M7040 SUHD - Glow plugs

[SBLGFD]

Thanks up front to all who may respond

Recently bought a 2012 M7040 SUHD and am wondering if it has glow plugs.

The owners manual references them and I can see the glow plug indicator light on the dash .

However I have never seen the light light up -30 degrees here yesterday and it did not light up?

Going through the online parts look up for that unit I can find no indicator that it has glow plugs in the parts list - I might just be missing them.

I do have a block heater on order and intend on using that primarily.

Suggestions?

Thanks

Chris

 

[DevilDog]

Hello , Oh your 7040 has glow plugs to be sure, on my 3540 when I turn key light comes on for a few seconds then light goes off I now turn key all the way to start, but I can also hear a click when glow plugs are activated, can you? I may just be indicate light is burned out or a loose connection which I suspect.
DevilDog

 

[SBLGFD]

Nope I cant hear anything when I turn the key.

 

[North Idaho Wolfman]

Sent you a link to download the WSM for your tractor, let us know if you need more help or info in tracking it down or clarification on anything in the manual.

 

[lugbolt]

Yes it's got glow plugs. They work automatically, or at least that's how they're supposed to work.

ECU detects coolant temperature from the coolant temp sensor which is located on the thermostat housing. If coolant temp is above (IIRC) 32 degrees F, glow plugs do not activate-only the grid heater (or what I call "the toaster"). Below about 32 degrees (again, IIRC), the glow plug lamp in the dash should come on for a set amount of time, again, based on coolant temp. If you started and run the tractor the evening before, and the temp overnight got down to, say 20 degrees, and then you get up at 0600 to use tractor again, the coolant temp may not have dropped below the threshold temp that would turn the glow plugs on. This was something that I didn't like about the M7040's (and many of the M40's for that matter). And about the ONLY thing I didn't like about them to be honest. They're good tractors, long as they're taken care of.

To diagnose glow plug system. Shut engine off. Set park brake. Remove key. Remove the wire connector from the coolant temp sensor. I think they're green in color, again, located on the thermostat housing at the front of the engine. Leave the connector disconnected from the sensor. Get back in/on the tractor, then turn the key to "on". Glow plug lamp should come on and stay on for about 15 seconds or so. Why? Because with the ECT (engine coolant temp) sensor disconnected, the ECU "thinks" that the engine is ice cold, and cycles the glow plugs on for a little bit. If the light doesn't come on, you have some work to do..wiring, ecu, etc. But I've never run into one that didn't work as designed, usually just simply wasn't cold enough.

You can test the glow plugs manually but they're kinda fun to get to. Refer to the WSM.

 

[jcummins]

Have M7040HD....do you have shuttle shift? If so....

I could not get my glow plug light to come on, and went to a lot of trouble trying to diagnose it. Come to find out, Kubota...at least on this model...has funky control of the glow plugs.

My tractor is in insulated barn, and here, the inside of that barn doesn't get near as cold as the outside. But when below freezing, my tractor would start sluggishly. Was told, and found it is true, that with shuttle shift, if you put the tractor out of gear, but put the shuttle in forward position...turn the key all the way...you have the glow plugs on, there will be no light. Hold for few seconds, pull back to neutral on the shuttle...and the 'sluggishness' starting when cold is...gone. SO...I have always since, started by manual control of the glow plugs in that manner.

 

[Tx Jim]

Sent you a link to download the WSM for your tractor, let us know if you need more help or info in tracking it down or clarification on anything in the manual.

N I Wolfman
What vintage WSM is the link? I have a copy of WSM for vintage '06 but my M7040 is '11.
Thanks,Jim

 

[Dave_eng]

Have M7040HD....do you have shuttle shift? If so....

I could not get my glow plug light to come on, and went to a lot of trouble trying to diagnose it. Come to find out, Kubota...at least on this model...has funky control of the glow plugs.

My tractor is in insulated barn, and here, the inside of that barn doesn't get near as cold as the outside. But when below freezing, my tractor would start sluggishly. Was told, and found it is true, that with shuttle shift, if you put the tractor out of gear, but put the shuttle in forward position...turn the key all the way...you have the glow plugs on, there will be no light. Hold for few seconds, pull back to neutral on the shuttle...and the 'sluggishness' starting when cold is...gone. SO...I have always since, started by manual control of the glow plugs in that manner.

This is a previous post of mine along the same lines.

I own a 2012 M7040 with Cab and FEl
Dealer's mechanic gave me this trick to help starting in very cold weather.

In very cold weather, with the block heater plugged in, the glow plug sensor will lock out the glow plugs as it senses a warm engine.
However, starting, in these circumstances can be rough and worrisome.
The trick is to put the shuttle shift lever in forward and turn the key to the start position.
You will hear a relay click on. I count to 10, put the shuttle back into the neutral position and start the engine.

How this came up was I was at the dealer on a reasonably cold day and noticed the staff moving around a large number of tractors for snow removal. These are machines that could have been sitting for months. The mechanic said they used to have problems getting all machines started in spite of using the glow plugs as allowed by the tractors electronics until the service rep told them how to get another cycle out of the glow plugs which was the shuttle shift in forward and turning the key to start. The electronics wont give you a second round of glow plugs even if you wanted them. Without this trick, when you turn the key to on, if the tractor is cold enough to need the glow plugs, a symbol lights up on the dash and you just leave the key in the on position until the symbol goes out and then turn the key to start. If the tractor does not start you are screwed. I am certain the system re sets itself after a while but I don't know how long.
When using this trick, the dash symbol does not light up and all you hear is a relay click once when you hold the key in the start position.
I count to 10 holding the key in start to not overheat the glow plugs as this seems to be how long they stay on under the controller in the coldest conditions.
When you return the shuttle shift to neutral and turn the key to start there is no doubt that the glow plugs have heated up.
It makes an amazing difference.
I dont know which other models this applies to but from what I saw many newer models have some trick to effect this.

Dave M7040

 

[SBLGFD]

So it would appear that it was simply not cold enough - disconnect the coolant sensor and it seems to work fine.

Also tried the trick of putting the shifter in Neutral and the shuttle in foreword and cycling the key - I can hear a relay click - I will try to get a meter on the glow plug relay so I can confirm that's what I'm hearing but I would bet that what it is - good trick.

Thanks to all.

Chris

 

[North Idaho Wolfman]

N I Wolfman
What vintage WSM is the link? I have a copy of WSM for vintage '06 but my M7040 is '11.
Thanks,Jim

I'm not to sure, I know that's one model that's evolved a lot over the years.
I'll send you a link and you can compare.

 

[North Idaho Wolfman]

SBLGFD,
As it gets colder keep an eye on the Glow plug light, if it never comes on when it's cold, you could have a bad sensor since you confirmed that the rest of the system is working.

 

[Tx Jim]

NIWM
Thanks for the link. I inspected the WSM & it's dated 2006 same as the one I had downloaded.
Thanks again,Jim

 

[dmac]

Thanks for the help, now I can utilize the glow plugs at moderate temperature or as I need them