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winchman
10-04-2008, 05:26 PM
Just about every time I go to Lowes or WalMart, I'll see a diesel pickup sitting empty in the lot with the engine idling. Sometimes they're still there when I come out. Why do people do that? I see it all year 'round, so I don't think it's just to keep the truck cool or warm inside.

Are they that hard to start? Do the starters wear out so quickly that people leave them running to avoid using the starters?

Roger

radish1us
10-04-2008, 06:15 PM
If it was a large diesel motor fitted with a turbo and the semi had just been doing a long up-hill pull, then you would let the motor idle down to reduce the heat in the turbo bearings before you switched it of. A lot of the larger diesel motors fitted to semis have a timer switch so you can NOT switch it of whilst it is still HOT, say, a five minute delay after turning of the key.

Now these idiots who leave there motors running in the parking lot at Wal-mart or some such place, well they deserve to have there vehicle stolen.

No, the starter will not wear out any quicker than one fitted to a petrol motor.
It appears that the idiots who do this, are just a bunch of wankers, think they better get their hand of it before they start to grow hair on the palm of their hands.

Forrest Addy
10-04-2008, 07:09 PM
I think the reason why some people leave their rigs idling is that they're the same people who used to clothes pin playing cards so they flap on their bicycle spokes. Among other things, they like to draw attention to their presence. When confronted for the reasons their explanations are thin and don't stand up to technical examination. It's the same reason why people buy $500 putters or put straight pipes on their motorcycles. Or spend thousands on home shops or run for political office.

winchman
10-04-2008, 07:20 PM
"...people who used to clothes pin playing cards so they flap on their bicycle spokes." Guilty as charged.

And I had a straight pipe on the lawnmower engine I put on my bicycle a couple years later.

And I've spent a couple thou on home shop stuff.

Now I see. They're pretty much like me, only different.

Roger

BillK
10-04-2008, 07:38 PM
Roger,

I think this stems form an old Wives tail I always used to hear that said it used more fuel to start a dsl than it did to just leave it idleing. This might have actually been true with some of the big rig older diesels, but modern electronic fuel injection has made it a thing of the past. if it was ever true.

I will say that diesels use very little fuel at idle, but that is still no excuse. In Maryland it is illegal to leave a vehicle unattended and running anyway !

clutch
10-04-2008, 07:55 PM
Just about every time I go to Lowes or WalMart, I'll see a diesel pickup sitting empty in the lot with the engine idling. Sometimes they're still there when I come out. Why do people do that? I see it all year 'round, so I don't think it's just to keep the truck cool or warm inside.



So you will know the owner owns a diesel, like if anyone cares. Now if the guys dogs are inside, well, that is a good reason. :)

Clutch

Tim Clarke
10-04-2008, 07:56 PM
Well, I've been a diesel mechanic for over 30 years, and I've always said that those folks who won't shut 'em off don't dare to. If they had an old 5.7 GM diesel, or even a 6.2, I don't blame 'em.

Given the underhood temps of modern trucks, and the turbo itself, what happens is that with the engine off, the oil inside the turbo barbecues. Leaves a brick inside, after lots of hot soaks. I've tried to chisel a couple out. A tough go. A few minutes of idle to cool off the turbo is called for after hard runs up grades and across the desert, etc.

Mostly, I think it's ignorance on the part of the driver. Given the price of diesel, I suspect that fewer people are guilty of excess engine idling nowdays.

TC

wierdscience
10-04-2008, 08:09 PM
In 1985 my uncle bought a Ford F-250 diesel,it was one of the first to offer a diesel in that size truck.He went through 6 starters before Ford came up with one that would work.Many folks around here bought that same model pickup and the 350 starting about then and they all had the same problem until about 1988 when the starters were finally upgraded to a reduction unit.Some of it stems from then.

Many of the guys here who bought the early Ford and GM offerings left their idle and many of them have been die hard diesel owners since,old habit.

