Kubota engine difficult to turn over when cold (not battery)

[dodge man]

The heat hurts the battery during the summer but it shows up in the winter.

 

[Slowpoke Slim]

It also depends on how *hot* in summer, and how *cold* in winter.

When we lived in Phoenix, the summer heat would cook wet cell batteries.

Up here, the winter kills wet cell batteries too.

I guess you could say I've experienced both ends of the spectrum.

 

[rv7charlie]

Now I am not an expert on diesel engines but I am constantly learning. This is another opportunity, I hope.

I have Cummins, Perkins, John Deere (when they still made their own) and a Kubota diesel engines. Question/issue is with the Kubota (49Hp).
The Cummins and the Perkins all have timed relays running the glow plugs. The John Deere and the Kubota are timed by the operator.

Now this issue has existed since I got the equipment back in 2014. Not something new. The OEM told me just use whatever GP time was needed to get it to turn over.
I have always thought the Kubota had a battery that was a bit undersized by the OEM but that is what they installed so that is what fits and is in use. The battery tests good and has a full charge when this happens. If I run the GP for the recommended 10 seconds cold weather, most of the time it barely turns over 1/2 to 1 turn then the starter chatters as if it does not have adequate battery power. If I then run the GP another 10 seconds it will normally crank and start. Occasionally it still barely turns over then chatters. After the third 10 seconds the engine turns over and starts fine. Yesterday this was repeated so that I eventually had 60 seconds on the GP. Yes I know that is a lot.
Other than burning out the GP what is the issue with excessive use?
Assuming it is not the battery and if it was why would it be fine after multiple attempts to turn over and multiple GP drains?
I know the heating from the GP warms the cylinder and makes the engine easier to start. Does the heating effect of the GP in any way change the resistance of the engine in the power required to turn it over? I almost now think that is what is going on. With 10 seconds the battery does not have the required CCA to turn it over but with the heated air somehow reduces the torque required to turn the engine over. Are the GP's possibly a problem? Just seems odd that the more time the GP are on the easier it is to crank the engine. I thought it made it easier to start not crank.

From a long-time electronics tech: I'd 2nd the motion to do voltage checks. Meter neg on the battery neg post (not connector; the post). Meter pos on the starter pos post (not the connector; the post). Should stay *at least* in the 9.5-10 Volt area, while the starter is energized.

Note that starters don't really chatter, unless there's some type of serious physical defect, like the mounting being so loose that the pinion teeth are slipping on the flywheel teeth. When you hear 'chatter', it's almost always either the starter contactor, or (depending on starter design) the actual starter *solenoid* (the small cylinder on the side of the starter). Chatter is caused by having just enough energy to pull in the contactor or solenoid, but not enough to turn the starter itself. When the starter winding comes into the circuit, voltage drops low enough that it's too low to keep the contactor or solenoid engaged, so it opens; voltage recovers, contactor or solenoid re-engages; process repeats. Low voltage can be caused by a weak battery, or high resistance anywhere in the current path (including in the joints between the copper wire and the terminal crimped on the end of the wire), or, and this is trickier to check, the contacts inside the starter contactor.

Back to voltage checks: Configured as above, monitor the voltage on the 'fat' post of the starter. If it drops lower than about 9.5V (should stay above 10V with a healthy system), move the meter pos 'upstream' to the next connection point & test again. At the contactor, check both the output side and the input side posts. At some point, you should see the voltage stay up at near the no-load voltage of the battery (~12.5--12.8V). When you see the voltage change from sub-9.5V to near no-load voltage as you move upstream toward the battery, the problem is between those two points.

The fact that it starts normally on the 2nd or 3rd or 4th try (indicating an intermittent issue) *sounds* like bad internal contacts in the starter contactor. If the contacts have begun to burn and wear, repeated start attempts can knock off the built-up corrosion on the internal contacts, allowing them to make adequate contact after numerous tries.

If, during your troubleshooting, the meter pos makes it all the way to the battery pos post (not the terminal; the post) and you still see the voltage drop to under 9.5V with the starter engaged, you've got a bad battery.

Quick & dirty check:
Grab a set of high current jump starting cables (at least 6 gauge wire; preferably 4 gauge or bigger). Connect neg to bat neg and to the starter's case bolt. Connect pos to battery pos & have the other pos ready at the starter. Do your normal glowplug sequence, then jump from battery positive direct to the starter 'fat' post (shield your eyes to protect against sparks). If it starts normally, you've got a high resistance issue somewhere in the current path.

Or I could be all wet..... ;-)

 

[panamaguy]

Strange, the only times that a battery has died on
me is in the winter they always work fine in the
summer but winter its a different story

willy

Same here from when I lived in Canada never a dead battery in the summer 30/40 below and they stop cranking as good. Now here in panama the heat cooks the battery so I usually open the hood when I get home to help cool the engine compartment

 

[JRH02]

My 'ol Kubota B7100 has always been Hard to start. Even when shut down for 15 minutes I have to run the low plugs for 15 sec. Even with a fresh battery it was cold blooded. I've replaced the cables with heavier ones. I added a 2nd ground point. Nothing helped.

