Cold Weather starting tips

[john_bud]

Hi,

I got a Private Message today on what can be done to help a hard to start diesel tractor. After writting the reply, I thought, "Hey, this is probably something everyone is interested in!". Here it is - I removed the person's ID as they PM'ed me and so that "private" part is being respected.

If there are any other tricks and tips on cold starting - please chime in! Winter affects us all!

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My kubota (B7800) is slow even when plugged in. I wonder if the hot plug is faulty? Any suggrstions?

I'm guessing you mean slow to start? In cold weather diesels are much harder to start. There are some simple things you can do that will help a lot.

1) Add diesel additive to the fuel to raise the cetane number. Add enough to raise it 5-6 points. The bottles will show the amounts. Cetane number is an indication of how easy the fuel is to ignite by compression. Higher is easier. Winter fuel blends are lower in cetane.

2) Run the glow plug (you called it a hot plug) for 3-4 cycles. It won't hurt it any, but it will drain the battery.

3) Speaking of batteries - battery power can be down to 25% of the summer cranking reserve due to the cold temps. To generate the temperatures to ignite diesel, the engines have to spin pretty fast. A weak battery doesn't spin the engine fast enough to start easily. Try adding a 10a charge to the battery for 15 min prior to attempting to start the engine.

4) DO NOT USE ETHER. (starting fluid) It is very very easy to misuse it and severely damage the pistons and even the connecting rods and crankshaft.

5) Add a block heater. There are 3 types. The best replaces a frost plug and has a heating coil directly in the coolang. The next best is spliced into the lower radiator hose. The least effective is magnetically attached to the bottom of the oil pan. Naturally, the ease of installation is opposite the effectiveness.

6) If you have electrical power (and don't want to mess with adding a block heater in the cold), you can use a hair drier aimed at the intake manifold for 15 min to heat it up some.

7) Change the engine oil to a lower viscosity synthetic. If you are in a bitterly cold area, 5w40 may be too thick. Heck, 5w30 may be too thick! Try a 0w20. Just remember to replace it with your normal summer oil in early spring.

Hope this helps,
jb


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Re-reading it, I notice that I missed the fact there is a plug in heater already. (Gotta get more coffee....)

If you suspect a bad block heater measure the resistance across the plug. A 600 W heater (common) is used the resistance measured will be about 24 ohms. 600w at 120V = 5 amps. 120v/5 amps = 24 ohms. (Right?)
A 1200 W heater will be 1/2 the resistance or 12 ohms. The cord will add a touch more to the total, but if you read an open or a couple hundred ohms, there is a problem.
jb

 

[4720 OWNER]

A magnetic portable electric oil pan heater could be a choice as well, plus can use it for so many other things. Will not heat up the whole engine but will heat the oil pan or anything else that is a ferrous metal. Plus very easy install. Have even gone so far as to plug one into a 'trouble' lite and then covered the whole kit and caboodle with a blanket to keep the heat in. Plus if have a remote switch easier to verify the heater is getting the juice.

 

[RonMar]

I think I would prefer to warm oil over lowering the viscosity too much. Warming the oil in the pan will help it flow better and speed the buildup of oilpressure on startup and save on internal wear. A battery blanket heater in conjuction with the other heaters and a charger would also enhance the battery performance in extreme cold.

You didn't mention how cold is cold... If we are just talking 30F, and it has started fine when this cold in the past, then perhaps the heater has failed as mentioned, or it is just time for a new battery. Remember that the factory battery size was suggested by an engineer, but the final decision on the actual battery used was most likely made by an accountant...

A good test on the battery was described by John, connect a battery charger to the battery a little while before starting. IF it starts normally with a charger applying power, then the battery capacity may no longer be acceptable at that lower temp. You might be able to extend the life of this battery by adding a maintenance trickle charger to the battery and plug it in whenever you park it, and it may work fine without it once the weather warms up, but this is usually an indication of an aged battery.

 

[RalphVa]

With newer tractors and even cars since 1983, running the glow plugs about 4 to 6 seconds seems enough. Then it's important to open the throttle some before starting. On my tractor, after I shut it down, I open the throttle up quite a bit. If it fires and seems rough, open the throttle enough to get it to near 1500 rpm.

I once started an old 1973 Benz with the old type glow plugs that had like a glow plug actually on the dash at -22 F. Glowed it for a full minute, gave it about half throttle, and it fired right up (this is with an engine heater). The fuel gelled 2 to 3 miles down the road (no additive). Let it sit about a minute. Restarted. Drove another 2 to 3 miles before it quit again. Again, let it sit about a minute. Restarted and stayed running then. Fuel filters on Benzes are mounted right up against the engine block. Good design.