The other class are the yuppie horse "farmers" as we call them.$50,000 truck,chrome everything and trying desperately to fit in.So much so they leave theirs idling too.Most times while they are in the local feed store buying hay;) :D

lugnut
10-04-2008, 08:10 PM
I'd bet if you had been there when the "Knuckle Dragger" that parked and left his engine running, first got there he rolled down the window and listened to it rattle and rumble for awhile and also looked around to see if any one else was looking at him.:confused:
Mel

hardtail
10-04-2008, 08:37 PM
It's the same reason why people put straight pipes on their motorcycles. Or spend thousands on home shops.

Whats wrong with straight pipes and home shops..........LOL

Not defending the pickup diesel crowd in your climes but once it gets below -30C up here in winter you don't see many turned off outside, oil rigs in the bush can run for weeks. I must say though that the new diesel pickups start way better cold nowadays.

Mcostello
10-04-2008, 09:13 PM
Years ago I asked a semi driver that question. He said "I can leave it idle all afternoon on just a 1/4 tank." I said I can shut off mine for free!

clutch
10-04-2008, 09:18 PM
Not defending the pickup diesel crowd in your climes but once it gets below -30C up here in winter you don't see many turned off outside, oil rigs in the bush can run for weeks. I must say though that the new diesel pickups start way better cold nowadays.

I remember a radio program where the person from Alaska that was being interviewed commented that the locals were more interested in how many hours were on a vehicle instead of miles. :D

Clutch

A.K. Boomer
10-04-2008, 11:14 PM
I dont think this is the reason as for me it wouldnt matter anyways,--------- But - people who leave their rigs running for short periods of time instead of turning them off have extended rod and main bearing life, in fact the majority of connecting rod bearing wear is attributed to "dry starts" ------- now pump the compression ratio of the average diesel into the factor and it could actually prove to be cost effective (if your talking short run intervals)

There was much experimentation even with the common gas engine in which an electric oil pump was used to Pre-prime the rods and mains before start up -- the results were amazing as bearing wear was almost non-existent.

On the flip side - I knew a guy who was an alcoholic -- he used to leave his rabbit diesel pickup idle outside the bar for 4 to 6 hours (lunatic:rolleyes: )
came time I had to rebuild his engine and never seen a piston ring ridge that deep in so small a bore, Maybe the rods and mains where getting theres but I think the piston was lacking at that low of an idle....

Bottom line is people dont have a clue but want to act like they do, its wise to let a Turbo D or turbo gas Idle down after a hard beating --- but talk around the barbeque gets hyped and lots of guys take it to the extreme --- Fact is is turbo's have come along ways --- many only need to be treated nice just before parking and all is fine...

lugnut
10-04-2008, 11:50 PM
The thing about leaving a diesel engine running rather than shutting it off comes from back the early days of large trucks and large tractors (Caterpillar) types. The fuel was nowhere near as good as today’s and neither was the fuel pumps and injectors.
Those of you old enough and ever around the old “cats” and other large diesel tractors, remember they was started on lighter fuels then switched to diesel and or started with a auxiliary gas engine. Other words, a pain in the a$$. Diesel fuels had a tendency to “jell” at wintertime temperatures because they did not have the additives we have today. I’ve heard stories about engines that were left running continuously, because they were so hard to restart.
Mel

chief
10-05-2008, 12:41 AM
Back in the days of yore diesels were hard to start and many used a pony motor to start them, it was easier to leave them running. Peopls continue to do things out of habit or false assumptions.
When you shut your diesel your turbo has no oil unless you have an electric
coast down pump to supply oil once the engine is shut down. A turbo may spin for ten minutes after the engine is secured. Larger diesels have pre-lube pump for start up and a coast down for securing. The pre-lube pump senses press at the most remote bearing from the pump.
There is no reason to idle a diesel unless you are in the dead of winter.
The proper way to start a cold diesel is to crank and stop a few times, this will generate sufficent heat for combustion if you don't have glow plugs or a block heater.

A.K. Boomer
10-05-2008, 06:02 AM
A turbo may spin for ten minutes after the engine is secured. .


