L3250 noisy valves more than a simple lash adjustment

J03bota

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Nov 28, 2016
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The external oiling mods described are fairly elaborate compared to the by-pass line suggested. I have installed these on older push rod engines with good success. In some cases it is considered a performance mod when heavy springs and high lift cams are installed.
Every installation I made used existing plugged cross drillings to go from the main oil gallery in the block to the oil feed in the head. Removed the plugs installed 90 deg compression fittings with a 1/8" copper feed line between.
Jeff
Not sure if I'm following you exactly but I noticed that there are unused ports on the block. If one of those ports is oil I could use it as my main oil feed to an external port on the head as you pointer out? Heck, I could reuse the oil sensor port as my main feed to the head if nothing else was available right? My oil gauge is showing the sensor port pressure to be about 55 psi.
 

rbargeron

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Internal oiling passages in a block or head are drilled from the outside in the long and short directions, with the access holes later plugged. There might be pictures or drawings that show the V1902DI's lube circuit in the engine WSM.
 

J03bota

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Internal oiling passages in a block or head are drilled from the outside in the long and short directions, with the access holes later plugged. There might be pictures or drawings that show the V1902DI's lube circuit in the engine WSM.
Thank you Dick. I don't recall seeing drill pictures in the WSM but that doesn't mean that there not there. Will look again.
i can always pull a plug out of the block and turn the engine over. Maybe I'll catch a break and find a working oil Port on the Block that is near an oil port on the head
 

eserv

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Thank you Dick. I don't recall seeing drill pictures in the WSM but that doesn't mean that there not there. Will look again.
i can always pull a plug out of the block and turn the engine over. Maybe I'll catch a break and find a working oil Port on the Block that is near an oil port on the head
I would want to know what is wrong that is preventing oil from getting to the rockers before I started re-engineering the engine!
 

200mph

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eserv, See post #46

After seeing the dry running rocker arm assembly and knowing that this very same problem existed before I rebuilt the engine I believe I know what the problem is when the Machine Shop had my engine parts the owner called me and told me that there was a pretty big hole that had been patched just to the upper left of the dipstick apparently when the original owner spun a bearing piston Rod number 1 also went through the side of the engine. he said the good news is it did not touch anything it missed everything but I am willing to bet it damaged the oil passageway leading to the Head
 

100 td

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This sounds like an oil flow/pressure problem big time to me, why did the engine fail previously, low oil flow?
... getting about 50 to 55 lb of pressure and it does not vary as I change RPMs.
I hazard a guess that at 55 psi the relief is possibly bypassing most of the oil, so no flow anywhere else!
With a repair done like that, I really wonder where else oil is not getting to? :eek:
Me too!
Had the crankshaft machined and main bearing no.1 welded and machined back to std bearing dimension.
Maybe lacking oil here too!
Back to square one if it was me, don't waste anymore time, pull the block and get it fully checked, as well as the head, all oil passages. Each passage individually!
 

JeffL

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Not sure if I'm following you exactly but I noticed that there are unused ports on the block. If one of those ports is oil I could use it as my main oil feed to an external port on the head as you pointer out? Heck, I could reuse the oil sensor port as my main feed to the head if nothing else was available right? My oil gauge is showing the sensor port pressure to be about 55 psi.
Yes, you can use the oil pressure port with a Tee fitting and have the oil feed and gauge. The oil pressure is holding at 55 psi because the relief valve is working holding the max pressure in the main gallery to 55 psi. It does not reduce oil pressure in the engine beyond bleeding off excess oil to hold at max pressure. If the valve was not in place cold oil pressure could reach 200+ psi. This would blow out cup plugs and gaskets. Does the pressure reduce at idle when oil is hot?
After reading back thru the posts; I would recommend finding the reason no oil is reaching the rocker shaft. Is there a blockage or a worn bearing?
Jeff
 

BAP

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Better to find the original problem and fix it then to apply a Bandaid solution and ruin something else.
 

North Idaho Wolfman

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Pull the motor, drain the oil, strap it to a pallet, ship it to me via fastenal, and I'll go through it 100% and your only cost would be parts and shipping. ;)
 

J03bota

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Pull the motor, drain the oil, strap it to a pallet, ship it to me via fastenal, and I'll go through it 100% and your only cost would be parts and shipping. ;)
Really? I'm in complete shock right now. :eek:
I just may take you up on the offer.
I feel like I'm so close. I just plowed 15 in of snow like it wasn't even there for god sakes.
 
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North Idaho Wolfman

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Really? I'm in complete shock right now. :eek:
I just may take you up on the offer.
I feel like I'm so close. I just plowed 15 in of snow like it wasn't even there for god sakes.
Using the tractor that has the motor in it? :eek:
If so please stop, your going to do more damage to it. ;)
When you don't put any oil in the top end you can damage the rocker assembly, valves, lifters, cam, valve guides.
 

J03bota

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I plowed the snow a few weeks ago just after I completed the rebuild and got the Hydraulic pump working before we all came to the realization of a dry head
Will not be using it anymore until it gets fixed
Thank you NIW!
 
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North Idaho Wolfman

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I plowed the snow a few weeks ago just after I completed the rebuild and got the Hydraulic pump working before we all came to the realization of a potentially dry head
Will not be using it anymore until it gets fixed
Thank you NIW!
Phew... And yes it's a valid offer. ;)
 

J03bota

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Nov 28, 2016
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Re-looked at the oil flow diagram and now understand the added role of the idle gear. One thing that I could do that wouldn't be horrible is 2 check the port starting from the head then work my way down through the block toward the idle gear. Who knows I may find an old blockage that the machine shop didn't clear out. If no blockage then I'm probably screwed unless I can find something coming from the oil pan Which again I'm probably screwed because it will require me to take the front end off and if I take the front end off then I might as well take the gear case cover off
 

JeffL

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Jan 8, 2016
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Check everything including the rocker shaft. One thing you can do that might reduce the work; pull the oil plug on the lower left front corner of the head and start the engine. If oil shoots out the blockage is above the plug. Shut the engine off as soon as you know the answer. Jeff
 

J03bota

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L3250DT
Nov 28, 2016
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Southern Seacoast New Hampshire
Hello all, with help from rbargeron, I discovered why oil was not being fed to the cylinder head. The oil Port on the head needed to be aligned to a hole in the rocker arm shaft. If you don't turn the rocker arm shaft just right the oil is not fed into the assembly.
After confirming that oil was being delivered to each rocker arm I re-adjusted the Lash on all valves, put the valve cover back on and started the tractor. The ticking noise is still there - Loud as ever. rbargeron believes that it is likely a flat spot on the camshaft.

Plowed 4 inches of snow last week and noticed that the tractor was smoking more than I remember. My wife brought it to my attention. light blue smoke. Smelled like burning oil.
- Likely related to the oil that is now pumping into the head!!!

On Saturday after fixing my cheap junky compression tester (purchased a Lang glow plug - has a built-in check valve) I ran a compression test and received about 440 psi on all 4 cylinders. Then performed a leak-down test and got crazy low leak values on all cylinders.

I'm thinking that running the head dry for 10 hours might have damaged the valve seals (or that the machine shop did something wrong during the rebuild)??? What else could it be?? I know I put the piston rings on right.

I did not take the exhaust off when I performed the leak test but I am willing to bet that I would see the exhaust ports wet with oil.

Just wanted to check with the group before making the call to the machine shop in case I missed something.

Thank you
Joe
 
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