caused by not changing the oil. It could be that the cam was not properly broken -in and the metal shavings are chewing up your mains/rods or like previously stated, the crankshaft was not properly ground or bearings not matched.

I'm getting the distinct feeling that this was not a "new" build??????

Are we talking about all new parts here and fresh machine work? Did you pull used crank and cam from another motor and just throw some new bearings on it? If it's a used cam, did you match the lifters back to the exact same lobes they came off of?

[americanmusc1e]

Originally Posted by special-K

It could be alot of things.But low oil pressure points away from most.Was the oil pump replaced?
I based my other remarks on the 4,000 mile statement.i guess it`s been knocking for awhile?
I wish I could check it out.I hope it`s not too serious.

oil pump was replaced with mellings m55 standard volume.

I started this thread when the problem started. The rocker arms have been giving me a problem for a while. at first I had 'em too tight and killed a lobe on #2 exhaust for sure, now I've been having a problem keeping them tight

[highperf4x4]

Originally Posted by americanmusc1e

oil pump was replaced with mellings m55 standard volume.

I started this thread when the problem started. The rocker arms have been giving me a problem for a while. at first I had 'em too tight and killed a lobe on #2 exhaust for sure, now I've been having a problem keeping them tight

Setting the lifters too "tight" won't kill a lobe. It only makes the engine run bad since the valves won't close.



1. if you lost a lobe then you should have pulled it immediately. It's throwing metal shavings everywhere!!!!!!!

2 If you have other rockers that are getting alot of lash in them, then you're killing more than one lobe.

3. sounds like you didn't break the cam in right.

When you first put the motor in the truck how did you break in the cam and how did you set the lifters? It's as easy as pie with hydraulic lifters and you shouldn't have to touch them again once they're set. If you had to adjust them after you ran the engine then your cam didn't get broke in right.

[highperf4x4]

I can tell by now that your engine is in bad shape. Even if it was a new build with fresh machine work, it's toast now. I can gaurantee you that you're out a cam and set of lifters for sure. If you keep driving it and you have stamped steel rockers then you're out a set of rockers and pushrods too. The beefier rockers like rollers or roller "tipped" might hold up longer but you'll probably find a pushrod or two trying to go through a rocker right now. I am gonna say this though, that knocking noise you think you hear is probably coming from the lifters. Still, as much metal as you've circulated through the motor now, I'd turn the crank again. If it isn't smoking yet then the cylinders are ok.

I'd pull the intake off the motor right now and see how many pushrods have slack in them and then run your finger around in the oil laying in the lifter valley and see if you find "copper" shavings in it. If so, your mains and rods are shot.

[Rudy67chevy]

sounds like my 02 chevy silverado