I Need A Diesel Mechanic

Eric Patterson

Eric Patterson

Moderator
Staff member
My 1964 MF 135 diesel starting using oil heavily and putting out blue smoke recently. It is using at least a quart of oil per tank of diesel, maybe more. It went from not using any oil to using a lot all at once. I do not believe the tractor has overheated, oil pressure is 40+ psi, compression checked out good, and there is no blow-by when you remove the oil cap. The air filter is clean and she is breathing easy. The hour gauge was broken when I got the tractor so I have no idea how many hours it has nor its maintenance history. I've put about 5 to 6 hundred hours on it since I bought it in 2012.

I took it to a mechanic I trust and he thinks it needs a rebuild. He says for $2000 he can do a partial rebuild (replace pistons), but would prefer to do a total overhaul (valves, re-machine head, and crankshaft if warranted) at a cost of $4500.

Other than the blue smoke and oil consumption this is a good tractor. Since purchasing it I've replaced/rebuilt a lot of the components (electrical, hydraulics, starter, steering, radiator, generator, tires, spindles, etc.) and done the routine maintenance. I can't stand unplanned downtime and keep my equipment well maintained.

With all that said is there any possible cause for the oil consumption other than bad piston oil rings? I'd hate to pay for a rebuild when the cause is something cheaper. A scrap yard will give me $1200 for the tractor. I'm having a hard time justifying the repair costs and am considering walking away from it but sure hate to lose the capability. We use the tractor a lot at the hunting property but with two sons in college and my wife in grad school now is not the time to dump money into a hobby tractor.

Not sure what to do...

Eric
 
Coworker down the hall who grew up farming and still has the family farm says its most likely a stuck ring.
Said you can try putting Sea-Foam or some other lubricant into the cylinders and letting is sit for a while, recommended googling "stuck ring in diesel tractor, lots of info out there.

He also said that this size and age tractor is pretty popular and is worth much more than the scrap value. He's seen them go for $4-6K down here.
 
I will say it?s a stuck ring also. For 2k what is he going to replace? Just the rings? If he is going to do that he is going to have to pull the head so you will need a new head gasket too. While he is there might want to see how much more for doing the rod bearings being you will have them out. Very simple job to do. Just a little time consuming
 
I too thought a stuck piston ring was the likely culprit. I also wonder if oil could be running in from a poorly sealed valve. It's a Perkins AD3.152 diesel. I was under the impression that to replace the pistons one has to drop the oil pan and get them out from below. But I'm not real sure on that. The more I think about it the more I'm opposed to a total overhaul. Compression is too good for that.

Also, as Carl suggested I googled "stuck ring in diesel tractor". I read where operating w/o a thermostat can cause rings to stick. Guess what, my tractor doesn't have a thermostat. Didn't have it when I bought it. It has always run on the cool side unless working the snot out of it. Hmmm.......

Eric
 
Eric,

They are a good tractor. Without knowing your financial situation I would say it is worth repairing. You may want to look at doing the rings and pistons. Your mechanic will know more once he tears the engine down.

While it is a little apples to oranges my uncle is having a 4020 rebuilt my grandfather bought in 1968. The tractor was used a lot, had the oil changed regularly. When it came to rebuilding the engine the crank looked great and was not replaced. Maybe yours is too. When I spoke to him last spring he said he had $9000 into it so far. My grandfather bought the tractor new for that.

Tom
 
Tom

Those JD 4020s are commanding top dollar these days from what I hear given their reputation for durability and the cost of a new tractor of similar ability. At nearly 10,000 lbs and 100 hp that is a workhorse of a tractor. His repair is less than 1/6th the cost of a new tractor.

Eric
 
Before you go too far with thinking about tearing it down I would take an oil sample to see what things are looking like. If you have a Caterpillar dealer close by you can buy a sample bottle there and they will test it there.

You mention you're running without a thermostat. I'm guessing you will find some fuel dilution of the oil. This can cause oil consumption and blue smoke from the oil being thinned down with fuel. Diesel engines need to be worked and ran at the proper operating temps. If you see a large amount of iron most likely you have broken/stuck rings, aluminum generally is from piston scuffing, tin comes from your rod and main bearings. The guys in the oil lab or service department at the Cat dealer can help you decipher your oil test results. A sample can tell you a lot about the health of your machine.