Having no glow plug indicator on my 4010, I have to put the HST selector in gear, turn switch to "start" and hold it for a count of 4. Then run selector to "N". Usually starts immediately. Runs rough and needs more throttle if I haven't left the throttle open enough. Lots of white/blue smoke for about 5 seconds. Haven't tried letting it glow for maybe 6 to 8 seconds. Might cut down on the white/blue smoke and roughness of running when it starts.

If you have it die after a few minutes after it runs evenly, this probably means fuel has gelled on the fuel filter. A hair dryer then is probably needed directed towards the fuel bowl.

Ralph

 

[laurencen]

I have a Kioti CK20 and it starts prety good using the block heater, on the other hand at home I have a old Case 444, this is air cooled, this time of year -25C I simply plug a car warmer in under the hood and cover the front with a moving blanket, after 30 mins its good to go, I do this with the aeroplane also and that has no choke, works every time

 

[Wayne_H]

Remember, when your machine was new it probably started quite well when it was cold. If you need to cycle the GP's 3-4 times when its cold out, or you have to use your block heater when it is 20 degrees out, something is likely wrong. I chased a hard start problem down on my 88 7.3 Ford IDI for the past six months. It starts now in a few seconds when it's between 15 and 20 degrees out. What did it take? New battery, new battery cables, new GP controller, and 8 new OEM type GP's. Amazing how well it starts today, but after 20 years of ownership, it slowly got worse and worse, and since it was not a complete failure, it was hard to chase it down to one thing.

Wayne

 

[ctjstr]

What has always worked great on old kick start harleys is just plugging in a small electric heater and aim it right at the engine. Used to leave it there for about 10 minutes and it made a world of difference.

 

[RalphVa]

My experience with that old Benz was when it had around 160k miles on it.

Our present 1983 Benz has 205k miles. It still starts instantly after the required glow period (generally about 4 to 6 seconds in the winter).

As an aside, I have a 1972 Stihl chain saw. Was about ready to write it off but took it to the local repair place anyway. All they did was replace the spark plug. It starts first pull (with a squirt of starting fluid) and runs great.

Ralph

 

[George2615]

In a brief scan of the replies I see no one mentioned that you could have a bad glow plug. Just something else someone could check if they are having hard starting problems. I bring this up because it happened to me. I had hard starting problems a couple years ago. Tractor was in an unheated garage and cycling the plugs did not help. Mine is a 3 cylinder and I had 2 of 3 glow plugs were bad. You would have to isolate each plug and test with an ohm meter. A heated garage, low viscosity oil, block and or lower hose heater, fuel heater, fuel additives, and a good battery are the best ways to make quick starts possible but we all don't have these options.

 

[AlanB]

What throttle position do you guys use to start cold, my bobcat 743 with a 3 cylinder Kubota diesel in it says to have the throttle at halfway.

Sometimes I feel like I am flooding it.

My tractor and backhoe start with the throttle at idle just fine, but the bobcat does not seem to want too.

So, the questions would be,


What position for the throttle on cold starts

Can you "flood" a diesel.

Thanks

 

[George2615]

Alan,
For me, I start mine at closed throttle or lowest RPM then once it starts I raise the RPM to about 1200 and let it warm up. Some mfg. recommend starting at half throttle or more. I figure if my method of starting at idle speed starts my tractor thats what I use. I really wouldn't want to start a cold engine at half throttle. If your bobcat requires a higher RPM to start then that's what you use. Check your bobcats glow plugs and air filter. Maybe you have to cycle the plugs a couple times. Our bobcat at work starts at idle speed.

 

[RonMar]

I position my throttle at what would be about the 1200-1500 RPM running position, but I do not let it run at that initially. This is only to deliver a little more fuel at startup and as soon as the engine lights off, I immediatly ****** the throttle to the normal idle RPM(engine never exceeds normal idle RPM) till the engine warms up a bit.

This is just like a cold gasoline engine requiring choke(enrichened mixture) to start when cold.

Some cold weather hand crank experience on my diesel generator has shown me that if the fuel rack is not at the full throttle position when the compression lever is released, the engine is very difficult to start and will only partially fire and puff some smoke instead of making a meaningfull power stroke that increases engine RPM. The original versions of my engine actually had a small lever mechanism in the rack that allowed greater throttle travel for startup. As soon as the engine was running, the retarded throttle would activate the lever limiting the ammouunt of throttle that an overloaded engines governor could apply. This limited ammount of throttle was insufficient for reliable cold startup.

