Pumping oil

[Lem]

1300 hrs on 2 cyl Isuzu diesel. Raised the hood and fired the engine took the breather cap off and set the RPMs to 1500 and within 3 minutes there was oil jumping up out of the breather spout in the valve cover. Cut it off for 3 minutes and started it back and put my hand over the pipe and it began to build up pressure until I released my hand. Good amount of pressure. Starts great and runs like it always did. No smoke out of exhaust. What is it? No drain holes were found in the head. The oil seems to return down thru the holes that the pushrods work the valves with and back into the sump. Engine strong as it ever has been.

Three more guys were having the same problem out of the same engine I saw on the net.

 

[Ilikeurtractor]

It's called cylinder "blow-by" and is not unusual on diesel engines, especially older ones or ones with high hours on them. Usually there is a baffle plate in the valve cover which does a decent job of keeping heavier oil droplets from going out through the vent. Normally the pressure built up in the crankcase (which of course is connected to the space under the valve cover) is routed back into the intake where it is burned. On "good" engines, there is no to little blow-by that is detectable and it is an easy check of the general condition of the piston and cylinder sealing. I have a 2AB1 Isuzu which may be the same engine you have and the rings became stuck in the piston grooves with only 1200 hours of operation on them. It is likely just cleaning them would have fixed the issue but I ended up replacing them while I had it apart. I suspect this occurs in some engines because they are operated under low loads a lot which allows the combustion gases to condense easier and build up on the rings. Kind of like running a fire place too cool where creosote builds more quickly in the flue/exhaust pipe. A lot of older tractor engines don't have a thermostat which allows the engines to run cooler which also aids this especially under light loading. I also suspect this causes the white smoke you'll usually see out of these engines. The exhaust temp will fall below the point of water vapor condensation creating the white smoke.

It's not always easy to keep the engines loaded up on tractors, especially if you're just moving trailers and other things around which I find is the majority of my work. In fact, only garden tilling and the rare occasion of snow throwing for me causes any decent loading for significant time durations. Cutting grass would probably qualify but I use zero turns for that purpose.

 

[Lem]

I am tickled to death with this answer because all that you spoke of I am guilty too. A thread that I took to heart and supports common sense to me. I did lower the oil from a 15-40 to a 10w 30 and that did help quite a bit. Did not go by my book I got with the tractor. Las fall it was fine and this spring it was spitting oil. No snow and I had no use to start the tractor x cept I ignored my manual telling me to run the engine monthly at 1000 to 1500 RPMs for around 10 or 15 minutes. Question: Is there an additive that I could add to the oil or the diesel fuel that would help in maybe unsticking these rings. Could Marvel Mystery oil put in on top of the piston for a time do that?

I plan on running the tractor quite a bit now @ teens of hundreds of RPMs and after it does it once in the am on start up after that it will go and go without any blow by.

Thanks so much for your input and the best I have gotten and totally believe this is true. Will change all my habits.....Thanks Lem

 

[Ilikeurtractor]

I'm not sure if there are any additives that will effectively unstick rings but I'm sure there are some out there that claim they can. And I'm not certain sticking rings are the root cause of your problems, I've just seen it happen on mine. In my case the engine just would not start one day due to loss of compression. I did have the valves redone too while I had it apart and the rings were definitely stuck. The combination of two cured the problem.

I was always curious why the hour meters roll at 1000 hours on most of these smaller, older tractors. Almost as if the manufacturer only planned on them lasting for about 1000 hours which is highly disappointing especially for a diesel engine. I do know that when I had a Mitsubishi KE70 engine bored and honed out the guy who did the work, who is also the owner of the machine shop and a good friend of mine, stated the block seemed unusually soft compare to what he was used to. The honing machine took a lot of material out quickly and he was surprised at that. So if the cast iron used in these blocks is prone to high wear this might explain the relatively short life of the cylinders and ring sealing. My friend recommended keeping up on the oil changes to help maximize run time on these engines. Installing sleeves made of a "better" cast iron may also help this issue.

