Oil & Fuel Need to Warm Up a Diesel Engine?

hwp · Nov 5, 2002

The impression I get from reading a number of posts on various topics is that it is harmful to a diesel engine to use it before the engine is full warmed up. Is this really the case? This is my first diesel tractor but I have owned several diesel cars and never had a problem with driving them as soon as they were started. Most of those cars had well over 500k miles on them before I sold them and they were still running strong. There is no question that there is a better fuel burn, and therefore more power, at higher temperatures but these engines have to run to warm up so why not use them in the process? I notice that some jurisdictions now prohibit vehicles, particularly diesel powered busses and trucks, from being left idling for more than a few minutes. I have never seen any notation in an owner's manual that a diesel engine should be full warmed up before being used. So what is the basis of the widely held belief that diesel enignes must be fully armed up before they can be used?

cowboydoc · Nov 5, 2002

You will probably get alot of different responses to this. I do believe that you need to let a diesel warm-up for at least a few minutes if it is cold. If it is not cold then drive it right away. The reason is to let the oil warmup a little and get better flow. Plus things break very easily when the temps get down really low. If you let the tractor warmup a little this isn't as big of a problem either. Power steering, the brakes, engine, etc. all work better when the oil is warmer.

Can you probably get away without warming up? I would say yes here as well. I have never seen any actual studies saying one way or another so it's hard to say. On the old powerstrokes you didn't have any power until they were up to normal operating temp. I am just going by what has worked for many years for us.

On a side note if you plug them in then you can usually go about right away as the engine is already warmed up.

snowman · Nov 5, 2002

In the winter, I start it, pull it out of the garage, walk around and do my manually shoveling around the house and garage doors, then rev it up and go. Probably five minutes warm up at the most. Have never had a problem, but have only had it two years - about 210 hours now.

RobS · Nov 5, 2002

I think the key is keeping the stresses low until it is warmed up. As long as the lubricating oil is flowing, it won't hurt to putter around a bit while warming up. In fact, it will help some by warming the other fluids in the system /w3tcompact/icons/smile.gif

JohnMiller3 · Nov 5, 2002

...Most of those cars had well over 500k miles on them before I sold them and they were still running strong...

Howard... WOW!

Two questions:

How old are you? /w3tcompact/icons/wink.gif

& What the heck kind of cars did you have...? /w3tcompact/icons/blush.gif

As good as Toyota's and the Honda's are... they'd be hard pressed to go 500,000 miles...

"I just gots to know".... /w3tcompact/icons/smile.gif

Boondox · Nov 5, 2002

I wondered about this myself till one winter when the seal on my HST filter failed at startup on a minus 10 day. The leaking fluid was very thick at that temp -- almost like maple syrup -- so since then I've let it warm a bit more when brrrr-cold outside.

Pete

Soundguy · Nov 5, 2002

On the heavy equipment at our construction company, many of the units have large hydrostatic drives, and they have a hydraulic pressure bypass that you engauge in very low temps, to aid in starting ( Motor graders mainly ).

Soundguy

Mosey · Nov 5, 2002

I agree with RobS, go ahead and use it but don't work it hard until it's warmed up. I work for Cummins Engine (diesel engine manufacturer). I'm an electronic/software guy, so I'm not an expert on the mechanics, but when I first got my tractor I asked an engine designer, who is an expert (has a PhD in mechanical engineering), and he said they don't need to sit and idle to warm up and will warm up faster if you start using it, but don't lug it until it's warmed up. If the temp is 20-25, I plug in the engine heater for at least an hour, if it's 15-20, I plug it in for 2 hours. If it's colder than that, I stay in the house!

hwp · Nov 5, 2002

How old are you? early 60s

What the heck kind of cars did you have...? 220D, 240D and 300D Benzs - but only gas ones now

JohnMiller3 · Nov 5, 2002

Absolutely... remarkable.... young man...! /w3tcompact/icons/grin.gif

GaryK · Nov 5, 2002

I have an HSt and live in the warm south so cold starts are not a problem but I do run the newer lighter HD hydro oil and do let it run a minute or so before backing it out of the shed and several more before doing anything with the FEL or heavy work.

