Warm up time?

BruceW · Jun 8, 2001

The manual for my 3010 recommends 5 minutes warm up time for the long term health of the engine. Do most people do this? Does the tractor have to sit without moving for 5 minutes or does this just mean don't put serious load on the tractor for 5 minutes? I store my tractor in a barn so I currently start it up, back it out and then let it idle for a few minutes. Does this fit the bill or might I be creating problems for down the road?

bruce

FarmerBob · Jun 8, 2001

Bruce...

My L2600 manual says the same thing. My dealer says there is no break-in required, but I always let mine sit and run for about a minute or two after starting. I figure that gives the fluids a chance to circulate. I have noticed that if I have an implement attached to the 3PH and it's in the raised position when I start the tractor, after about 30-seconds of idle the tractor lurches a bit. I assume it's caused by the weight of the implement and the pressure exerted on the hydraulics. I'll ask my dealer when the tractor goes in for the 50-hour maintenance.

FarmerBob

RPM · Jun 8, 2001

It's important to allow the engine to warm up. The fluids (hydraulic and oil) only exhibit the optimal physical properties once they are in the normal operating temperature range of the engine. This is particularly true if you are not using synthetics.

There are also significant forces acting on the engine block and other relatively thick components due to thermal stresses - particularly in cold weather. Even if you use synthetics they don't help the block heat any quicker - applying a high thermal load by working the engine before it has warmed up will only serve to shorten it's life.

I like to see the needle on my temperature gauge get off the starting blocks before I start engaging the PTO or apply any other load. To tell you the truth I usually spend 5 minutes tidying up some of the junk my kids have usually strewn around the garage before I get going!

RPM · Jun 8, 2001

To answer your question specifically (sorry) - moving it out of the barn and then leaving it for 5 minutes won't do it any harm. Your life might be shorter than the tractor's if you leave it idling in the barn along with yourself for any length of time due to Carbon Monoxide build-up!

kubmech · Jun 8, 2001

Have your dealer check the feed back linkage for the 3ph. You need a little play at the top of the lift arms with the hitch raised all the way up to ensure the hitch kicks out of relief when fully raised. And allow some room for the piston to "bounce" a little while heading back to the house for lunch. This also keeps the hydraulics from continuously running over relief (bad thing). What may be happening is after start up the hitch raises a little to make up for the normal bleed down of the hitch with the weight of the implement. That may be your lurching. Quick way to check: With the implements removed engine at idle, note rpm, raise the hitch all the way up while watching engine rpm, when the hitch reaches the top, rpm should return to previously noted. Manually lift up on the hitch arms, there should be about 1/4 inch of freeplay prior to reaching full lift height (make sure the play is in the hitch and not the splines).

GlueGuy · Jun 9, 2001

My manual says the same thing.

My usual routine is to start it, wait for 20 seconds or so, then raise anything on the 3PH, and the FEL, then back it out into the world. While it is still idling, I get off put up the ROPS & put in the bolts for the ROPS. This takes a couple minutes. I then keep the RPM relatively low while I transport to where-ever I'm going to be working. Total time is probably about 5 minutes.

The GlueGuy

Harv · Jun 9, 2001

The manual for my L2500DT says to warm it up for 5 minutes with no load, and then 10 to 30 minutes or more before applying full load, depending on ambient temperature.

My baby sleeps indoors, however, so I fire it up, wait 30 seconds (just to be better than GlueGuy /w3tcompact/icons/wink.gif) before raising the FEL and 3pt implement. I then ease her just out into the open and set the brake. Then, before I hop off, I set the throttle to about 1,000 rpm, as also recommended by the manual, for the rest of the warmup.

I putter around for about 5 minutes or so, by which time the temperature guage is just about at half scale. That's the normal operating temperature for my 'Bota, but as we've discussed in other threads, many guages barely register anything at operating temp.

