M7030 Blow-by (HELP)

[PoorPlowboy]

Depending on what you find it may be cheaper (and easier) to get a new short block and abandon the old block. If it is not too bad you can have it rebored and then move up to the next piston size. Either way you will be looking at a complete engine job.

This is by far the most affordable option, if it's possible.

 

[BXpanded]

Unfortunately, people tend toward the worst possible situation. There are several things that can cause blow-by that have nothing to do with a damaged block. Do a compression check and find the cylinder with the problem and work from there. When you have identified the problem you can explore your options to repair it. Until then, all the long distance guessing accompanied by the doom and gloom can be counter productive.

 

[PoorPlowboy]

Unfortunately, people tend toward the worst possible situation. There are several things that can cause blow-by that have nothing to do with a damaged block. Do a compression check and find the cylinder with the problem and work from there. When you have identified the problem you can explore your options to repair it. Until then, all the long distance guessing accompanied by the doom and gloom can be counter productive.

I understand your point, but what do you propose he do after he finds the cylinder causing the blowby? What else could it be other than a worn out or broken ring? If the ring broke, it scored the cylinder requiring a boring or resleeving.

 

[kuboman]

Unfortunately, people tend toward the worst possible situation. There are several things that can cause blow-by that have nothing to do with a damaged block. Do a compression check and find the cylinder with the problem and work from there. When you have identified the problem you can explore your options to repair it. Until then, all the long distance guessing accompanied by the doom and gloom can be counter productive.

You are correct, the first thing to do is find out the problem. Unfortunately with a parent bore engine there is never a real happy solution to repairing them. Blow-by is an indication of a fairly serious problem that usually requires expensive/extensive repairs.

 

[Sackett876]

I have had to the Kubota Dealer 2 times!! And another mech. 1 time,,,,both say compression is good...tractor smokes 0000, none no smoke,,,,no lose of power!!! One thinks that it is bad o-ring in injector pump, having said that this pump has less than 50 hours, over pass 3 years....Kubota Dealer is who told me that he thought it was rusted/pitted cylinder walls??? Just some more on the tractor...

 

[crazyal]

Unless you are in a big hurry to get it up and running again I would do a compression check and then pull the head. Once you know more about what's wrong then you can look into all repair options. It's not likely but you could find the head gasket blew and instead of leaking to a cooling water port it's leaking to an oil passage port.

 

[5030]

OK so I'm really getting educated here...I'm a fair "shadetree" mech., but the pros here are helping greatly, for example 5030 I read your posts from Feb-2006 in regards to m-series tractors...from what I gathered there the M-series can be re sleeved,,,?? where you wrote & I quote;

"BigCajun:

You can resleeve either type, it's just harder to pull the liners on a parent bore engine....you need either a screw type liner puller and a 3/4" drive impact wrench or a hydraulic liner puller. There is another way though. Run a weld bead vertically from the top of the liner to the bottom. It shrinks the liner away from the block wall and allows easy removal.

There is another type of diesel though not very common and that is a bored block and no liner. That's a throw away engine.

I'm going to do my 1085 this summer. It's a Perkins parent bore.

A wet linered engine has to have seals on the liners or what is called crevice seals to keep the coolant on the wet side of the liner and not on the combustion side. Parent bore/dry linered engines need no seals as the liners are a dry interference fit in the block itself."


Am I reading this correct???

Oddly enough, I had a Massey 1085 with a Perkins naturally aspirated 4 cylinder diesel that had a broken compression ring and it scored the liner. It was shrunk in or parent bore as well.

On wet linered engines, the liner sits on crevice seals and the deck height (top of the block) plus the stickout determines the liner height after the head is torqued down. The head pushes the liner on the crevice seals and excludes coolant from the crankcase. The headgasket seals the top of the liner against coolant and oil leakage into the combustion chamber.

With shrunk in liners, the liner is installed cold (as in dry ice cold) and dropped into the parent bore and set level with the deck before it has a chance to expand. They can be removed with a hydraulic puller (that any competent dealer has) or by running a weld bead (SMAW) vertically inside the liner, top to bottom, 180 degrees opposite. The weld shrinks the liner and it will actually become loose in the bore. That's how you pull 'em on a Perkins or an Oliver.

Never pulled a liner on a Kubota. Never had a problem with a Kubota engine. Mine have all been bulletproof.

Knock on wood.....lol

 

[5030]

.........A wet linered engine has to have seals on the liners or what is called crevice seals to keep the coolant on the wet side of the liner and not on the combustion side. Parent bore/dry linered engines need no seals as the liners are a dry interference fit in the block itself........

Additionally, the oil and coolant passages are in the block casting and have no physical contact with the liner at any time.

You have no need of running anti-cavitation additive (DCA4) and/or extended life antifreeze because there is no direct contact.

The only advantage in extended life in a parent bore engine relates to the radiator itself. The extended life resists solder bloom and Ph degradation.

 

[art]

I would wonder what the hours are and the type of running and jobs this tractor has done.

I've seen tractors that have glazed the cylinders from running cold. This will give you the trouble that you have.

 

[suzy]

Hey Art, could you define 'running cold' for us who are new to diesels? I have yet to start it up when it is very cold out. How long should the engine warm up in various temps. before moving? Is there a chart for this anywhere? Thanks!