Oil & Fuel Need to Warm Up a Diesel Engine?

[deepsnow]

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. Warm up period provides a good time to do a walk around checking for potential bad things like loose lug nuts.

 

[BobCorazza]

I warm my tractor up prior to any use other than leaving the shed. Putting around with limited load seems prudent enough though. In the winter I use a 250 watt magnet heater on the oil pan and a 500 watt light under the tranny for several hours. So even on the colder (teens) days 5 minutes of running seems to be enough.

 

[robertm]

HWP,
I addressed this question with my dealer and he said to wait at least until the temperature needle moves from the position it was in when you started it. Only pushing 35 hours on a new Kubota B7500, but I believe a little warm-up time can only help. It's like gettin' out of bed on a cold morning... do you want to hammer down and run the 500 before warming up? /w3tcompact/icons/laugh.gif

 

[RichC]

Page 22 - "Operator's Manual"
Kabota Tractor Models B7400 - B7500

"For five minutes after engine start-up, allow engine to warm up without applying any load, this is to allow oil to reach every engine part. If load should be applied to the engine without this warm-up period, trouble such as seizure, breakage or premature wear may develop."

It goes on to talk about transmission oil and low ambient temperatures. Basically, it reads warm up time required for temps above 32 degrees - at least 5 minutes.
32 to 14 degrees - 5 to 10 minutes
14 to -4 degrees - 10 to 15 minutes
below -4 degrees - more than 15 minutes.

My new tractor came with instructions!

 

[IRTEXN]

Rich, Didn't you know it will void your warranty if you are caught reading instructions.....almost as bad a asking for directions..HA!...Just kidding

 

[Bird]

<font color=blue>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</font color=blue>

John, that reminds me of a neighbor's experience with an older used Oliver diesel that he bought a few years ago. Not nearly as cold down here in Texas, but on one of our colder mornings shortly after he bought that tractor, he started it up and had the same problem you had. He told me he left it running while he went back in the house and called the dealer to complain about it breaking when he'd only had it a few days. The dealer told him, "By the time you get back out there to that tractor, I'll bet everything is working." It was, and the neighbor told me felt like a fool for calling the dealer./w3tcompact/icons/laugh.gif

 

[hwp]

Thanks for the great discussion. I'm convinced. I was talking to a friend on mine, a Benz mechanic, and he told me that the major concern is rapid cooling of the block when the thermostat opens. If a diesel engine isn't allowed to warmup gradually but is put under load too quickly, then at the time the thermostat opens, the block will be very hot around the cylinders from the combustion process and the sudden rush of cold coolant from the radiator can cause the block to contract and seize the number one piston. He explained that this is due to two reasons: the first is that the block of a diesel is much heavier due to the need to withstand the higher pressures from the higher compression, and therefore there is more metal to contract and second, the tolerances in a diesel engine are tighter, again to meet the higher compression pressures, so there isn't as much ability to accomodate the contraction of the block when the coolant first starts to flow. When I asked him why this isn't raised in the Benz owner's manuals he said that is was because a diesel engine in a car usually isn't worked hard enough to matter, but that he had seen it happen. So the message I get is to warm up the diesel before putting it to any heavy work.

 

[gerard]

Seems to make some sense but my knowledge of thermostats is that they also open gradually - it's not an open/shut arrangement per sey.

 

[Anonymous Poster]

<font color=blue>Seems to make some sense but my knowledge of thermostats is that they also open gradually - it's not an open/shut arrangement per sey. </font color=blue>

I once questioned whether a thermostat was working properly in some vehicle I owned, and so took it out and put it in a pot on the stove and watched it as the water heated.

The thing that I remember surprising me was that it opened pretty quickly once the temperature that it wanted to open at was reached.

It was not a snap switch from closed to open, but it was fairly quick...

Bill in Pgh, PA