so heres the deal this might be a little long but PLEASE bear with me and help me figure this out.
heres the history of the motor.about a year ago i rebuilt it after a spun bearing on the 3rd cylinder's connecting rod. the bottom end was completely rebuilt with topline parts, the block was honed, hot tanked, decked, and crankshaft and rods were machined. there was no wear on the cams or head so i replaced the valve stem seals and did everything by the book. it started on one crank of the starter after i put it together and i broke it in under 3k rpms for the first 3000 miles. after the 3000 mile mark i took it down the beltway and topped it out and it ran beautifully. i came home the next day and it was smoking out the exhaust at idle and soon after suffered a blown head gasket. even with these problems it still had no performance issues what so ever.
i purchased a used head from a reputable shop (light speed performance) here in houston and sent it off to the machine shop, had it milled, pressure tested, checked for clearances and rebuilt. i pulled the old head off put the new one on, changed the timing chain, and immediately suffered performance issues after start up. it was fine from idle to 3k and after right around there performance wise fell flat on its face. it still smoked on idle and i tried everything i could think of to figure out what was wrong with it. a compression test showed all the cylinders were good and i rechecked my valve and igntion timing several times. so prom weekend i went to galveston and drove it up and down the beach a couple times and the next day i got on the freeway to come home got about 30 miles and the #3 connecting rod bearing spun again!
so it sat for a while and i just pulled the ka out and stripped it down and noticed gold metallic flakes all over the bottom of the oil pan (which i had just thoroughly cleaned when i changed the timing chain) and every lubricated surface on the inside of the engine was scored. cams, bearings, cylinders, PISTON SKIRTS, and crankshaft (to a lesser degree) were pretty tore up. i found a larger piece about the size of the end of a pencil eraser and it looked a lot like the same material the throttle butterfly is made of (brass im assuming). and strangest of all in the combustion chambers every cylinder showed signs of running lean except the #3 cylinder which appears as if it was running incredibly rich.
i am thoroughly stumped on what would cause a perfectly rebuilt engine to self destruct like this. and i sure as hell cant figure out what is made of brass that could flake off into my oil pan like that.
i have high resolution pics but dont know how to post them
thanks in advance,-jason
spun bearing 5000 miles after rebuild! help!
Re: spun bearing 5000 miles after rebuild! help! (hpdrumakk)
Did the get a new engine light come on? (AKA... the oil pressure under 3psi warning light.)
you probably didn't break it in right.. you're not supposed to run it softly.. you're supposed to break it in like you're going to drive it... hard... that way everything seats right.. if you keep it under 3k rpms, the rings will seat like that, and when you go over, it's going to **** things up, (that could be the metal flakes?).. and loose power... but that probably has nothing to do with a spun bearing... just a thought...there was a breakin guide around here somewhere...
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deviousKA
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Break-in depends on the cylinder wall surface and ring type. Bearings do not care, if there is a problem it is going to show up no matter what.
Check your crankshaft oil passage plugs, always remove the factory nissan crank plugs and have threaded allen plugs installed.
I dont have a guess as to where that chunk of brass came from, check your distributor/oil pump drive gears?(steel, but may appear to be brass) It may be possible that your crank was thoroughly cleaned (passage plugs removed) and your machinist inserted brass plugs (not nissan original).
the brass/copper shavings in your oil is from the bearings (copper), most likely due to low oil pressure (crank plugs falling out).
My guess.
Check your crankshaft oil passage plugs, always remove the factory nissan crank plugs and have threaded allen plugs installed.
I dont have a guess as to where that chunk of brass came from, check your distributor/oil pump drive gears?(steel, but may appear to be brass) It may be possible that your crank was thoroughly cleaned (passage plugs removed) and your machinist inserted brass plugs (not nissan original).
the brass/copper shavings in your oil is from the bearings (copper), most likely due to low oil pressure (crank plugs falling out).
My guess.
wow first off i gotta say i didnt think so many people would respond and im sry i didnt get back to this sooner ive been at work.
as for the oil pressure issue the idiot light didnt come on and i put a new pump on that was provided with the topline rebuild kit. it came assembled to the lower timing cover brand new so i didnt have a chance to screw any of that up lol
i checked all the sprockets, distributor, chains and everything checked out ok so i dont think the shavings came from them. however i havent taken apart the oil pump yet so i dont know about it
deviousKA what are these crankshaft oil passage plugs youre talking about?
is there a thread on breaking in engines? if not im making one
im gonna try and get some pics up here
o and i really appreciate everyones input keep it coming!
