Diesel doesn't like the cold, frustrated

Two 100 HP diesels side by side, both with block heaters.... both older tractors....why does one start right up and the other takes much more "coaxing"

What can be done to an older diesel to start better in the cold weather? (aside from starting a fire under it or moving to Florida)
Might just start that fire and build it a bit bigger than required and then drive to town for parts.

A lot of it is compression, higher compression makes higher temperatures. The valve seats wear and make the valves sink lowering compression. I would do a compression test comparison between the two.

Obviously some engines start better than others. I'm unsure if we are comparing like diesels or diesels from different eras or even different manufacturers.

To make a diesel start we need good compression, good fuel delivery and good cranking speed. I say the one that doesn't start so well is lacking in one or more of those departments.

Make and model would help as some are just hard starters while others are getting weak or pumps/injectors aren't what they once were.

Casey in SD

Timing could play part of it too.

Using too much starting fluid can break the compression rings making it harder to start because of lower compression.

Do they both start equally well in the summer? Both plugged in the same amount of time? Both the same wattage element?

They should both start easily if they have an adequate wattage element and are out of the wind. A really cold blooded engine could need 6 hours of the block heater plugged in, in order to start.


Some tractors are naturally cold blooded. Allis 301 is a terrible engine to start in the cold. Playing with the timing apparently helps.
Also read on nnalert about a guy that had a 301 head sent away to be reworked. According to the guy telling the story, it would start no matter the temperature, had more torque, used less fuel. Whether it's the truth or not, I don't know, but that's the story.

Engine condition injection system condition . There is a lot that that makes the difference on how a diesel will start in cold . Compression , valve adjustment pump timing , pump cranking pressure , injector spray pattern and cracking pressure of the injector . How far the valves have sunk into there seats.
Will screw you up . Broken top compression rings will hurt you . AND the type of engine as some are just hard start cold while others are not as bad.

When you do get it started next time, pour a quart or two of gas in the diesel and get it mixed up good before you shut it off. It will start better in cold weather.

My old 7700 will start at 20 degrees with no heat time. Only needs a half hour plugged in at zero degrees if I need it to go as soon as possible.

My 5200 was terribly cold blooded, wouldn't start without either at 50 degrees. Needed plugged in hours in winter.

Then I got it a new starter, and a new positive cable.

Now it starts without help down to 35 degrees too, and very little help down to 20 degrees, and shorter plug in times.

Had to do with how fast the starter was spinning it, really really really made a difference in cold weather.

Paul

I swear tractors (old ones at least) have a personality. Some of them are just a bugger to get going and nothing you do will help. Growing up our 856 was a mess to get started in the cold. It got parked in November and fired back up after St. Patty's day.

After I read this the first time I started worrying about how much treatment was in the diesel backup generator. I went out and put some in the tank, hit the intake preheater for 15 seconds and it fired right up. I usually plug it in if we have a storm coming but with the next few days below zero I decided to just plug it in anyway. Seems everything gets brittle at those temps and I don't need it to decide not to start for the first time.

That intake heater makes a huge difference. I wonder if you could put a heat lamp on the intake?

Cranking speed, compression or just the difference from winter to summer blend.

My 1206 will start down to about 40 without help. After 40 to about 10 a little bump on the either assist button and it runs. 10 and colder it's gotta be plugged in. I feed hay this afternoon because we re supposed to be as cold as -60 with the wind chill Sun and Mon.

Rick

Are you sure your block heater is working? Went to plug the Unimog in the other day and the Kats heater didn't work. New one installed several years ago and might have been plugged in once. Defective already.

Well some of you guys are close as to why some will start cold and other will not. A gas motor has a spark to ignite the gas> With a disiel motor there is NO spark insteed they run on compressing the air and fuel up to a coprewsion ratio of 18 to 1 the COLDER the outside temp the harder it is to get cold fuel to ignite. When you plug in the heaters on motor you are keeping the motor warm and the cylinders are in the middle of all So plug it in Dale

My experience at a John Deere dealership. We'd have a line of brand new tractors parked in the lot. Same model and same model year. One would start right up at 40 degrees F with almost no smoke or skipping. The one next to it wouldn't even try without a block heater or ether. And when it DID start it would skip and smoke something awful. This became most prominent when we were selling 40 series ag tractors (i.e. 2040, 2940,) and C series crawlers (350C, 450C, etc.).

We had one customer who was trading in his 4020 he'd bought new in 1964 and a 350 crawler he'd bought new in 1967. Both his older machines would start down to 25 degrees F with no block heater or ether. He tried out a new 2940 and refused to buy because it smoked so bad when started cold. It did that at 50 degrees F!

So, Deere asked the same question you did. Things blamed included valve-seat recession too deep, charge pressure too low in injection pump, ignition/injection timing too retarded, piston standout too low, engine cranking speed too low, fuel delivery too low, etc. Deere finally concluded that the overall problem was sloppy engine assembly techniques with too wide "plus" and "minuses" with the machining tolerances. When the 50 series ag tractors came out, along with the D series crawlers - they started great. Most down to 25 degrees F.

I had the opportunity to take a brand new 350C all apart (that started poorly) next to a brand new 350D (that started great). The C had an engine built in Dubuque. The D had an engine built in Saran, France. The only mechanical difference we found between the two that made all the difference was the piston-top standout.

I'm talking new tractors. Obviously, when an old tractor is hard starting - you need to ascertain if it EVER started well.

(quoted from post at 23:12:21 01/04/14).

Then I got it a new starter, and a new positive cable.


Paul

Click to expand...

Condition of the negative cable is every bit as important as the positive cable.

my tractor is a gasser,but it was hard to start I put in a big new battery,new cables,ran the ground to one of the starter bolts,and got a rebuilt starter,now she works better good connections are important,and a bad starter wont spin fast enough lots of times it can be more than one thing thats fighting againgt you

a worn engine with used injectors will usually start better than one with new tips, excess fuel helps seal the cylinder raising the pressure on the compression stroke

Nobody mentioned oil viscosity yet.. I use straight #10 in the diesel tractor that I plan to use in winter. Block heater for a few hours and it fires up on the first turn of the starter. 2090 Case. Although back when I was still using the old Super 90 Perkins it fired up just as good with 10w-30 oil in the crank case as long as it had an hour or so with the block heater plugged in.