Bad news big repair

[24mph]

How about an engine block heater ? In winter it will prevent he rattling and shaking and big cloud of black smoke. Just don't leave it plugged in too long, maybe 30 min. in single degree temps.

 

[Black Dog 2]

Purchased my M135X in warmer months almost 3 years ago (April 2019). Never thought to see if the glow plugs worked. They actually won’t work if it’s over 41*.
Last winter, I realized the glow plugs weren’t working. Ohmed out wires, looked at wiring for mice damage, water damage, bad grounds, etc. Ohmed out wiring. Thats when I learned the glow plug system in larger kubotas is more complex than I thought. All 4 glow plugs passed electrical testing.
The glow plugs have 2 sensors one for air temp, one for water temp. The ignition switch is also part of the circuit. Then there are 2 relays and a fuse. All of this is controlled by the ECU. Last winter, I replaced
Key switch
water temp sensor
air temp sensor
both relays
fuse

Still no glow plugs. With nothing left to replace or test, I succumbed to a very reputable Kubota dealer. They basically did all the same things I did and replaced one of the new sensors I had already placed.
Still nothing. They called Kubotas double secret probation hotline and Kubota thinks it’s the ECU.

ECU price $6000
ECU Not returnable and no guarantee it will fix glow plugs.

So I’m out of answers. Any thoughts on other possible avenues to pursue?

I have a L6060 with 360 hours and no problems so far. I also have a Cub Cadet SS7360 36HP 4cyl diesel that the glow plugs never worked even after replacing all components related to the glow plus system. I installed a manually activated system from the battery to the plugs with a 40 amp fuse. I turn on the manual switch for 7 seconds and have not had a problem since and it starts in very cold weather within 3 cranks but usually on the first one.

 

[RickB]

to overcome the the ECU derating the motor because the sensors are derated the easiest way would be to find a used glow plug and plug it into the ECU while the glow plug that is actually in the motor is run off a manual switch, if you were really tricky you could figure out what the resistance of the sensor is and just wire in the a resistor so the computer thinks there is a glow plug there. me I would just find another glow plug and it in, actually I would just suck it up and pay for the ECU, or just keep running it the way it is, maybe put a block heater in it to help out on the cold days.

There's no real evidence that this tractor has ever derated.

 

[MossRoad]

Unless your absolutely sick over it not working properly (In the tune of $6k Sick...). $50 Katz Block Heater...... Problem solved.

He already said he does not have a place to plug it in.

 

[jacspath]

Don't forget that every time a piston cycles, it severly compresses the fuel/air mix which heats it a lot [converting energy from the starter into heat]. If your battery is in good enough shape it should crank enough rotations to do the same work as the glo plug. I no longer use a block heater. In sub zero temps I just crank it for about 10 sec. Let it warm the metal [from the heated fuel/air mix] for a few seconds and crank her again. It usually takes 3-4 such cycles and a cylinder catches and away we go. Once the engine is warm it takes a long time for it to cool enough [if I turn it off in the field for some reason] to have to run such cycles again. It will kick right over if I restart within 30 minutes.

 

[MossRoad]

 

[Syncro]

I had an l-35 with automatic glow plugs. They never worked right so I hard wired a spring loaded toggle switch and mounted it in an easy to reach location by the starter key. Being spring loaded I could never forget it in the "on" position. It was an easy fix and worked faithfully until I sold the tractor a few years ago. BTW that l-35 was one of the best Kubota tractors I have ever owned.

 

[MHarryE]

You have both a M135X and M126X. Same ECU. Do the glow plugs work okay on the M126X? I had a M135GX, complained about harsh shift and they changed everything including the ECM. It was blank, needed initial flash to match the tractor. Assumed the 2 Grand X models with the 6.1 liter engine had the same ECM until flashed. I am thinking of ways to exchange some components between the 2 as a way to troubleshoot.

 

[northcreek2624]

Why not a block heater ?

 

[shadowm77]

has it got a block heater had an old massey 165 it did not matter how cold it was plug it in for 15-30 min fired right it had no glow plugs

 

[joea99]

The ECU reads the air and water temp sensors and they are both part of the glow plug wiring circuit and it has been stated that if the relays are bypassed, the tractor derates itself.
So how do you bypass all that and “simply install a switch”?