Chief, Im in agreement for the most part of your post, but the reason for having oil circulate after shutdown is not due to the fact that the turbine is still rotating, its to keep oil from "coking" on the exhaust side of the turbine bearing shaft,
If an average diesel truck engine is being idled and then shut off there is no way in hell it will spin for ten minutes, not ten, not one, not a half of one, too much drag with a part thats built intentionally with as little mass as possible, Not to mention that now instead of all the drag from the intake compressor impeller you are now trying to churn the exhaust all with plain bearings and no Mo-mo... keep in mind that if the engines being idled the turbine isnt rotating fast at all, not that this matters much as even at max turbine RPM's the turbine declines in speed at a remarkable rate due to the pressures working against it (just listen to the big rigs between shifts)...

Weston Bye
10-05-2008, 07:56 AM
I don't know about engines nowadays, but when I was a kid back in the '60s, I used to deliver topsoil for my dad. We had big Allis-Chalmers HD21 front end loaders. It started easily, cold or hot, and was turbocharged. Seems all the A-Cs we had started easily, all the Cats required some skill and work. GM diesels somewhere in between.
I would drive the dump truck up to the dirt pile and leave it running. (old chevrolet gas engine and hard to start) Start the loader, load the truck and shut off the loader. The turbocharger would whistle down by the time I climbed down and got in the truck. The dozers worked for years and the turbos never required any attention.

Spin Doctor
10-05-2008, 08:01 AM
Whats wrong with straight pipes and home shops..........LOL


Home Shop, not a damn thing. But straight pipes. I for one am getting damned sick and tired of the idiots on Harleys (well it seems to be mostly Harleys) who have to have the loudest pipes on their male extenders they can get. I have one such idiot that lives down the way from me. It doesn't matter if it is his bike or pick-up. Both are louder than they need to be and he will come screaming by 10 to 15 times a night , every night. Its bad enough I've thought about going down with a twelve gauge and "disabling" both of them. The bike and truck that is. I figure he's the type that will disable himself.

A.K. Boomer
10-05-2008, 09:03 AM
Im with you on that spin, the only thing worse than straight pipes is when their attached to a crude piece of crap wet fart mobile (harley), Have two on my block, The owners are about as advanced as their "machines" too, real prizes...

Its like their actually proud to celebrate all the misfires and inherent design flaws...

said it before and I'll say it again, I wouldnt mix cement with one of those pieces of crap...

wierdscience
10-05-2008, 09:44 AM
And then there is the other type bike rider-you've seen them 150mph to go three blocks to pick up a gallon of milk.F---ing retards.

john hobdeclipe
10-05-2008, 10:07 AM
Loud cars, loud trucks, loud "music", loud motorcycles.

There is a direct inverse relationship between one's level of maturity and the amount of noise one generates.

Lew Hartswick
10-05-2008, 11:33 AM
Loud cars, loud trucks, loud "music", loud motorcycles.

There is a direct inverse relationship between one's level of maturity and the amount of noise one generates.
Except on on the 4th of July (in the states). :-)
...lew...

kendall
10-05-2008, 12:02 PM
Loud cars, loud trucks, loud "music", loud motorcycles.

There is a direct inverse relationship between one's level of maturity and the amount of noise one generates.

Hey now! I like my music up a bit. Don't rumble the windows, but it's great to get in the truck, hit the highway and crank up some driving tunes. Gotta have it loud enough to get over the rattles.....

I have a couple amps in my truck along with some very nice speakers, but it's more for the clarity it gives the music, not the volume. If I crank it up you can hear it a block away, but I generally run with about two to four bars showing.

I don't care for loud exhaust though, many of the bikes around here you can hear for a couple minutes before they come by.

side note, I used to always get repair and report write ups with my old mustang, I got a good deal on set of period correct mags, put them on it and the R and R's magically stopped. The car was 100% stock, everything was OEM ford, just not for that year or model, and it would walk all over most of the hi-po builds

Ken.