On a side note here -- the manual also says to pre-heat the engine glow plug thingy for 20 to 60 seconds (depending on ambient temp) before cranking it up. The dealer (and they're never wrong, are they?) said that wasn't really necessary in our California climate, so I never have. The coldest air temperature I've ever tried to start up in was about 38 degrees F, and, like always, it fired up instantly.

So tell me, mechanic dudes -- are there other reasons than fast starting for preheating? Am I damaging the engine with my cavalier approach? /w3tcompact/icons/crazy.gif

r0GuE · Jun 9, 2001

Well heck! if the dealer said so!!!!
Those Japanese guys who wrote the manual son't know anything about warm weather (South Pacific Rim). I'd go with whatever Clem sais!! ;^)

Rogue

jdkid · Jun 9, 2001

Hi ya
pre heat is only needed in realy cold places ,even here in NZ my tractor lives in the big blue shed on cold days 20 F with no preheat it fires up frist time landcruser needs it now and then tho .snow and white frost are good signs ya may need to preheat abit

RPM · Jun 9, 2001

Careful there now Rogue - the tip of Japan's northern island of Hokkaido is at the same latitude as the northern states of the US (Montana etc.)

Average minimum temperatures in Sapporo - one of the largest cities up there can be found here and here.

Lots of ski resorts up there too ...

StoneHeartFarm · Jun 9, 2001

only exhibit the optimal... 

I read a 4x4 mag that basically said oil gets ropey at low temps. So, when you start the engine, it splashes around and hangs on the inside of the block and crankcase. Until the engine warms up and thins the oil it will not flow down into the sump real fast and your engine can wind up oil starved since there's not enough in the sump to supply the pump. Which is why they make 5W-30 oil. Is that basically correct?

SHF

r0GuE · Jun 9, 2001

Ok ok...
You got me, but they have really warm areas too.

Rogue

BruceW · Jun 11, 2001

Thanks for the advice on engine warm up with an especial thanks for the lessons in geography and climates around the world.

bruce

StoneHeartFarm · Jun 11, 2001

Okay, so we digress. You gotta admit it's cool, though. Kinda like sittin on the front porch and yakkin with the guys.

But I still want to know if anyone else thinks this stiff oil not running into the sump is the real reason behind long warm ups.

SHF

Hawgee · Jun 11, 2001

Ya, I can remember Dad talk'n bought the early days when they drained the radiator at night too. Even if you pour in a new warm gulp of morning oil, the cast metals and steel against softer bearing surfaces are not ready yet. The only thing that would get me out of bed any qwicker would be a house fire.
Fire! That would be one time not to worry bout warm'n up. /w3tcompact/icons/laugh.gif

Thanks to Muhammad for the edit feature.
News Flash. Just saw GW's speech on global warming on MSNBC cable. To listen to him, I guess there is a fire. This means no warm up and no idle'n. Your operators manual will be rewritten. /w3tcompact/icons/laugh.gif I don't see the Federal Gov. replacing engines that have worn out with less than 1000's of hours.

"What is a weed? A plant whose virtues have not yet been discovered."
Ralph Waldo Emerson (1803-1882)Edited by Hawgee on 06/11/01 11:36 AM (server time).

FarmerBob · Jun 11, 2001

Thanks a bunch kubmech. I've got my 50-hour coming up in a couple of weeks and I'll have my dealer check it out then. Doesn't seem to be causing any problems during normal operation.

FarmerBob

skent · Jun 11, 2001

Stationed at the Small Boat Station in NY Harbor in the 70's. Most of the boats (30 and 40 footers) had twin diesels. Some were Cat engines, some were Detroit Diesel, Duty boat and standby boat had to have preheaters on and a seaman made rounds every half hour and logged the engine temps. The 41 footer had a V4 Cat engine for the fire pump - it had it's own heater too. Usually the heaters were sized to keep engine temp in the mid 130's. (seems to me they were around 1500 watts each) Ran the heaters even in summer. When you gotta go. . . you gotta go! I guess it kept the engines in one piece.

