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Discussion Starter · #1 ·
I started my 300SD and planned to let it run for several minutes because it sat for about a week. I forgot that it was idling and let it idle by mistake for close to three hours. Fortunately, the temperature gauge was reading only 85 degrees C when I finally realized that the engine was running and just before I shut if off. The engine was merely warm, just like after a 1/2 hour high speed ride. I took the car around the block to see if anything felt funny. Nothing seems to be wrong. Should I worry that I may have damaged something? Like turbo, for example? I heard that truckers let their diesels idle for hours, even days. I hope this 3 hour idle did no harm to this engine. This was in the evening, so temperature outside was around 50 degrees.
 

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1985 500 SEC, 2005 E320
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na. don't worry about it. Sometimes when stuck in traffic, we all idle for long periods. These motors are tough. You're fine.
 

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Depends on the day!
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If the oil is anywhere near it's replacement window I'd go ahead and change it.


Jonathan
 

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indeed. thats one thing i always stress to people. milage on the car doesn't exactly depict the number of rotations the engine as done within those miles. hell, someone who commutes in thick traffic for long distances could potentially have the equivalent to 6000 miles by comparison to someone who commutes the same distance on a open, trafic-free higway at 3000 miles.
 

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Discussion Starter · #5 ·
Very true and those miles are a lot harder on the engine too. Also on the cooling system.
 

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Diesels are not gas engines, slow running is their forte. Gas engines on the other hand like to foul their plugs and dilute their oil. A diesels crankcase oil is similar to it's fuel! Diesels have no plugs to foul - glow plugs don't count. In fact if you live with a diesel in Alaska you will soon find that you let it run all night pulled into a snowbank or it won't start.
 

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Discussion Starter · #7 ·
Looks like I have nothing to worry about as the coolant temperature stayed in the normal range.
 

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NordRhein said:
Diesels are not gas engines, slow running is their forte. Gas engines on the other hand like to foul their plugs and dilute their oil. A diesels crankcase oil is similar to it's fuel! Diesels have no plugs to foul - glow plugs don't count. In fact if you live with a diesel in Alaska you will soon find that you let it run all night pulled into a snowbank or it won't start.
Do you have a block heater? How about adding a gallon of gas to a full tank of diesel?

Although diesels do OK idleing they are better off being used under some load.


Jonathan
 

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i'm from alaska. i've never had a problem with startup with diesels. that's what glow plugs are for. anyhoo, i think the point wasn't so much the differences in petrol or diesel, but more so the wear and tear from extended opperating of the friction components. i had a much worse time in fairbanks starting my 3.0L petrol turbo Z car than starting the UD diesel box truck for work.
 

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Well glow plugs are great but if the car isn't in good tune (valves) you don't have much of a second chance if any before the battery is dead because of the bitter cold. Running all night doesn't hurt them a bit and with it running there's no issue. As for wear once an engine is up to operating temperature wear goes practically to zero. That's why manufacturers can run a test engine on a stand and go a million miles and still be in specs. Now cold starts - that's murder on an engine.
 
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