If you are seeing fuel dilution; change the oil and filter, get a thermostat in it, then go hook onto something that will load her down good and work the crap out of it.
 
Guy in my office echoed the same on the thermostat and running cold causing the problem:
Get a thermostat installed and have the oil checked before you pay for an overhaul.
 
Appreciate the input fellas. I think you are giving good advice that gives this thing another chance before sinking a lot of money into it.
 
I just spoke to the mechanic and discussed the tractor not having a thermostat. He wasn't aware and is going to install one and then I will work the engine hard to see if the blue smoke and oil slobber goes away. He isn't real optimistic but agrees it is worth a try. Also, I was incorrect about the compression being "good". He said he got around 280 lbs psi on each cylinder and that it should be around 340. That information is what makes him think it's time to rebuild. He may be right.
 
We had an old diesel at the place I used to work, went through almost a quart per tank of fuel...we jokingly referred to this as the perpetual oil change. She ran for years like that, and we work it hard.

As far as your investment in the tractor, how long you want to keep it going for your own use? With what you have already done to it, I wouldn't want to start over, as anything you buy without going much much newer will have an equal number of things needing attention. Those hobby sized tractors keep their value well, and the average consumer of them doesn't want to deal with major repairs. My guess is between your potential usage and what you will sell it for it is a decent investment in allowing you to do your projects. The alternatives being:buying almost new (expensive), buying another older tractor (and putting an unknown amount of sweat equity into it) or renting as needed (which as lame as it sounds, can make sense depending on how often you need it and how much you want to invest upfront).

I love working on old iron, but don't like being stuck with broken equipment at inopportune times.

Chuck
 
You can check for the fuel dilution yourself without taking an oil sample by simply wiping the dip stick onto a piece of cardboard. The oil will stay still while the fuel will run and absorb into the cardboard.
 
280 psi compression on a 54 year old Perkins doesn't sound too horrible. You said it doesn't have much blow by when you take the oil cap off. If the rings were bad enough to cause that amount of oil consumption I would expect to see a fair amount of blow by.

Are the compression readings pretty even across all the cylinders? Another thought, when were the valves last adjusted? If they're too loose it could affect your compression readings some, not dramatically but a bit. You have to get air in to compress it. Poorly seated valves could cause a loss of compression and worn valve guides with bad valve stem seals might be another place to look at concerning the oil consumption.

If we were a little closer together I'd dust off my wrenches and give you a hand. I kinda miss fixing tractors and heavy equipment some days.
 
Last edited:
Jim S said:
280 psi compression on a 54 year old Perkins doesn't sound too horrible. You said it doesn't have much blow by when you take the oil cap off. If the rings were bad enough to cause that amount of oil consumption I would expect to see a fair amount of blow by.

Are the compression readings pretty even across all the cylinders? Another thought, when were the valves last adjusted? If they're too loose it could affect your compression readings some, not dramatically but a bit. You have to get air in to compress it. Poorly seated valves could cause a loss of compression and worn valve guides with bad valve stem seals might be another place to look at concerning the oil consumption.

If we were a little closer together I'd dust off my wrenches and give you a hand. I kinda miss fixing tractors and heavy equipment some days.
Click to expand...

The mechanic said the cylinder's measured psi varied by a few pounds. I think high to low was about a 6-8 lb difference which he indicated wasn't an issue. He did said the tractor may not start if compression goes much lower (250?). Since owning the tractor I've not done any valve work. I too wondered about the valve seals but got the opinion on yesterdaystractors.com that even poor seals wouldn't lead to that much oil consumption unless oil wasn't getting back to the oil pan.

So my path ahead is to get a thermostat and work it hard with some SeaFoam or some other additive in the tank to help break down deposits that might be sticking the rings, assuming they are stuck and not worn. I'm not too confident that will work but want to try it before taking more costly actions. The step after than may be the to get the mechanic to look at the valves and eliminate that possibility before tearing her down.

Thanks Jim.
 
Eric,

I'd pull the plugs and get some seafoam directly in the cylinders. move them around a bit and let it soak.

you can crank a couple times with the plugs out to blow it out of there, or you can just put the plugs back in and fire it off.

agreed on the thermostat.

diesels are amazing machines. best of luck.
 
You must log in or register to reply here.
Back
Top