This sounds like an oil flow/pressure problem big time to me, why did the engine fail previously, low oil flow?
L3250 noisy valves more than a simple lash adjustment
- Thread starter J03bota
- Start date
This does sound like little/no oil is reaching the valve train. You need to measure the oil pressure vs. RPM for 4-5 points after the oil has reached operating temp. It needs to go up with RPM, flat pressure means you have a leak or bleed point.
First check the relief valve has not stuck open. Remove the valve assembly and look for galling between the piston and wall. Clean and polish and reassemble with a little grease on the components; then take the pressure vs. RPM measurements. Let us know results. Jeff
First check the relief valve has not stuck open. Remove the valve assembly and look for galling between the piston and wall. Clean and polish and reassemble with a little grease on the components; then take the pressure vs. RPM measurements. Let us know results. Jeff
I finally installed the sunpro mechanical oil pressure gauge last night. I used copper tubing and confirmed that there is oil sitting right at the gauge. not sure if the gauge is supposed to fill with oil as well? this one certainly did not.
Started the tractor ran it for a while getting about 50 to 55 lb of pressure and it does not vary as I change RPMs. Have no idea where the pressure relief valve is on my tractor?
I had the engine rebuilt because it was blowing oil.
Thank you.
Started the tractor ran it for a while getting about 50 to 55 lb of pressure and it does not vary as I change RPMs. Have no idea where the pressure relief valve is on my tractor?
I had the engine rebuilt because it was blowing oil.
Thank you.
rbargeron
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The relief valve is inside the oil filter support 070 (see pdf). Parts 230, 240, 250. 260 are the pipe fitting, spring, ball and valve seat. If your pressure reaches 55 psi but holds steady at higher rpm, the pump and relief are performing normally. There could still be a blockage of oil to the rocker shaft, loose guides or seats, bad seals, etc.
What does "blowing oil" mean exactly?
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Don't even know where to begin. Here is my original link that lead to the rebuild.
http://www.orangetractortalks.com/forums/showthread.php?t=27856&highlight=l3250
What about this idea:
Start the tractor with the head cover off and try to identify where the noise is coming from.
Possibly use my oil can and squirt some oil down the push rods onto the tappets, then on the rocker arm assembly, then on the valve seals area last.
If I do this should I expect a lot of splashing oil or a little??? Will I have a major mess to clean up or a little?? It might be worth it I should be able to find the noise pretty fast. Right??
Thank You
Joe
rbargeron
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Could be a good way to see something. It shouldn't be too huge a huge mess - I'd do it outside where it can drip off for a while afterward. I haven't run any Kubotas with the valve cover off - the top oil pipe aims the little streams at the rocker arms but some may overshoot and get on the exhaust manifold. It may smoke but shouldn't flare up.
To reduce the mess maybe try making a temporary dam by sticking an old valve cover gasket in place by itself. It's U-shaped so would dam up the oil a bit and guide it to the returns.
To reduce the mess maybe try making a temporary dam by sticking an old valve cover gasket in place by itself. It's U-shaped so would dam up the oil a bit and guide it to the returns.
rbargeron
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Joe, you've sure been through a slog with this engine.
The symptom that's been nagging me is the temporary quieting, followed by return of valve noise and skipping, power loss, smoking. Taken together with the heavy oil deposits on the middle exhaust valves I'm still thinking it has valve train problem - loose valve seats or guides, maybe even a crack. The seats could be just snug enough to stay put until the engine warms up - then start jumping.
Back when the seat surfaces were found not concentric, it was a sign something was not right with valve alignment in the head. The quieter running after adding oil is maybe a red herring - the engine cools off by adding oil, then gets into trouble when it warms up again. I'm thinking the head needs to come apart again and be checked carefully for problems.
North Idaho Wolfman
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Pull the cover and check / run it.
You should have a slow stream of oil washing around the rocker arms, there are nothing like an old V8 that will spit it everywhere.
The oil will just flow back down as the head has channels built into it that cause this to happen.
If you're not getting oil to the head or rocker arms, I woulds suspect blocked oil pipe between block and head or cam plug missing.
Take a video of it running with the cover off.
You should have a slow stream of oil washing around the rocker arms, there are nothing like an old V8 that will spit it everywhere.
The oil will just flow back down as the head has channels built into it that cause this to happen.
If you're not getting oil to the head or rocker arms, I woulds suspect blocked oil pipe between block and head or cam plug missing.
Take a video of it running with the cover off.
I would try replacing the John Deere break in oil, along with a new oil filter.
Shell Rotella T5 in 10W-30 or T6 in 5W-40, perhaps with half a quart of Mobil 1 Advanced Fuel Economy in 0W-30, to make it flow better when cold.
Shell Rotella T5 in 10W-30 or T6 in 5W-40, perhaps with half a quart of Mobil 1 Advanced Fuel Economy in 0W-30, to make it flow better when cold.
Note that the filter is Kubota HH164-32430, which translates to Fram 7328.
If you have room an XG16 is just over half an inch longer,
an XG8A is just over five inches long...
(Kubota is three inches long)
Same base, same bypass pressure...
If you have room an XG16 is just over half an inch longer,
an XG8A is just over five inches long...
(Kubota is three inches long)
Same base, same bypass pressure...
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This engine has solid lifters. Hot or cold oil, high or low oil pressure will have little effect on regular valve train noise if the clearances are correct. Valve train noise (significant noise) related to those issues is a hydraulic lifter phenomena. In a diesel I would be careful about getting carried away trying to reduce valve noise by tightening the clearances down. You're not playing with much clearance to begin with.
