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Old 04-15-2008, 11:42 AM
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45 minutes, I admit it's long. But especially on diesels which have high compression ratios and are heavier/harder to rotate - every 10-15 minute errand you complete while idling the car is one less crank on the starter.

Any given starter has a finite number of cranks in it. Whether that number is 10 million, 1 million, 1 thousand... who knows. Every one will be different... but nonetheless, every unnecessary crank is increasing the counter.

"What could possibly go wrong?"

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Old 04-15-2008, 11:43 AM
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used to leave their trucks idling for long periods of time.

Detroit Diesel recommends against it
Caterpillar recommends against it
Cummins recommends against it
Mercedes-Benz recommends against it.

So unless the driver is not paying for the fuel nor the maintenance, he will probably shut down.

Originally Posted by Dee8go View Post
I guess that's why truck drivers often leave their rigs idling for long periods of time.

Gone to the dark side

- Jeff
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Old 04-15-2008, 11:52 AM
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His profile has this in it
destroying cars, and rebuilding them.
diesel engine mechanic
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Old 04-15-2008, 12:11 PM
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When I do a diesel purge my near-half gallon bottle empties in about 15 minutes. You can really see the usage at idle when doing a purge. More than you would think....... {and that is with the return going into the same bottle of course}

We certainly wouldn't want to just responsibly drive them like so many people have been doing since the 70's. We want to trick things up and feel like we are accomplishing something that is just a little smarter than the average guy.
I'm just sayin'..........
Jimmy L.
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Old 04-15-2008, 12:40 PM
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Originally Posted by Dee8go View Post
I had that thought, too. Forty-five minutes of idling with diesel selling for >$4.00 a gal. sounds pretty extravagant.
What does he care, he is burning $3.25 Gasoline in it.
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

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Old 04-15-2008, 01:26 PM
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Why would you let your car idle for 45 minutes? Your wasting a ton of fuel and sooting up the engine. Now that its warmer out just start it up and go. You have a NA diesel so you don't need to do anything special. On a turbo charged engine its a good idea to stay off the boost until it warms up a bit. Their also is no reason that you need to let it idle down. You only need to do that on turbo charged engines if you just came off boost, you have to give the turbo a chance to slow down. On a NA engine this is pointless.

Running gas is probably a very bad idea, these are diesels after all....

Diesel cost $4.25+ a gallon up here, I was pissed off that I had to idle the SDL for 20 minutes today after I changed the coolant.
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Old 04-15-2008, 01:58 PM
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1) As has been stated about 100 times already, 45 minutes of idle is unnecessary, pointless, a waste of fuel, and just needless wear-and-tear on the engine. Idling is not good for any car for an extended period of time.

2) Gasoline is really terrible stuff for your diesel engine. If you need a "thinner", use kerosene.

3) Why would you add new motor oil? It has a bunch of additives that are designed to PREVENT it from burning.

All that said, sparks (despite meaning that you are destroying your engine) probably looked pretty cool.
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Old 04-15-2008, 01:58 PM
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Originally Posted by pawoSD View Post
Lately I've noticed that I see almost no idling diesels ever, not even the big rigs.....
In some states, idling a commercial diesel is illegal. Pollution, I imagine.
And letting our engines idle for a bit is not going to hurt. If you have a working t'stat, it'll come up to temp, and stay there, regardless of whether or not you're moving, so once it hits 80c, or whatever temp your car runs at, you are wasting fuel, albeit, not much, according to some.
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Old 04-15-2008, 02:19 PM
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Not always. Around here when the engine temp comes up, and it's zero out, the heater pulls enough heat from the engine to keep it below proper operating temps at idle.

Besides that, it isn't the coolant temp that is important, it's the cylinder temps that stay on the cool side and can foul the rings.

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- Jeff
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Old 04-15-2008, 02:34 PM
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Originally Posted by thesst View Post

3) Why would you add new motor oil? It has a bunch of additives that are designed to PREVENT it from burning.
Ok how about used oil, will it burn easer/better?
If someone wonted to add a quart to a full tank of diesel to lube things up some.
Or would that bring your mpg down adding used oil to diesel fuel.
Just wondering
Not talking about synthetic oil.
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Old 04-15-2008, 02:36 PM
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Originally Posted by Cervan View Post
So i run my 1981 240d pretty hard, its a manual 4 speed. I usually let it sit on the rev limiter in all four gears if i can. (Only to clean it out these engines love to howl) So today i drive to work, just like usual. And before i leave i start the car and let it idle for about fourty five minutes before i leave. Now, before all of this i had added gasoline to the fuel tank with about three gallons of diesel and a quart of engine oil to lubricate the IP. So i get in my car after it idled for allmost an hour, drive off everything is fine, shes howling through her gears. And i drive home, wich i live about an hour away and decide to get some clothes and oil to do an oil change on this car. As im going through the walmart parking lot i let the car get up to about 4k rpms, not on rev limiter but up there and then i glide into my parking spot and let it idle for a few seconds, to cool the oil. I shut it off and get out lock the door and start walking to the walmart entrance, A guy stops me and says "hey how do you get your car to do that?" and he points at my exhaust, and im like... bad paint job? my chrome is falling off? So a girl walking next to him says "hes talking about the sparks coming out of your tailpipe" and im like HUH? sparks?... So i just go "oh, its a diesel" and walk away.

Freaked me out because i thought that it was demolishing itself before i remembered that i let it idle for like forever. and maybie my muffler is falling apart. cool sparks anyone else?
Your burning up your engine and pushing it to hard. This 240D will have ashort life span if you don't knock this off! It might be too late already. Sparks coming out the tailpipe is hot metal fragments finding their way out of your motor.

If you really want to destroy it and put it into it's grave, keep driving it this way!
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Old 04-15-2008, 02:41 PM
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Poor Cervan.....he's as misunderstood as Trucky. I for one, like him.

I wouldn't do it to my car - but by golly, it's a free country. I won't point out the hypocrisy in his railing against WVO users though. Ooops, or did I?
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Old 04-15-2008, 03:22 PM
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Originally Posted by Knightrider966 View Post
Sparks coming out the tailpipe is hot metal fragments finding their way out of your motor.
I doubt it. It's soot in the exhaust burning off... a "chimney fire".

I've had that on VW diesels. I once bought an old neglected jetta diesel that had a bad stumble and smoked badly. The PO said he "always kept the revs below 2500 because diesel rev low". I figured it just needed some diesel purge and a hard run.

Out on the highway, at night. Both fuel lines in a 2l pop bottle filled with diesel purge. I took an uphhill onramp onto the highway, and wrung it out to 4500 rpms under load. Halfway up the hill, I could see little sparks. By the time I got to the top, there were embers floating around behind me.

Over years, the soot just builds up in the exhaust. If it never gets a hot run, it just stays there. If someone gives it an "italian tuneup", the EGT will spike enough to light up the soot just like a chimney fire.

FWIW, I bet idling for 45+ minutes could leave a fair bit of soot in the exhaust.
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Old 04-15-2008, 03:25 PM
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Some of the reason older rigs idled was to run auxillary equipment, ie refrigeration. I am sure there are other reasons and cost of diesel and pollution are probably other reasons. I think most of the refrigeration trailer now have a smaller egnine to run the A/C on them.
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Old 04-15-2008, 03:28 PM
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Your IP does not need extra lubrication.

That said if you really have the urge to waste money use 2 stroke oil.

Also. the sparks were almost certainly from the gasoline. He routinely over rev's the engine for no apparent reason.
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