Modified by hpdrumakk at 9:02 PM 10/29/2005
as for the oil pressure issue the idiot light didnt come on and i put a new pump on that was provided with the topline rebuild kit. it came assembled to the lower timing cover brand new so i didnt have a chance to screw any of that up lol
i checked all the sprockets, distributor, chains and everything checked out ok so i dont think the shavings came from them. however i havent taken apart the oil pump yet so i dont know about it
deviousKA what are these crankshaft oil passage plugs youre talking about?
is there a thread on breaking in engines? if not im making one
im gonna try and get some pics up here
o and i really appreciate everyones input keep it coming!
Modified by hpdrumakk at 9:02 PM 10/29/2005
Re: spun bearing 5000 miles after rebuild! help! (hpdrumakk)
I've been told topline isn't good at all, from both honda,nissan guys.A local turbo ka used a new timing chain kit from them and a bad guide failed caused havock, rod went thru block. I would examine every topline part closely:squint
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deviousKA
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The oil passage plugs I mentioned plug the end of the diagonal oil passages that are drilled into the crankshaft. These are located on the journal side (as in, opposite the counter weights).
On the ka24e these plugs are small hardened steel balls (ball bearing type). They are held in place by some punched over crankshaft material.
These are somewhat difficult to remove for a machinist doing a complete crankshaft cleaning (which they should). They are very difficult to drill out. Once they are removed, replacing in the same fashion is also difficult (and prone to failure). Because of this, the machinist may use a different method to plug the passage, brass cold plugs, flowed lead insert, or threaded allen headed plugs are sometimes used.
Threaded allen plugs being the best method, least prone to failure and provides ease of crankshaft cleaning in the future.
Topline is a repackaging brand, they do not make any of their own parts (they may, but at least 90% is repackaged brands).
Some of their parts are ok, but most of the problem for an actual reseller or rebuilder is that you will not get the same parts in each kit (whatever kit it may be). Their timing kits are poor at best, always buy nissan/OSK.
On the ka24e these plugs are small hardened steel balls (ball bearing type). They are held in place by some punched over crankshaft material.
These are somewhat difficult to remove for a machinist doing a complete crankshaft cleaning (which they should). They are very difficult to drill out. Once they are removed, replacing in the same fashion is also difficult (and prone to failure). Because of this, the machinist may use a different method to plug the passage, brass cold plugs, flowed lead insert, or threaded allen headed plugs are sometimes used.
Threaded allen plugs being the best method, least prone to failure and provides ease of crankshaft cleaning in the future.
Topline is a repackaging brand, they do not make any of their own parts (they may, but at least 90% is repackaged brands).
Some of their parts are ok, but most of the problem for an actual reseller or rebuilder is that you will not get the same parts in each kit (whatever kit it may be). Their timing kits are poor at best, always buy nissan/OSK.
Re: (deviousKA)
hmmm didnt even know there was such a thing.... ill definetly check that tomorrow.... what really stumps me is why 3 cylinders ran lean and one ran rich and how it just so happens to be the one with the spun bearingdeviousKA wrote:The oil passage plugs I mentioned plug the end of the diagonal oil passages that are drilled into the crankshaft. These are located on the journal side (as in, opposite the counter weights).
On the ka24e these plugs are small hardened steel balls (ball bearing type). They are held in place by some punched over crankshaft material.
These are somewhat difficult to remove for a machinist doing a complete crankshaft cleaning (which they should). They are very difficult to drill out. Once they are removed, replacing in the same fashion is also difficult (and prone to failure). Because of this, the machinist may use a different method to plug the passage, brass cold plugs, flowed lead insert, or threaded allen headed plugs are sometimes used.
Threaded allen plugs being the best method, least prone to failure and provides ease of crankshaft cleaning in the future.
Topline is a repackaging brand, they do not make any of their own parts (they may, but at least 90% is repackaged brands).
Some of their parts are ok, but most of the problem for an actual reseller or rebuilder is that you will not get the same parts in each kit (whatever kit it may be). Their timing kits are poor at best, always buy nissan/OSK.
the oil pan is insane though it looks like someone poured a bottle of goldschlager in it and all the alcohol dried up
another thing that bugs me is that the cams are scored under the caps. like on every single cap there are two thin gouges that go all the way around and they are the exact width of the hole the oil comes through.
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deviousKA
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Re: (hpdrumakk)
Yes only two.
I do not know where that chunk that you describe came from, but all of the damage that you see to your engine and the flakes in the oil is from your bearings. When the debris is pumped through the engine it is like a grinding compound on all oiled surfaces.
I do not know where that chunk that you describe came from, but all of the damage that you see to your engine and the flakes in the oil is from your bearings. When the debris is pumped through the engine it is like a grinding compound on all oiled surfaces.
Re: (deviousKA)
ok i thought the filter would have caught all the shavings before they got any further. damn i need to seriously reevaluate the use of walmart filters lol!