em14 · Nov 5, 2002

I agree with your friend .. I feel that all engines regardless, of Diesel or not, need to be warm before they are placed under a heavy load ... the metal engine components need to be heated to work at the designed tolerances and the proper lubrication is occuring. I would say that if you were to start an engine then drive at a moderate speed without hard acceleration until it has that a chance to come up to operating temp. it would last a long time .. It's not only the engine lubrication that you should be concerned about but also the transmission, final drive etc. Long periods of idling also can be bad as not only are you wasting fuel, you are adding to carbon build up in the engine...there was a nice article on the Dodge / Cummins site about this ... Now if you live and work in Alaska (harsh cold climate) there is a need to idle more unless you have some way of heating the engine oil ... I guess my take on all of this is to be gentle with equipment untill it is warm and ready to go hard ... it's sorta like being an athlete, you just got to warm and stretch those muscles ...

Anonymous Poster · Nov 5, 2002

Fire it up, warm it up a minute or 2 for lubrication purposes, work it lightly for a few more minutes, and put it to work.
Far more damage comes from immediately shutting down a hot engine.
The above relys on the presumption you are using decent fuel and the proper lubricating oil.
Much of the newer large diesel engines are now equipped with prelube pumps to prevent starting on dry bearings. The smaller engines should be regularly started & run for a few minutes to preclude dry bearings. It's always a good idea to spin the engine a few revolutions with compression released for lube purposes.

frank_f15 · Nov 5, 2002

i think the most important part of letting it warm up is that it not only brings the engine oil up in temp but just as importantly it warms up the hydraulic oil, before you work it hard. even in summer i let it warm up for a few min. and in winter depending on the temp. at least 10 min. this is only mho. but can't hurt.

Anonymous Poster · Nov 5, 2002

Hwp, the Kioti manual for the LK3054 specifically states that the diesel engine be warmed in winter and "wait until the engine is warm enough. Do not operate tractor before Temp. meter indicates the proper temperature." Later in the manual it says to always allow the engine to warm up before applying a load. I've only owned the tractor for a short time so I haven't operated it in winter. It warms up quickly during this warmer weather in Texas. Regards

ScottAR · Nov 5, 2002

When its really cold, I let mine warm up while I grease and check out everything. That takes 5-10 minutes so I'm usually ready to go. If it's really really cold, I stay inside. /w3tcompact/icons/grin.gif

Anonymous Poster · Nov 5, 2002

I always plug mine in if I think I'll need to use it in the near future (snow in forecast). If you don't have a heater and you have an electrical supply nearby, see if you can add a heater. Mine heats good enough that it also keeps the tranny oil warm too. I also let it idle for about 5 minutes before working it hard.

northcreek2624 · Nov 5, 2002

"So what is the basis of the widely held belief that diesel enignes must be fully armed up before they can be used?"

From my observation I would say the basis has two parts:
1. If it's YOUR tractor a short warm-up can't hurt just to get the oil flowing and things heated-up to reduce thermal shock.

2. If it's the COMPANY'S tractor just fire it up and go,that's what they've been doing with the JD cut where I used to work and it's still going strong after 10+ years with horrible maintenance to add insult to injury.

In summary,once running the tractor doesn't know if it's just sitting there or moving,like the other members have said,just keep the load down for a bit........Mike

JohnMiller3 · Nov 5, 2002

A few winters back, we had a cold spell down to -17 below zero… I had purchased a Satoh w/ loader earlier that summer… The Satoh being a gas engine actually started quite well considering… but the rest was terrible…

I had to let the tractor “warm-up” for about 45 minutes before the power steering worked properly and before the rest of the hydraulics would even move… /w3tcompact/icons/blush.gif

deepsnow · Nov 5, 2002

My NH dealer & service techs all recommend warming up to operating temp before subjecting the tractor to any significant load. Even using the block heater during the winter months the loader & 3pt hydro will "squeal" without a warm up. Not a problem during the summer. A simple tip to get the hydro fluid up to temp a little quicker is while idling & in neutral rock the hydro pedal. No objective data. Seems to work.