Cold running diesel engine

[FarmerBlair]

I'm a relative newbie with diesel engines. In this cold weather, I
can't get my 841 diesel to get anywhere near operating
temperature. The temp gauge doesn't budge if I let it idle for
even 30 minutes. I used it for some light snow plowing using a
rear blade, and it did slightly warm up, but only maybe a 1/4
into the yellow zone on the gauge. I tried putting a sheet of
cardboard on the front of the radiator, and that barely had any
effect. This engine was completely rebuilt last year and has a
new thermostat (not sure of temp rating). I don't plan on doing
any heavy work with it this winter, but a little concerned about
running it cold. It also smokes quite a bit (blue smoke) when
cold. Just interested in any advice. Thanks!

 

[Bob]

Do you have the radiator almost completely covered?

 

[FarmerBlair]

Not completely covered. Maybe a couple 2-3 inches on the sides and bottom of the radiator are not covered.

 

[showcrop]

It is the general nature of diesels that they won't get above warm without a significant load. There have been many posts and threads on here about wet stacking and dilution of crankcase oil by fuel due to idling or extended low load running. Fan clutches on many modern vehicles don't often engage in cold weather, so it is very possible that your thermostat never opens, so the cardboard would have no effect. A possibility is that you have an over sized hole in your thermostat. It is a common practice to enlarge the little bypass hole in the thermostat to ensure a little constant flow. You could check with the PO about this, or remove the T'stat and check opening temp. you may find that it is lower than you want and one of a higher temp may be in order.

 

[oldtanker]

When I was driving bus we would start them up at 7:30 and idle em for 1/2 hour with the grill completely covered. When we took off on our routes they were still pretty cold. Would have to run about 10 miles before they would get up to operating temps. My 1206 IH does the same thing. Has to run the snow blower about 10 min before it's at operating temp. As stated just the nature of a diesel. If you are not going to work it you just are not going to get the temp up.

Rick

 

[john_Bud]

You can idle until the tank is empty and it won't heat the engine up much. You need to completely block the radiator and work it as hard as possible for as long as possible.

2 "bad" things happen to cold engines in the winter. First unburnt fuel washes the cylinders and leads to greater wear of the rings and cylinder and when it dilutes the oil,greater wear of the crank and bearings. The other issue is greater blow by puts a much larger amount of water into the oil and that can cause wear, rust and even freeze damage.

I don't run a diesel in the winter casually. I like to run them hard for 2-3 hours minimum. If there isn't that much work, well.... it might be best to wait or choose a different tool.

 

[oldtanker]

LOL it takes about 20 min to blow the snow here at PTO RPMs. Don't really have much chioce. Only have one tractor that will run the 8' blower. And I'm not inclined to buy that big of a gas tractor because I wouldn't want to feed that doing field work. It's also the only tractor I have that is big enough to feed round bales with. Sometimes you gott go with what you have. Now if I had a little more money to spend...I'd have a big gas tractor. Much easyer to start in the cold here in west Mn.

Rick

 

[Jerry/MT]

It"s hard to warm up a desel at low rpm conditions.
Spark ignition engines for all practical purpoes run at near the same peak gas temperture in the cylinder across the operating range because you change rpm by changing the airflow(via the throttle). The fuel ar ratio is nearly constant.

With a diesel, you have no air flow control. The fuel air ratio is the control variable and at idle the fuel air ratio is low so the peak gas temperatures are low. So to get a diesl to warm up you need to run it for a short while at idle and then gradually work it or increase the rpms to like 1200 rpm to let it warm. The best way to warm it up in cold eather is via a block heater.
Another way to getit to warm up faster is to put a piece of cardboard in fron to the radiator and run it at~ 1200 rpm.
Now this assumes the thermoststa is functioning properly. If the thermostat is stuck open it"s hard to get any engine to warm up.

 

[old]

Back when I drove truck the old girl I drove had a set of shutters a cross the radiator Those shutters would close up completely and when it was cold they would stay closed. It had a thermostat that control the opening and closing. Same with the new trucks now day it you watch most will have most of if not all of the radiators closed off on them. The reason is a diesel runs a whole lot cooler then a gas engine does so you might try closing off the radiator a bit more and maybe even go to a hotter thermostat say a 195 or so. Plus make it work light work little heat

 

[FarmerBlair]

Thanks for that information Jerry. I wasn't aware of that. I did have it running a bit faster than idle to warm up, but don't think I was as high as 1200 rpm. I'll seed if running it at higher rpms to prewarm helps.

 

[FarmerBlair]

Thanks for the advice JB. I thought running it would be better
than letting it sit, but maybe that's not the case if I'm not really
working it hard. I can use my gas 881 in most cases until
spring.

 

[FarmerBlair]

Thanks Old and Showcrop.....I'll check out the thermostat and see if getting a higher temp one is in order.

 

[old]

Good diesel are bad about running to cool and that in turn causes problems with condensation in the oil not getting steamed away

 

[David G]

My Ford 6610 has a thermostat in it, and will warm up to operating temperature after running about 10 minutes. I am now running it at 1500 rpm to avoid extended idling.