 

[RalphVa]

I open the throttle but don't let it go above about 1500 rpm. Usually, I haven't set it open enough to go to 1500 rpm and have to move it more open. If it starts rough, it needs more throttle. Just don't rev it hard. On the Benz I have no tach; so, I go my sound. It also has a hand-set fast idle on the dash that usually is enough, except on VERY cold days. The tractor's hand throttle isn't very precise as far as knowing how far to move it for it to start at 1000-1500 rpm. Even 1500 rpm is far slower than the fast idle setting on most gas engines, judging by the sound, certainly slower than fast idle setting on the old carb engines. On my VW with a tach, its fast idle generally is held to only about 1200 rpm; it has fuel injection.

Ralph

 

[Northland]

Those are good tips. I would allow suggest using a Mr. Funnel to insure no water enters the fuel line.

As a cold weather (-10 C to -30C), heavy snow area tractor owner I have learned how to get my Kubota warm asap.

I have the engine block heater on for 1 to 2 hours prior to starting the tractor. I also bought a Katz 200 watt magnetic heater ($25 at amazon) that I put on under the hydraulic fluid reservoir for 1 to 2 hours as well.

When the heaters have done their job I light the glow plug light to the count of 10 and start the tractor at 1500 RPM's. I start moving right away. I crank it to 2000 RMP's within about 10 minutes.

I find that the heaters allow me to use my FEL and rear blade immediately without any slowness that would be associated with ice-cold hydraulic fluid.

This method of warming up the tractor became that much more important
since my wife has banished the tractor from it's home beside her car in the garage. She tripped over the rear blade while unplugging her block heater one morning.

 

[KennK]

I have a JD 3320 diesel. I think I read somewhere that it doesn't really have glow plugs inside the cylinders, but instead has some kind of glow plug-like device in the intake manifold. Does anyone know if that is true?

When it is cold out all I do is turn the ignition key on, press the key in for about 10-12 seconds (the "glow plug" indicator lights up while pushing the key in), and then I start up the engine at the lowest throttle. It has always started up great. I should mention that in cold weather I put a trickle charger on the battery and it is stored inside my barn (not outside).

 

[SkunkWerX]

The case for this particular B7800 sounds like the classic "Low Battery in Cold Temps" syndrome.

Assuming the plug in heater is working (easy test for that) it should crank right over first or at most second attempt.

If you don't have a load tester then a quick and dirty test, before you try to start is to put a charger on it, one that has a gauge or needle you can watch, and observe it when you place it on charge.
If it's drawing heavy initially when placed on charge, then there is a likelyhood your battery is not up to snuff.

Swapping with a known good battery can also prove the trouble.

Whenver I have had this symptom, it's always been in need of new battery with enough CCAs to get the job done.

 

[john_bud]

This method of warming up the tractor became that much more important
since my wife has banished the tractor from it's home beside her car in the garage. She tripped over the rear blade while unplugging her block heater one morning.

That's just totally unfair! Unless the tractor stuck the rear blade out on purpose, or unless it laughed at her. Besides, just how do you think the tractor feels being put out because it's back side is too big?

jb

 

[wolc123]

Certainly that guy has a bad block heater. Any tractor with a properly functioning block heater should start as good or better in mid winter than it does in mid summer after being plugged in for an hour or more. On my JD, I dont even use the preheat, if it has been plugged in, no matter how cold it is. A properly functioning block heater is the best friend your diesel engine can have in cold climates.

 

[Z-Michigan]

I have a JD 3320 diesel. I think I read somewhere that it doesn't really have glow plugs inside the cylinders, but instead has some kind of glow plug-like device in the intake manifold. Does anyone know if that is true?

When it is cold out all I do is turn the ignition key on, press the key in for about 10-12 seconds (the "glow plug" indicator lights up while pushing the key in), and then I start up the engine at the lowest throttle. It has always started up great. I should mention that in cold weather I put a trickle charger on the battery and it is stored inside my barn (not outside).

Yes, that's quite possibly true. I have a JD 5105 and it has a manifold heater instead of glowplugs - basically a heating element in the intake manifold so intake air is heated, making things start easier. That way no glowplug inside the combustion chamber to fail. Our Dodge with a Cummins turbodiesel has the same thing. Works fine in both. I find the JD starts up in cold weather just fine with 5-10 seconds of manifold heater use (the Dodge has a sensor that regulates the manifold heater use, and it often seems to run as long as 30 seconds in cold weather before the heater light goes out, indicating it's ready to start). The tractor is stored in an unheated barn with no other heaters. I did go to synthetic oil (Rotella-T 5w-40) and am using powerservice in the fuel. The engine runs fine but I do find it can take one to several minutes for the hydraulics to have any functionality in cold weather, and much longer still before they run at a speed I like. In my case putting a heater on the hydraulic reservoir would probably be more valuable than on the engine oil pan!

 

[Egon]

Glow plugs or intake heaters are dependant on the type of combustion chamber the engine has.