Steve

RPM · Jun 14, 2001

SHF said But I still want to know if anyone else thinks this stiff oil not running into the sump is the real reason behind long warm ups.

Stiff is probably not the right word - but viscous is. Here's my stab.

I doubt that the problem is oil not returning to the sump. There's typically ample oil in the system (with special exception for Rogue's BX /w3tcompact/icons/crazy.gif!) to not have to worry about this.

I believe that the warm-up has more to do with tolerances between components in the engine - and how the oil lubricates between those moving parts. Ideally, you should wait until the oil has warmed up sufficiently that it reaches its ideal viscosity and flows easily in between these components. You then have a nice lubricated film that minimizes wear. This is why synthetics are good - they are close to their desired viscosity even at low temperatures (they also don't lose too much viscosity at high temperatures - unlike dino juice oils).

These tolerances change as the components heat up, so it's also good to wait for this change to happen before loading the engine. Cast iron, steel, aluminum etc. all have different coefficients of thermal expansion - i.e. expand and contract at different rates - so this problem is accentuated if you have components machined from different materials.

What happens if you load an engine while cold? Well, that applied load will tend to force these components against one another (e.g. no shaft is perfectly balanced rotationally). These components with tight tolerances (e.g. crankshaft with other rotating/reciprocating components etc) will tend to press against one another harder. If the lubricating oil film is insufficient you will get excess wear.

You are almost always bound to have some oil film left from the last time the engine was running. What you need though is a flow of lubricant. To get that to the critical tight spots you need the oil to be the right viscosity.

Of course, on the other end of the spectrum - for a worn engine with slack tolerances you want to use a heavier oil to 'fill the gap'.

Hope this makes sense - I'm no tribologist so I'm not convinced I'm right.

StoneHeartFarm · Jun 14, 2001

Makes sense. Pistons are aluminum. Rings are steel or some exotic stuff. Cylinders cast iron? All three are going to expand and contract at diffrent rates. I would suspect the engineers have it worked out so that the COLD engine may even have a little slop in that ring/piston/cylinder combination so that a HOT engine will have tight fitting parts. I think the amount of oil film left on parts though would depend on the length of time the engine has set.

SHF

RPM · Jun 14, 2001

With regard to the amount of oil left coating surfaces after the engine is turned off ...

At a microscopic level, the machined surfaces are still somewhat rough. The oil can therefore cling to these surfaces - although it will be in small quantities. Over time (weeks, months) that thin film will evaporate if it is a fairly open surface - such as the cylinder walls. That's why you can still get rust inside an engine if left unattended for a long time resulting in all kinds of other problems.

A couple of comments ...

First, do you remember the commercials where there are two engines running side by side - one has an oil additive (can't remember the brand) and the other doesn't. The oil is drained from both systems and the engines are left running. The engine without the oil additive seizes quickly. Point of the commercial is that the additive adheres to the internal surfaces of the engine and improves lubrication - I can't vouch for these products, but this illustrates the problem quite well.

Second, a more controversial subject is 'cool down' for an engine. If you've been operating under load for a long period of time you should allow the engine to return to its normal operating temperature before turning it off. Why? For a start, the normal (not synthetic) oil viscosity drops off at high temperature. This makes it 'runnier'. If you turn the engine off at high temp then you will lose some of that beneficial film of oil that is left behind in the critical areas where there are moving parts and tight tolerances. The problem is compounded because the retained heat in the engine will serve to drive off the remaining oil film by vaporization.

There are also other factors such as thermal stresses invoked because of uneven cooling - oil acts as a coolant as well as a lubricant (never mind the rest of the cooling system being turned off!). Added together, not allowing your engine to return to normal operating temperature causes as harsh a wear environment as not warming it up correctly.

This is the cause of many of the problems with engines when someone runs it hard, turns it off and then wonders why the engine has seized.