Edit:
I have been accused of having peter-pan syndrome though.

SilveradoHauler
10-05-2008, 12:06 PM
I run 4 diesel powered trucks:

One old non-turbo Ford, a beast destined for the junk yard.

One F450, 7.3 Diesel, fully Banks equipped, after market turbo, lots of HP

One 3116 Cat powered GMC, turbo

One Pete, 3126, Cat powered turbo

So, why run them on idle?

Three of the trucks have EGT guages, if you do not run on idle to get the EGT lower than 300 degrees after a long highway run or a hard pull up a hill, then you run the risk of frying the oil in the turbo bearings, turbo bearing failure, turbine rotor failure, and a repair bill of $2500 to $4000. Yup, had to do this on the F450, previous owner pulled a big fifth wheel and cooked the turbo. It failed about 5000 miles after I bought the truck. Truck only had 40,000 miles when the turbo failed, should have went 150,000 or so.

But, only takes 5 minutes or so to cool things down, I sit in the truck and watch the EGT until it drops below 300, then shut it down. Would not think of leaving it at idle and in a parking lot, can you say a magnet for theft?? Especially the F450, it is pretty sharp looking with a aluminum hauler bed.

Folks leaving the truck running for an extended period of time are either too dumb to know what is going on (ask a real diesel mechanic about wet stacking) or they are trying to prove to the world that they are an elite diesel owner. With today's fuel cost and the number of "greenie police" it is unwise to let a diesel run for extended periods.

Willy
10-05-2008, 01:49 PM
I have probably put on several million miles as a truck driver and countless hours as an equipment operator, and as has been said by others, yes they are turkeys! For some reason they picked up on this Hollywood image of truckers idling their rigs and they have a diesel and like playing the role...jerkoffs!

Other than a couple of minuet warm up when cold, and a few minutes of cool down after a hard pull, I don't idle an engine. Even the cool down situation doesn't happen too often...like how many times do you climb a hill and jump out? Usually by the time you pull into a yard and get a rig parked it has cooled off sufficiently. I've never cooked a turbo or had other engine longevity issues, a little common sense goes a long way to keep an engine happy, and if my truck is happy I make money.

Every major engine manufacture condems unnecessary idling, they have gone to great pains to educate the industry that excessive idling is a nail in the coffin for your engine. They even have engine idle limiters in place so that after five minuets the truck will shut off by itself. These can be overridden of course for different operational parameters, such as pto use for example. Unfortunately this gives a lot of professional, (and I use the term very loosely in this case), drivers the opportunity to let the poor thing rattle itself to a slow death.

BigBoy1
10-06-2008, 08:19 AM
Home Shop, not a damn thing. But straight pipes. I for one am getting damned sick and tired of the idiots on Harleys (well it seems to be mostly Harleys) who have to have the loudest pipes on their male extenders they can get. I have one such idiot that lives down the way from me. It doesn't matter if it is his bike or pick-up. Both are louder than they need to be and he will come screaming by 10 to 15 times a night , every night. Its bad enough I've thought about going down with a twelve gauge and "disabling" both of them. The bike and truck that is. I figure he's the type that will disable himself.


Just get some very fine valve grinding compound and add it to the oil sump. In a few days the noise of him driving by will be gone!

Bill

hardtail
10-06-2008, 03:28 PM
Anybody being observed puttin foreign objects into a hawg likely has a free hospital stay in their immediate future........