 

[Lem]

This thing that I have happened almost over night. Last fall I did bush hogging and tilling of my too gardens and everything was fine until this spring I done some tilling and I was tracking myself as I backed up on solid ground so I headed to the house and tracked all the way of approximately 250'. Watched the light to make sure it did not come on so what happened happened over the winter months. I think letting them sit for a few winter months is not good for these small engines. The book says to change oil and put in 10 wt. when the temp drops below 32* and 20 or 10w30 in temps above 32*. and 30W above 70* which I have never done. I have new 10W30 in there now and my problems have gotten better...........Yesterday I pulled it up to the basement and locked it in on 1300 rpms and raised the hood and took the cap off the valve cover and in about 7 minutes I could see a little oil forming on the template under the valve cover and that took about 7 min's. When it got to where it was about to maybe jump out I cut the tractor off and within 5 minutes started it back and from there on it stayed dry all the rest of the time that I ran it and after the oil got heated up. My problem was not going by the book that Isuzu made for the tractor and leaving the 15W40 weight oil that was black as coal and thick as could be although it had only around 20 hours but had been in there for over a year. That oil shouldn't have been in there to start with. I can actually say the tractor seems to start better by turning over easier and is more limber and ready to go by what I did going to a lighter oil.

I saw something on Tractor By Net a month ago about oils, their weights and a page of a very interesting read and have not been able to find it since that time.


Thanks for your information and your help.

 

[Lem]

Think the 15W40 had a lot to do with my problem. I changed oil and filter to 10w30 like my manual says and helped it noticeably and when that got colored I changed both oil and filter and added Mystery Oil to the oil and diesel along with some Seafoam. I would let it warm up after I put that in there and watch under the hood and with the breather off looking down into the baffle and when it startred to form oil on top of the baffle I would shut it down for a couple minutes and upon start up it was good for the rest of the day with no pumping oil on the ground. Did that a couple times and the third time I saw no oil come into the baffle the next time or the time after so now I start it and warm it up for 10 minutes and all the bad stuff has gone away and no oil forms up there to be pushed out and to run down the side of the engine.. The lighter oil felt like it gave me quite a bit of more pep. Told you it had 1300 hrs but has only 1000 hrs. Thanks for listening. Got some 5W 40 Synthetic to go for the next round. The 2aa1 is a light diesel engine and requires lighter oil than a bulldozer ha ha. Thanks for your time spent with me. All is fine now. Takes a few hours for the oil to get to the point with come color to where I can check it on the dip stick.

 

[Lem]

My 2aa1 is close to 100% no as I can get it. No pressure buildup in the valve cover now when I put the palm of my hand over the vent hole in the valve cover. Before about 3 or 4 seconds and remove my hand and poof, you could hear the air blow out. None now and appreciate the help from you fine guys expecially llikeyourtractor. He helped me a lot. Runs, starts good and lighter gave it more spunk also.

 

[Ilikeurtractor]

Your welcome. It's nice to see people follow-up with their results instead of just "data mining" to fix their problem and never hearing from them again. I think it's great when people can reciprocate their knowledge to help someone else; either here or someplace else. Glad to hear it's working better for you!

 

[Lem]

Appreciated greately and may God Bless You

 

[loopman]

Thanks for posting about this!

I have a TE4270 (Iseki E3AE1 engine) which has been going great, then it hit 1200 hours and I got the same symptoms as you - blowby coming out breather and throwing oil all over the place after about 5 minutes of running. Changed oil and filter but no improvement. Starts easily, runs great with no smoke, just the oil blown out breather.

Did a compression test and cylinders were 410, 420, 440, manual says overhaul not required until less than 370psi. Didn't have equipment to do a leak-down test but thinking the sudden onset of the problem may be due to a broken or stuck ring?

Will see if I can get hold of this "Mystery Oil" and "Seafoam" you mention - fingers crossed that it helps me out too!