So, don't bypass them. Leave them in place, just disconnect the "last inch" that puts power to the glow plugs. Probably just a "buss bar" connects them all together and one end goes to the "magic box".

Then connect your own power to the plugs, as others have said, heat and crank.

BTW, who "has stated" it de-rates itself? Kubota or is that an "urban legend"?

 

[Laser Man]

Purchased my M135X in warmer months almost 3 years ago (April 2019). Never thought to see if the glow plugs worked. They actually won’t work if it’s over 41*.
Last winter, I realized the glow plugs weren’t working. Ohmed out wires, looked at wiring for mice damage, water damage, bad grounds, etc. Ohmed out wiring. Thats when I learned the glow plug system in larger kubotas is more complex than I thought. All 4 glow plugs passed electrical testing.
The glow plugs have 2 sensors one for air temp, one for water temp. The ignition switch is also part of the circuit. Then there are 2 relays and a fuse. All of this is controlled by the ECU. Last winter, I replaced
Key switch
water temp sensor
air temp sensor
both relays
fuse

Still no glow plugs. With nothing left to replace or test, I succumbed to a very reputable Kubota dealer. They basically did all the same things I did and replaced one of the new sensors I had already placed.
Still nothing. They called Kubotas double secret probation hotline and Kubota thinks it’s the ECU.

ECU price $6000
ECU Not returnable and no guarantee it will fix glow plugs.

So I’m out of answers. Any thoughts on other possible avenues to pursue

How about a block heater

 

[jgoodma1]

I don’t think it’s that simple, but yes, the thought crossed my mind. They make timer switches too, so you can’t accidentally leave them on.
The sensors must stay in place. We tried to bypass the sensors and if you bypass them, the engine runs de-rated.

I'm no mechanic, but FYI, I had a little John Deere 670 and the ignition switch rotated both directions. I'd rotate the key to the left for 10 seconds or so to warm the glow plugs then rotate to the right to activate the starter motor. That system worked great. Seems that the suggestions being made about a simple switch to activate the glow plugs would work the same way.

 

[MossRoad]

Maybe his chain isn't sharpened correctly.

 

[prairiegirl]

Purchased my M135X in warmer months almost 3 years ago (April 2019). Never thought to see if the glow plugs worked. They actually won’t work if it’s over 41*.
Last winter, I realized the glow plugs weren’t working. Ohmed out wires, looked at wiring for mice damage, water damage, bad grounds, etc. Ohmed out wiring. Thats when I learned the glow plug system in larger kubotas is more complex than I thought. All 4 glow plugs passed electrical testing.
The glow plugs have 2 sensors one for air temp, one for water temp. The ignition switch is also part of the circuit. Then there are 2 relays and a fuse. All of this is controlled by the ECU. Last winter, I replaced
Key switch
water temp sensor
air temp sensor
both relays
fuse

Still no glow plugs. With nothing left to replace or test, I succumbed to a very reputable Kubota dealer. They basically did all the same things I did and replaced one of the new sensors I had already placed.
Still nothing. They called Kubotas double secret probation hotline and Kubota thinks it’s the ECU.

ECU price $6000
ECU Not returnable and no guarantee it will fix glow plugs.

So I’m out of answers. Any thoughts on other possible avenues to pursue?

Keep the $6000 and build a heated shed with it maybe.

 

[thorn]

My late dad was an electrical engineer and learned to fix radios while he in the Navy during WW2 as a radioman (Morse code and tube radios back then). He continued to fix ours, relatives and friends electronics. In later years he was having a hard time finding ICs, they would probably have a production run and stop. After a few years they were impossible to find. They also started surface soldering components so it took more time to de-solder and re-solder. I wonder if one might have a hard time finding some IC components on older ECUs.?

After reading this thread, I have noticed my 2008 JD5525 has been harder to start in colder weather the last couple of years, lots of smoke and runs rough for a minute. When It's really cold I plug it in and it starts like its in the 90sF like summer.

 

[Skystream]

It's a 3 year old tractor, insist on getting the Kubota service representative involved. They have discretionary funds available for out of warranty repairs.

 

[ptsg]

It's a 3 year old tractor, insist on getting the Kubota service representative involved. They have discretionary funds available for out of warranty repairs.

The M135X was produced between 2009 and 2014, accordingly to TractorData. Definitely not a 3 year old tractor.

 

[5030]

I believe he's hosed far as any coverage for a defective part.

 

[geneP]

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