I run straight pipes on the Pan put on a few hundred miles a year and my closest neighbour is 1/2 mile away, if I'm leaving home I'm going for a putt not racing back and forth past my neighbours, theres a reason I live where I chose to.......theres just as many compelling reasons to have loud exhaust when your on a bike and the gene pool and endowment isn't part of it.....LOL

Oh and I still love 2 stroke dirtbikes for a different decibel range.......LOL

Jim Caudill
10-06-2008, 05:05 PM
About 40 years ago I used to work for a fairly large trucking company (Schwerman) and, among other things, did inframe engine overhauls. Cold starts in the winter could be a beech, and the engines were fitted with inblock heaters. All trucks going out on the first run were started and warmed up by maintenance. The reason that our drivers did not shut down was due to air leaks. The trucks all used air starters, and initial "airing" was done via pneumatic lines that ran around the perimeter of the lot. Sometimes, it was necessary to air a truck a couple of times before getting it to start. If you were away from an air source and shut down the truck, the air could bleed down to such a level that it would be impossible to start. Usually this resulted in a service call by our shop folks. Sometimes we would use a wrecker, and other times we had a pickup rigged with an air pump on the engine.

http://www.schwermantrucking.com/

Willy
10-06-2008, 05:39 PM
Jim I'm surprised that those trucks did not have a dedicated air supply circuit for the starters only. Any trucks I have operated with air starters would always come with a dedicated supply circuit for the starting system.
They always had 120 psi in the system in the morning, and with the speed that the air starters would turn over an engine in conjunction with block heaters, the first start of the day was always reliable.
It always made sense to have a separate system, albeit smaller, with full pressure verses a large system that invariably had minor leaks, much like the emergency release system always being separate from the main system.
But I know it's not easy maintaining a fleet as a lot of drivers don't report minor problems until it becomes a PIA, and then you get to deal with it.
I know I always did as much of the maintenance myself as I could cause it would make my day a little easier. The day is long enough without the extra BS a guy has to deal with when stuff doesn't work.

Metalmelter
10-08-2008, 07:40 AM
Or spend thousands on home shops or run for political office.


Are you kidding me :rolleyes:

May as well throw yourself in that class too. But than again companies like HP/Agilent wouldn't have come without the beginning of a home shop either. In fact it's now a National Historic Landmark :)

http://www.hp.com/hpinfo/abouthp/histnfacts/garage/

You'll love this!
http://www.kennethkuhn.com/hpmuseum/garage/

Your Old Dog
10-08-2008, 07:47 AM
This has been a useful thread for me. I have the F350 7.3 liter diesel for towing my travel trailer. I didn't know about the problems of shutting down too quickly after a long hard pull.

I know my neighbor left his Case tractor running overnight during the winter because he once cracked a piston starting the tractor in cold weather.

I only leave mine running if I haven't driven far enough to evaporate the moisture out of the oil.

I purchased a remote control used on Christmas lights so I can turn on the block heater if I'll be using the truck that day. Beats the hell out of wading through knee deep snow to plug it it. I checked it with a Kill-O-Watt meter and it cost me something like 50 cents per morning to put it on a timer to turn on 3 1/2 hours every morning or about $15.00 to the electric bill per month. The remote switch works much better for me.

I've read somewhere that ideling the engine puts the same amount of wear on the engine as driving it. 10 minutes of ideling is the same as driving 10 miles down the road. Maybe it's an old myth also but I've heard that diesels like to be working under load and not loafing for longer engine life.

If you see mine running, it ain't because I'm boasting that I can afford $5.00 per gallon fuel or that I enjoy the loose sloppy sound of a finely tuned diesel ! :D

gregl
10-08-2008, 02:04 PM
I had heard that lengthy idling was only for wet sleeve engines, and that truck engines are not of that variety. Anyone know more about this?

Jim Caudill
10-08-2008, 07:35 PM
I don't know what you mean when you use the term "truck" in the phrase "that truck engines are not of that variety".

