Anything inherently bad about idling?

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Recent thread on Hemi engines would point to idling as being bad for the cams, with less oil available for cam lubrication. YMMV on that thread. As well, extended idling in cold temperatures with newer DPF equipped diesels can be bad with soot buildup, resulting in frequent regens. Which may cause the engines to go into limp mode. Had 1st hand experience with that in a large fleet.
 

CT8

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Originally Posted by Bud
Originally Posted by CT8
Why are you wondering?
Why, is there something wrong with being curious?
I am curious why are we asking the question .
 

CT8

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Originally Posted by Danno
Recent thread on Hemi engines would point to idling as being bad for the cams, with less oil available for cam lubrication. YMMV on that thread. As well, extended idling in cold temperatures with newer DPF equipped diesels can be bad with soot buildup, resulting in frequent regens. Which may cause the engines to go into limp mode. Had 1st hand experience with that in a large fleet.
The idling is bad started before the diesel emissions problems. I would guess it is propaganda to save fuel as is the XW-20 wt oil push..
 
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Originally Posted by Avery4
Hello everyone, I am wondering if there is any reason why letting a car engine idle for extended periods of time would inherently be bad for it. I know that whenever the engine is running everything is inherently wearing out and with all else being equal the more hours on it the more frequently it will require maintenance, but is there anything worse about idling all day than, say, driving down the highway all day? For the purpose of this question let's assume that the vehicle in question has a well maintained and correctly functioning modern fuel injected engine, a good cooling system that keeps the engine's temp in a normal range at all times, and no significant design flaws.
Simple Answer. NO. Wasting Gas thats about it. Now if you start your car cold let it run for 2 seconds then shut it off. You do that? Day after Day? That is bad. Otherwise? Idle all day long if you want. All you will be doing is wasting is Gas.
 
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Let's just say there are many good reasons why extensive idling is considered "severe service" in every owner's manual I have ever seen. Extensive idling will not blow up your engine but it's not good for it either. I shut off my engine if I expect to be idling longer than about 30 seconds -- it's easy to anticipate long stops if you drive the same route every day.
 
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Originally Posted by Avery4
Originally Posted by Chris142
... I do believe that spinning parts are lubricated better at higher speeds.
That is likely the case, but the load on the spinning parts is also higher at higher speeds so the parts would need more lubrication than when under a very low load idling.
Valve-train parts, especially the tip of the cams, may be under greater stress at idle than at a moderate speed. That's because at moderate speeds, inertia partially overcomes the loading due to the spring force. (It can drop to zero at very high speeds, but then you have worse problems.)
 
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Power went out one night and my wife slept in her car for 7 hours and engine was idling with the A/C running. I doubt it would shorten engine life if it was done on a weekly basis.
 
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Clarification: By "It" in the last sentence (in parentheses) of my post of a 2+ hours ago, I meant the net stress, that due to spring force minus reduction due to inertia at maximum valve opening. Zero difference would be valve float.
 
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It wastes gas, pollutes, etc, and creates engine wear, wear that could have moved the vehicle down the road logging miles traveled.
 
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I've idled many, especially during grad school when work and home and school were all an hour apart, and group sessions and all that. Half of my masters was earned in my car. In each I learned consumption per hour with HVAC on. Any issues I had couldn't be separated from other cases just because I was only one example. But my great grandmothers ‘57 Chevy required a full rebuild at 80,000 miles, well overdue. The cylinder wear was amazing, bored in over 40. Cylinder ridge and out-of-round was huge. Oil starvation was the theory we had as to why it was totally shot when we got it at 72,000. They idle at 450 rpm or so, low psi at those speeds - pump was turning at some lower-than-crank speed from a gear off the cam. I'm not a big fan of idling them - it's a waste of enviro and my money, but I'll say this, the 2.7L ecob. Ford just sips fumes at idle, whereas the toyota V6 in the garage is a thirsty pig at idle. In fact, that 2.7 was as thrifty at idle as the 2.4L NA Volvo's I've had, which I'm pretty sure could idle for an hour if you drew a picture of gasoline and set it on the dashboard. Low oil pressure, Ford Tauri in the 80s were known for car b que from extended idling, fuel dilution - probably varies per model.
 
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My neighbor across the street cracks the garage open and idles his ten year old accord for hours it seems. Why? I dont know. I've thought about asking him what his maintenance schedule is like.
 
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