Does the noise seem to be concert with engine speed or apparently at "half engine speed". Valve noise, assuming from a single culprit will seem slower than the rpm. A quicker tempo noise (seeming to occur every revolution) is often related to the piston or connecting rod. That doesn't mean it is a "bad" noise. It might just be a little piston slap.
Speaking of piston slap. Do those pistons have an orientation mark? If so it means they likely either have recesses to clear valves or there is some pin offset. If a piston with an offset pin is installed wrong way around it will slap the cyl wall at TDC, make noise and cause vibration.
You did not mention checking/servicing the small end on the connecting rods. A pin bore that is too loose will make noise. Not usually vibrations though unless it was really hosed. It will also usually quiet down a little as the pin heats up and reduces the clearance. Were the large end bores of the rods checked for out of round, size and resized if needed? They're probably fairly close though or your oil pressure would suck.
Finally... are you sure it's making a really unusual noise? Diesels make a lot of noise.... I mean it could be a slight variation in the injector timing for one cyl or another and there's nothing you can do about that.
It could be a lot of things.
Does the noise seem to be concert with engine speed or apparently at "half engine speed". Valve noise, assuming from a single culprit will seem slower than the rpm. A quicker tempo noise (seeming to occur every revolution) is often related to the piston or connecting rod. That doesn't mean it is a "bad" noise. It might just be a little piston slap.
Speaking of piston slap. Do those pistons have an orientation mark? If so it means they likely either have recesses to clear valves or there is some pin offset. If a piston with an offset pin is installed wrong way around it will slap the cyl wall at TDC, make noise and cause vibration.
You did not mention checking/servicing the small end on the connecting rods. A pin bore that is too loose will make noise. Not usually vibrations though unless it was really hosed. It will also usually quiet down a little as the pin heats up and reduces the clearance. Were the large end bores of the rods checked for out of round, size and resized if needed? They're probably fairly close though or your oil pressure would suck.
Finally... are you sure it's making a really unusual noise? Diesels make a lot of noise.... I mean it could be a slight variation in the injector timing for one cyl or another and there's nothing you can do about that.
It could be a lot of things.
All parts mentioned are brand new
After the rebuild the engine is definitely quieter
It barely even smokes now after it warms up. Only seems to smoke if I push it to almost stall. Then I think the smoke smells like oil
it used to smoke all the time before the rebuild the noise sounds like lifters increases and decreases with RPMs. All my complaints might be close to normal for this tractor I just don't know and I do not want to make any mistakes this time around. Besides the pushrods I did not replace the tappets nor did I replace the rocker arm assembly
Everything else is brand new On the head.
Thank you
Yes, the pistons have a reservoir that likely concentrates fuel from the direct injectors. I made a point to install them according to the manual - all facing toward the injectors or fuel pump.
One point that I mentioned earlier that you might have missed: the very 1st time after I change the oil the engine runs quiet for that day. then the next day or whenever I start the tractor after 1 day of oil draining back down to the oil pan, the valve ticking-like sound comes back. That's why there has been much focus on the head and head parts. The head and brand new valve train was rebuilt by a very reputable machine shop. The ticking sound and overall engine noise is better than it was before the rebuild but its still there.
thank you again.
rbargeron
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A week ago in post #1 of this thread the valve noise and smoking were still there despite all the parts replaced. But in post #33 the engine is now sounding normal and smoking has nearly gone away?
When trying to identify the location of a noise, I find a piece of rubber gas line a great tool. Use it as a stethoscope. If you suspect any exhaust leak start with the ear end away from your ear a bit as there may be air, or fumes coming out an exhaust problem and you don't need to subject your ear to pressure from a leaking joint or cracked manifold.
I would try this with the valve cover removed moving from valve to valve.
To others who know this engine, is there a pcv valve or EGR valve that could be making nose?
Dave
I would try this with the valve cover removed moving from valve to valve.
To others who know this engine, is there a pcv valve or EGR valve that could be making nose?
Dave
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When you changed your oil, did it seem thin and smell of diesel? Was it over full? You say it quiets down the day you change the oil then gets noisier. I am wondering if one of the injectors is leaking fuel thinning down the oil. Another spot diesel can get in is a leaking shaft seal on injection pump or the fuel lift pump going bad. 30W oil is a little thin for older Diesel engines. Usually you use a 40W like 15-40W or 5-40W.
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I don't know if this engine has the plug at the block casting at the camshaft ends, (but it sure has the symptoms like the plug fell out of the engines that had them).
Ok, one thing I want to mention is to forget about your method of adjusting valve clearance. Use the EOIC method. I did not see if anyone had suggested it or if there was a fix yet, but I wanted to take the opportunity to discuss Kubota's method and the EOIC method. While Kubota's method isn't too terribly hard to figure out, the EOIC is MUCH simpler. EOIC stands for exhaust opening, intake closing. Meaning this: When the exhaust valve just begins to open, adjust that cylinder's intake valve(s). Then when the intake valve is almost closed, adjust that cylinder's intake valve(s). That method saves a lot of time and aggravation and is so easy that a cave man can do it. I do it this way on V8 stuff, specifically on the race cars, as it's MUCH quicker-and easier-than the TDC method.
On lawn equipment and some ATV stuff, you can't really set them via TDC because of the automatic decompression mechanism that holds the valve open slightly near TDC. On those, you have to rotate the engine about 10-20 degrees of crank rotation past TDC and check them. Or use EOIC which is what I do and it seems to confuse everyone whom I've tried to teach it to.