The semi tractors that I worked on used wet sleeved cylinders in the Cummins engines and dry-sleeved cylinders in the Macks. So, at least in this class of truck, both types of cylinders were used and the both were left running due to "air leaks".

davidh
10-09-2008, 06:44 AM
back in the days (mid to late 60s) i owned various mercedes benz 4 cylinder cars, real buggers to start in the cold. i use to say making them start inthe cold was like putting a blob of vasoline in your palm and slapping your other hand on it, hoping it would explode. here in the frozen north, we used to have a couple weeks in january that the temp would not get above zero in the daylight and would hit - 40 or so at night (F). i would let my baby cars run all the time, locked of course, shutting them off only to check oil once in a while. these older m.b,;s had dash mounted idle adjustment knobs so you could turn the rpm up just a bit over an idle so the engine would not cool down to outside temp. but in the morning you could lay your hand on the exhaust manifold and it was very cool. however, i was told that after sitting all night pissin off the neighbors, not to rev them up to high until they got a tad warmer than what they were from sitting. . . or you would blow a hole in the piston. never had it happen but the theory sounded ok. seems if they run too slow they will cool down to near ambiedent temp except for right in the top of the piston where the "fire" was happening. . .

i also read somewhere that fuel consumption on a diesel is based on only what is needed to overcome the friction of making the engine and acessories turn. in other words "lbs of fuel per horsepower hour". this was from an old cummins engineer. i do believe he was right as i could barely use any fuel for overnight idling. damn fine little engines these were, now i have a couple 5 cyl. turbo diesels in a couple older mercedes. same fine little engines, just a bit more complicated with all the controls and accessories operating on vacuum.

wow is this OT or what. sorry had to ramble. more coffee needed. . .

A.K. Boomer
10-09-2008, 07:58 AM
David, Depending on the year --- Mercruisers can be a funny breed of diesel --- I know some of the early ones actually had a throttle plate, this can aid in vacuum controlled mechanisms like you stated --- most diesels dont have a plate and run an aux. vacuum pump for power brakes and such because they cant achieve vaccum on their own, the fact that you stated that you could let your cruiser run all night and the exhaust manifold was still cold to the touch makes me think you had one that was a little later and it had no plate, when you have no plate you run full bore wide open air charge, there's pro's and con's to everything,
the main advantage (which is huge) is that you ensure maximum engine efficiency because you no longer have to worry about metering the throttle plate air charge with the fuel charge, all engine speed operations are a direct result of the amount of fuel injected and the timing at which its done --- this is huge as it eliminates much added componentry and also ensures the proper amount of oxygen needed to burn whatever the fuel injected - diesels dont need the "perfect mix" of fuel/air, all they need is fuel and enough or far more air needed to get the job done --- in some instances air to fuel ratio surpasses 150 to 1, doesnt matter -- the fuel will burn -------------- The con's --- diesels that dont use a throttle plate have trouble in some area's, in the winter they can cool too good due to the fact that they are allowing massive amounts of air through the engine with little fuel actually being burnt (idle) The ford power stroke takes care of this by utilizing an exhaust restrictor that is linked to engine temps, it will be sitting there idling and then sound like a jet engine, this is to create enough backpressure to hold the heat in as it restricts the CFM's,
As mentioned Diesels with no T-plate have to run an aux. vacuum pump due to the fact that they cannot make vacuum on their own, Also - diesels with no T-plate go through air filtration systems like crazy, even at idle they are consuming vast amounts of CFM's.

On the flip side, the pro's to having a diesel with a T-plate is of course readily available vacuum --- longer lasting air filters --- engine temp holding capabilities even in extreme cold.
The cons are now you have to worry about proper metering -- Much more apt to get "sooting" and waste precious fuel as certain situations throughout the range can create more fuel than the air supply needed to burn it, there is not only more room for error the metering system itself adds complexity.

But I have to add that there is also room for error when the diesel with no T- plate plugs its air filter early and someone creates high air/fuel demand -- now they mimmick a throttle plate of sorts or at least a restriction at full throttle high RPM's --- due to the lack of meter/monitoring they can suffer efficiency losses because they are injecting a full spritz of fuel without the expected full air charge needed to burn it, this however is limited to the highest demand (full throttle high RPM) first and most - and if left unchecked can trickle down into higher midrange as the filter gets more and more plugged.
One of the best things they did for the no T-plate diesel engine is install those air filter vacuum gauges in the filters housing - it tells you if the filters good at a glance -- they know how critical this is for optimum perf. and efficiency on these particular engines...