Iseki TS1610F - Oil gushing from breather cap

larso1 · Nov 9, 2002

Howdy all you tractor nuts,
I just recently purchased this tractor, my first, for a real good price. Guess I know why now. Ha!

Anyway, need your help in diagnosing this problem. The motor starts real easy and runs well. No smoke after short warm-up. I run the tractor for about 5-minutes and oil starts to run out the breather cap on top of the valve cover in copious amounts, not just spitting out, but sort of gushing out. I've gotten a lot of conflicting advice from well-meaning friends on what could be the problem. Blow-by comes up alot in conversation. But others say a diesel wouldn't start easily if there was that much blowby, or a blown head gasket, or a cracked head.

So, I just performed a leak-down test on both cylinders and checked oil pressure with a new mechanical pressure gage.

Results: 22% leakage through front cylinder, 35% through rear cylinder. Oil pressure is 62-psi which I understand is pretty good.

I'm told by the guy who lent me the tester that 22% is good, but 35% could be causing me the problems. He thinks maybe it could have been overheated by the previous owner and that the rings on the rear piston could have lost their tension, or could be a broken ring. He said he's surprised there's no crankcase breather on these, and that might have eliminated the problem. It just seems like oil to the valve train isn't getting back to the crankcase fast enough. The only path for the oil to get back to the sump from the head is down the four push-rod tunnels. So, I ran it without the valve cover and could see that the oil wasn't returning very fast, but it didn't appear that it was being pushed back from the tunnel entry either.

So, that's where I'm at now. Guess my next step is to remove the head and check for a broken ring, cylinder wear, head gasket, etc. Interesting problem, but I'm up for it. Anyone have any other thoughts before I start? And, thanks in advance,

Bill in CO

Bird · Nov 9, 2002

Bill, sounds to me like you've covered the topic pretty well. I'm certainly no mechanic, but would speculate that some return holes (or tunnels) are stopped up. I've never needed to "flush" a diesel engine, but I think before I did a lot of disassembly, I'd be tempted to drain the oil, put in the appropriate (or just a little more) quantity of about a 3 to1 mix of diesel and motor oil, start the engine at idle, only let it run10 or 15 seconds, drain the crankcase again, replace the oil filter, and fill it up with fresh oil.

Now before you do that, let's see what some of the guys who know more about diesel mechanics than I do think of the idea.

jinman · Nov 9, 2002

I agree with Bird's advice completely. I'm also not a diesel mechanic, but as I read your post (prior to reading Bird's reply) I was wondering if someone may have used non-detergent oil in the tractor anc caused sludge to build up in the passages for oil. Surely, you could see oil bubbling back into the valve cover if you were getting that much blow-by. Do you think someone might have had the head off before and got the passages obstructed with gasket material or sealant. ...you just never know. Good luck. I'd give Bird's suggestion a whirl before tearing it down.

larso1 · Nov 9, 2002

Thanks for the replys Bird and Jinman,
Yes, it has been suggested to me by someone that something may be plugged up near the bottom of the block, maybe around the lifter area. And that oil sludge build-up may have occurred from lack of use over a period of time. I drained the oil and squirted about a can of Berrymans Chemtool down the pushrods, but I couldn't get enough flow with the spray can to make it back up; it just went on through. I also changed oil and am using 15W-40 Rotella T. It took a long time to get the 3-qts. down the pushrod tunnels, but I've been told that these 2-cylinder Iseki's take oil real slow..so that may not be associated with my problem. A guy at work suggested the kerosene / oil mixture too. But the guy who let me use the leak down tester, who also owns an auto repair shop, said he's never been able to clean up sludge in a motor just by running diesel or kerosene through it. (I wonder if he's tried?)He said if it's a sludge buildup, I would need to get in there and clean it mechanically with a brush or ? He also said that it could very well be that problem. As for the head being off previously, it sure could have. There could be sealant in there plugging things up, hadn't thought about that. One drawback with these 4x4's is that the front drive shaft prevents you from removing the oil pan without removing the drive shaft. Very inconvenient. I still need to get manuals so I can proceed without screwing up something.

Bill

jinman · Nov 10, 2002

Bill, I don't know anything better than Berryman's Chemtool for cleaning sludge. If that didn't do it, I'd be looking for something other than sludge as the problem. I also thought about blockage that would cause more oil than normal to be supplied to the valve train. If the flow was more than the designed return.... I know it's "way out there" to suggest, but your problem doesn't seem "normal." It's starting to sound like a tear-down is necessary. Maybe if you can get the manuals they will shed some light on your problem. Hopefully someone with some real Iseki experience will read and respond to your post.

em14 · Nov 10, 2002

I may have missed something, but, did you find any sludge in the head or on the valve cover when you had the cover off? ... Or did you find evidence that there was something there and it had been cleaned up? I would be very leery about thinning the oil and running the engine at all ... ever seen rods after they were run without the correct lubrication ... It has been my experience in rebuilding engines that sludge must be removed mechanically … Even after soaking in mineral sprits or parts cleaner, I had to scrub the sludge off with various devices such as screwdrivers, putty knifes, bore brushes and rags etc. If this engine is not allowing oil to return to the crankcase I wonder what else is going on ... this is a classical no oil change result ... but, before I would tear it down, I would certainly talk to an equipment dealer who handles Iseki equipment and see what, if anything, is unique to these Iseki engines and the oil problem ... I have a feeling you are going to be tearing this baby down and heading for a "hot tanking" at your local machine shop ... I presume that you can get parts and gasket sets ... Good Luck

larso1 · Nov 10, 2002

Thanks for the continuing replies, guys,

When I removed the valve cover, there was no evidence of any sludge. Just a rough, oily cast iron surface like you'd expect. I too thought about too much oil getting up to the head. The only oil feed is an external 1/8" steel tube running from the block up to the head. I thought, maybe it was possible that a pressed in restrictor at the pump discharge could have worked loose or something. I've read on another forum where some models of Shibaura had a pressed in fitting on the end of the cam shaft that sometimes worked loose and fell into the sump. Result was oil pressure less than 10 psi. But they didn't have the problem I'm experiencing. I wonder if I'm missing some breather line that relieves the crankcase. Can't find one, and I've looked al over the block for it. But how do these operate correctly without one? I mean, if the oil has to return down the same path that crankcase pressure from the inevitable blowby has to releave through.... well, something just doesn't add up for me. Thanks again for the responses.

Bill in CO

DK35vince · Nov 10, 2002

If there is excess crank case presure,usually it would push the oil out the dip stick tube and not the breather on the valve cover.

normde2001 · Nov 10, 2002

Bill, if you do a search on "Iseki tractors" you will find that a lot of the grey market/Yanmar dealers handle them. Maybe you can order manuals to assist in troubleshooting. Also, if your oil fill/ dipstick screws down maybe you can leave it loose and see if oil shoots out there. That will tell you if your crankcase is pressurized. I suspect there is a crankcase vent tube somewhere.