Poll: How long will you let your diesel idle? - Page 5 - PeachParts Mercedes-Benz Forum

t walgamuth · #61 10-28-2006, 03:11 PM

i have on occasions left it idle all night on a trip with 20 below weather. also all day at work if same weather. idling all day takes maybe a gallon or two.

tom w

seo · #62 10-28-2006, 03:49 PM

I live in Maine, and have business in Minnesota, and sometimes drive back and forth in my 300d. My old 240d had a block heater, but the 300 doesn't. Nonetheless I've always been able to start it in the winter. Here are my tricks.
Park on a hill. At -20 my car starts fine if I bump-start it, cycling the glow plugs while the car rolls down the hill til it hits about 10mph, then keying the starter and dropping the clutch in 2nd gear. All the inertia of 4000 Lbs rolling downhill goes through the engine, and she starts, no maybe. Sorry about you guys with auto transmissions.
In really cold weather, I put 10% gasoline in the fuel. No kidding. This is recommended in European manuals for VW diesels, and I think for Mercedes too. Works fine. If I'm on the road, I drive all day on straight diesel, then estimate how much fuel is in the tank, add 10% of gasoline, drive a block or so to mix it up, and park. In the morning I top off with diesel. At times when I've had to mix a full tank with gasoline I never noticed a difference in power, and only a slight (1-2 mpg) change in economy.
If this sounds really crazy, reflect on the fact that 1950's International Harvester tractors and bulldozers had a gas tank, carburetor, magneto, and plugs on 3 of 6 cylinders. You started on gasoline, and once the engine was rolling and a little warm you'd turn on the injection, and away she'd go. This was the same time when Cats had an entire extra 2-cylnder gasoline "pony" engine for a starter.
Aside from having an engine that runs well, make sure that you have a really good battery.
When I used to drive up to northern Maine and Quebec in winter, I had a pretty elaborate rig, consisting of a block heater and also a 1000 watt electric space heater mounted under the hood, blowing mainly at the battery. It's remarkable how much power a battery loses as it gets really cold. With those two heaters running for just an hour, the 240d would start right up at -40.
As a final thing, I think rather than install some weird battery/inverter in the trunk, or a propane-fired block heater, I'd just buy one of those very good little Honda generators, which weigh about 20 Lbs, and use that to power an electric block heater. Among other things, you'd have a nice little generator for other purposes.

diesel don · #63 10-30-2006, 07:53 AM

Wow.

You have some great ideas there. The 'good battery' comment is tricky because at times, some of my batteries have faked me out. But when replaced they spun it so much quicker in the cold.

Thanks for the input

dp

vstech · #64 10-30-2006, 10:24 AM

Quote:

Originally Posted by seo

I live in Maine, and have business in Minnesota, and sometimes drive back and forth in my 300d. My old 240d had a block heater, but the 300 doesn't. Nonetheless I've always been able to start it in the winter. Here are my tricks.
Park on a hill. At -20 my car starts fine if I bump-start it, cycling the glow plugs while the car rolls down the hill til it hits about 10mph, then keying the starter and dropping the clutch in 2nd gear. All the inertia of 4000 Lbs rolling downhill goes through the engine, and she starts, no maybe. Sorry about you guys with auto transmissions.
In really cold weather, I put 10% gasoline in the fuel. No kidding. This is recommended in European manuals for VW diesels, and I think for Mercedes too. Works fine. If I'm on the road, I drive all day on straight diesel, then estimate how much fuel is in the tank, add 10% of gasoline, drive a block or so to mix it up, and park. In the morning I top off with diesel. At times when I've had to mix a full tank with gasoline I never noticed a difference in power, and only a slight (1-2 mpg) change in economy.
If this sounds really crazy, reflect on the fact that 1950's International Harvester tractors and bulldozers had a gas tank, carburetor, magneto, and plugs on 3 of 6 cylinders. You started on gasoline, and once the engine was rolling and a little warm you'd turn on the injection, and away she'd go. This was the same time when Cats had an entire extra 2-cylnder gasoline "pony" engine for a starter.
Aside from having an engine that runs well, make sure that you have a really good battery.
When I used to drive up to northern Maine and Quebec in winter, I had a pretty elaborate rig, consisting of a block heater and also a 1000 watt electric space heater mounted under the hood, blowing mainly at the battery. It's remarkable how much power a battery loses as it gets really cold. With those two heaters running for just an hour, the 240d would start right up at -40.
As a final thing, I think rather than install some weird battery/inverter in the trunk, or a propane-fired block heater, I'd just buy one of those very good little Honda generators, which weigh about 20 Lbs, and use that to power an electric block heater. Among other things, you'd have a nice little generator for other purposes.

this set of hints should be posted in one of the stickeys up above!
John

vstech · #65 10-30-2006, 10:33 AM

only thing I can add to this, is fuel tank heater... In extreme cold winters in SD, (-100*F)

our Massey Ferguson tractor would be the only one in the area that would start and continue to run. the block heater heated not only the coolant and the battery, it also heated the fuel tank, due to it's being right on top of the motor. all the Newer tractors in the area had the fuel tank over the rear wheels, like our benzes do. so some way to heat the fuel tank may be needed if summer mix fuel is in the tank on an extreme cold night.
John

Jeremy5848 · #66 10-30-2006, 11:02 AM

Quote:

Originally Posted by henrydupont

...an inline heater near the radiator seems no option, considering the thermostat is closed so the hot water won't circulate into the block?

I'll let you know in December when I visit snow country!

A heater in the lower radiator hose (mine came from DieselGiant) is about the only option for those of us cursed with the Californicated 1985 model 300DT. The right side of the block is so covered with plumbing that you can't even see the plug for the factory block heater, much less get at it.