One day I was doing something and had the hood lifted while starting it and saw a wisp of smoke above the starter. Solenoid? I doubted the starter itself- cranking time wasn't that long. Anyway, that was it, I'm done screwing around. I was surprised to find a new replacement on Amazon for ~$80 (free shipping ). Replacement was no big deal.

When I cranked it, it almost startled me. It fired off immediately. Man that engine spins when cranking now. All those years screwing around and it was an $80 fix.

 

[lpakiz]

rv7charlie,
Another quick VOM test is to hook the positive lead to the positive battery post and the negative to the copper starter motor post. Not the solenoid--the motor post.
The meter will read zero or very near, as there is no potential for current flow.
Now introduce the load (hit the starter) while you watch the meter. Whatever the meter reads, you can subtract THAT number from 12.6 volts (MOL) and the result is what is actually arriving at the starter motor post.
This will not indicate whether or not the battery is producing or delivering an adequate amount of current. It only indicates the condition (efficiency?) of the circuit.
And you can move one or both meter attaching points upstream or downstream, to measure voltage drop in whatever section of ANY circuit you wish to test.

 

[panamaguy]

My 'ol Kubota B7100 has always been Hard to start. Even when shut down for 15 minutes I have to run the low plugs for 15 sec. Even with a fresh battery it was cold blooded. I've replaced the cables with heavier ones. I added a 2nd ground point. Nothing helped.

One day I was doing something and had the hood lifted while starting it and saw a wisp of smoke above the starter. Solenoid? I doubted the starter itself- cranking time wasn't that long. Anyway, that was it, I'm done screwing around. I was surprised to find a new replacement on Amazon for ~$80 (free shipping ). Replacement was no big deal.

When I cranked it, it almost startled me. It fired off immediately. Man that engine spins when cranking now. All those years screwing around and it was an $80 fix.

I live in Panama and my B7100 is the same way. Even here were it is warm glow plugs needed but it has always started. My biggest problem is the steering box has piled up 2 times. I think the FEL might be putting to much stress on it. Might see if I can find a box out of a old Datsun, Toyota and replace the stock box

 

[twowoode]

A couple of things could be going on. I have the same problem with my little Massey when it’s cold. When the engine is really cold, which includes the oil, it is much harder to turn over. We used to use heat lamps under our cars in the winter so we could get them to start in the morning. The other issue is if your battery is not fully charged it can freeze, the lower the voltage the easier it freezes. Those saying they have an optima battery and it works fine is because an arm type battery works better in cold weather.

 

[coobie]

Whatever. I actually 'unlocked you comment to read you reply. Probably shouldn't have. Being as 'Battery Smart' as you are, I'm sure you know that cold don't kill a flooded cell jar, heat does.

Keep on trolling, it's always interesting.,..

States the LEAD TROLL.

 

[coobie]

One can read that all things are "good" and on another forum all things are "bad" on the internet. Lots of experts abound on all subjects. Sometimes it's entertaining.

For my own personal experience with Optima batteries, I've never had one fail. Started buying them 20-odd years ago, and every time, they've worked fine. I put a blue top "dual purpose" marine/rv battery (blue top, light grey body) in my '74 Dodge Power Wagon that was still going strong 10 years later when I sold the truck in the fall of 2011. It always had enough juice to start up that 11:1 compression 440 big block.

I put a red top Optima in wife's Toyota 4Runner the first winter we moved up here (2011). It's still there, and never had a single issue with it. The first time it got *cold* here, it killed the original OEM battery. 11 YEARS later, that red top Optima is still in her car, and still fine. Never needed a jump or failed to start. Ever. Last year was the first year her car got to sit in a heated garage, previous to that it was always parked in an unheated garage, or in the driveway.

In the first winter (2017) I had my new tractor, the first time it got *cold*, it killed the OEM wet cell Interstate brand battery dead as a door nail. I put in a red top Optima in December of '17. It's still fine. Never needed a jump start, or had an issue of any kind. Even now, it sits in an unheated steel building and will start on the first try even at -40F. Sometimes it will go a month without being started. Never failed to start, never needed a battery maintainer, battery heater or anything.

Last week I put a red top Optima in my '12 Ford truck, after the second time the Interstate AGM I bought in '17 was stone dead due to the cold. Truck sits outside all year 'round, brand new red top started it up like no big deal when the garbage Interstate battery whimpered and died. Both times the Interstate battery puked, I went out and fired up the tractor with the red top Optima in it, and drove it over to jump start the dead Interstate.

Your "facts" that "everybody knows" don't add up.

Nothing new there.

If those Optima batteries didn't work, I wouldn't buy them. They've never failed me in 20 years. The only ones I'm done with are Interstate. They'll never get another dime of my money. They refused to replace the AGM last winter when it died, because they had to charge it overnight (in a heated shop, naturally) before they would "test" it to see if it was "bad". Well, surprise and shucky-dang, it "passed" when it was warmed up from being inside all night. This year when it died again (seems the magic "cold" number is always about -30F or colder), I didn't even call them. I just went down to Napa and bought the Optima.

I have no use for a battery that won't work at -30F or below.

Great HONEST post..