Driving in neutral bad for engine?

[GasSavers_jkandell]

I do a lot of coasting in neutral. This has me a bit worried:
"An idling engine isn't operating at its peak temperature, which means that fuel doesn't undergo complete combustion. This leaves fuel residues that can condense on cylinder walls, where they can contaminate oil and damage parts of the engine. For example, fuel residues are often deposited on spark plugs. As you spend more time idling, the average temperature of the spark plug drops. This makes the plug get dirty more quickly, which can increase fuel consumption by 4 to 5 percent. Excessive idling also lets water condense in the vehicle's exhaust. This can lead to corrosion and reduce the life of the exhaust system."
idling-myths

[Hockey4mnhs]

eoc is said to be bad for a auto tranny but other then that i havent heard much about outer things

[jwxr7]

you could turn off the engine instead of idling .

[Fourthbean]

I am no expert on engines, but have heard of the problems you are talking about. Though excess idling I imagine would be ALOT of idling. Not idling for a mile every 2 miles. I also would think that if you idled for a mile and then ran your engine somewhat hard afterwards you would blow out what was deposited during the idle. On the other hand if you were idling for hours I think it would be a different story.

That is my take on it. I am sure some more knowledgeble folks are typing up a reply right now .

[Bill in Houston]

The paragraph you quoted was written to encourage Canadian drivers not to idle to warm up their stone cold cars. Completely different from when you and I idle in neutral with a fully warmed-up engine...

[rvanengen]

Originally Posted by jkandell

I do a lot of coasting in neutral. This has me a bit worried:
"An idling engine isn't operating at its peak temperature, which means that fuel doesn't undergo complete combustion. This leaves fuel residues that can condense on cylinder walls, where they can contaminate oil and damage parts of the engine. For example, fuel residues are often deposited on spark plugs. As you spend more time idling, the average temperature of the spark plug drops. This makes the plug get dirty more quickly, which can increase fuel consumption by 4 to 5 percent. Excessive idling also lets water condense in the vehicle's exhaust. This can lead to corrosion and reduce the life of the exhaust system."
idling-myths

An idling engine should be running at NORMAL operating temperatures within a few minutes. If this weren't so, there are a LOT of police cars that would die prematurely. I just recently got rid of a used police car I picked up on ebay, and I am sure that the motor had a LOT of "donut miles" on it. Main problem that car had was just normal police pursuit and operational wear.

[VetteOwner]

driving in neutral is not bad for anything but if the engine is off coasting down hills then your goinna run into serious tranny problems

[cfg83]

jkandell -

Originally Posted by jkandell

I do a lot of coasting in neutral. This has me a bit worried:
"An idling engine isn't operating at its peak temperature, which means that fuel doesn't undergo complete combustion. This leaves fuel residues that can condense on cylinder walls, where they can contaminate oil and damage parts of the engine. For example, fuel residues are often deposited on spark plugs. As you spend more time idling, the average temperature of the spark plug drops. This makes the plug get dirty more quickly, which can increase fuel consumption by 4 to 5 percent. Excessive idling also lets water condense in the vehicle's exhaust. This can lead to corrosion and reduce the life of the exhaust system."
idling-myths

Welllllll, for Saturns, leaving the car in idle causes the engine to overheat , so I am guessing that combustion isn't a problem.

It would be interesting to know the "average temperature" of a spark plug, however.

I don't worry about coasting in neutral, but I do assume that I am wearing out my clutch faster.

CarloSW2

[slurp812]

Originally Posted by jkandell

I do a lot of coasting in neutral. This has me a bit worried:
"An idling engine isn't operating at its peak temperature, which means that fuel doesn't undergo complete combustion. This leaves fuel residues that can condense on cylinder walls, where they can contaminate oil and damage parts of the engine. For example, fuel residues are often deposited on spark plugs. As you spend more time idling, the average temperature of the spark plug drops. This makes the plug get dirty more quickly, which can increase fuel consumption by 4 to 5 percent. Excessive idling also lets water condense in the vehicle's exhaust. This can lead to corrosion and reduce the life of the exhaust system."
idling-myths

I blasted my car to 6000 rpm yesterday twice! but then I did about a mile EOC. But the reason I did that was because I thought I felt the car sputter when it wasnt warmed up the other day leaving a parking lot. I used to tell people cars need to be DRIVEN, not babied to death. Give that thing some gas at least once in a while. But I am leaning the other way now, in the name of saving $$$ and helping the planet just a bit. So I will still stomp it at least once per tank....

[JanGeo]

A rev is ok as it tends to loosen up the engine a little works some oil to the top of the pistons and breaks loose any carbon in the combustion chamber - I usually rev it once a trip but not flooring it just a quick rev in first gear with light throttle.