I've wondered about your heat circulation comment. Maybe I'll PM DieselGiant, see what he has to say on the subject.

Jeremy

GREASY_BEAST · #67 10-30-2006, 01:31 PM

I installed an Espar last winter, which heats the engine to 80°C in about an hour, and I idle for about 5-10min when its chilly to make sure the oil is warm (espar heats the coolant, oil still sits down there in the pan, which is somewhat warm to the touch but not hot like the valve cover). I know most people don't want to deal with it/don't think they can afford one, but I figure that because I burn free WVO, it won't take very long, maybe 5 years, to pay for itself in fuel savings (running espar for 2 hours + driving on diesel for 2 minutes = high enough temp to switch over), and it sure is nice to be able to shut the car off in places that don't have electricity. I even use it in the summer to heat WVO before starting.. this summer I saved quite a bit of diesel fuel that way. Keep in mind that the espar only uses about 1cup of fuel/hour.

vstech · #68 10-30-2006, 02:24 PM

Quote:

Originally Posted by GREASY_BEAST

I installed an Espar last winter, which heats the engine to 80°C in about an hour, and I idle for about 5-10min when its chilly to make sure the oil is warm (espar heats the coolant, oil still sits down there in the pan, which is somewhat warm to the touch but not hot like the valve cover). I know most people don't want to deal with it/don't think they can afford one, but I figure that because I burn free WVO, it won't take very long, maybe 5 years, to pay for itself in fuel savings (running espar for 2 hours + driving on diesel for 2 minutes = high enough temp to switch over), and it sure is nice to be able to shut the car off in places that don't have electricity. I even use it in the summer to heat WVO before starting.. this summer I saved quite a bit of diesel fuel that way. Keep in mind that the espar only uses about 1cup of fuel/hour.

Neat, but what do they cost?
Which model do you have installed? do you have any pictures?
John

WD8CDH · #69 10-30-2006, 02:47 PM

Don't cycle the glow plugs several times in the cold. Just leave the key in the glow position for 10 seconds or so after the light goes out and then crank the engine. What many people don't know is the glow plug light just indicates when it is time to start cranking on a well tuned engine. The glow plugs stay on even after the light goes out for half a minute or so.

Also the "violet wire mod" will keep the plugs on during cranking for easier starting in the cold with the older MBs.

GREASY_BEAST · #70 10-30-2006, 03:09 PM

Quote:

Originally Posted by vstech

Neat, but what do they cost?
Which model do you have installed? do you have any pictures?
John

I got a Hydronic D5 from Lubrication Specialist for about $900 last year. Installation was pretty easy. I made a bracket that mounts just aft of the windshield washer tank to hold the unit, and T-ed in to the heater hose near the oil filter and put the return into the heater hose coming off the passenger-side of the block btw. the block and the aux. water pump. I don't have any pics but I might take some soon.

Old300D · #71 10-30-2006, 05:57 PM

Quote:

Originally Posted by seo

...
Park on a hill. At -20 my car starts fine if I bump-start it, cycling the glow plugs while the car rolls down the hill til it hits about 10mph, then keying the starter and dropping the clutch in 2nd gear. All the inertia of 4000 Lbs rolling downhill goes through the engine, and she starts, no maybe. Sorry about you guys with auto transmissions.
...

Sorry, wrong. This works with Benz automatics as well, as they have a rear pump. I've roll-started mine.

captainmonk · #72 10-30-2006, 06:15 PM

my first caterpillar engine on the boat had a gas pony engine to crank her over fast enough to start her up as long as i could find the spark plug My isuzu powered generatorhas been running for over 35000 hours except for oil changes since ohhhhhh around 1986 I never shut off the main engine if i can help it out to see the tow truck is sooooooooooooooooooo far away

POS · #73 10-30-2006, 06:22 PM

I don't let it idle - it's only good for the engine if it's too hot to shut down. The big trucks and the PowerStrokes have idle controllers that get the idle up to 1200 - less damage that way.

Still, I wouldn't do it for long.

GREASY_BEAST · #74 10-30-2006, 06:31 PM

Quote:

Originally Posted by POS

I don't let it idle - it's only good for the engine if it's too hot to shut down. The big trucks and the PowerStrokes have idle controllers that get the idle up to 1200 - less damage that way.

Still, I wouldn't do it for long.

Speaking of which... it seems like it wouldn't be any big deal to set up a throttle on a 617.. just make a bracket that picks up those 2 bolts on top of the valve cover on the IP side. Those flexy-cable-in-a-sheath things are easy to scrounge up off a lawnmower or tractor or something... evening project. Cheap cruise fix too

pawoSD · #75 10-30-2006, 07:48 PM

Idling a 617 is expensive, they use about a gallon every 3 hours at normal idle, and probably every 2 hours if they are at like 1000rpm. That'd be $10-13 a night in fuel just to idle it, not to mention how often you'd have to get fuel if you're burning off 3-4 gallons a night. $13 x 7 = $91 a week just to idle the engine. x 20ish weeks of winter = $1800 per year. I think I'll go with a rebuild every 300k instead, and forgo the extra 50-100k the engine would have lasted. If the engine lasts 20 years and 300k with cold starts all the time like normal, then it has easily payed for its rebuild vs leaving it idling and using fuel.

If the temps were super cold (too cold to start it back up) for a little bit I'd consider idling it a few times for that reason, but if it was an on going problem I would have a diesel or kerosene coolant heater installed. They use about 1/10gallon of fuel per hour and can get the engine to near operating temp in less than 3 hours. Much much more efficient. Even big locomotives have new technology that lets them shut down if they'll be sitting for a while, they only keep those running if the temps are going to be below 40F or if it will be less than a few hours of sitting.