idling with AC on
 

I used to think idling (maybe more than 5 min) was bad for engine, but
then I read elsewhere that it's no worse than driving. I think i read
that idling with AC on puts alot of stress on the engine. Is this
true? Should I turn off the AC if idling for more than 5 minutes? I
have a dodge truck, and ideally I could sit in it for 15 minures,
idling, with AC on...

Also, in the winter, is idling with heat on any problem?

Idling for a given amount of time is generally no worse than driving for the same time, except that you will be wearing out the engine without getting anywhere. The biggest problem with idling with the AC on is overheating. The biggest problem with idling in the winter is fouled spark plugs and contaminated oil because the engine will not get as warm as it will when driving.

mac wrote:
>
> I used to think idling (maybe more than 5 min) was bad for engine, but
> then I read elsewhere that it's no worse than driving. I think i read
> that idling with AC on puts alot of stress on the engine. Is this
> true? Should I turn off the AC if idling for more than 5 minutes? I
> have a dodge truck, and ideally I could sit in it for 15 minures,
> idling, with AC on...
>
> Also, in the winter, is idling with heat on any problem?

--
Mike Walsh
West Palm Beach, Florida, U.S.A.

It's interesting that in older non-computerized cars, the A/C would *lower*
the idle rpm, thus conceivably *saving* gas at idle!
In newer cars, the A/C bumps up the idle speed, indeed costing more gas.
'pyooters, donchaknow....

Idling in winter w/ the heaters on can conceivably lower engine temp.
Ackshooly does help if the engine is *over*heating.

What gets me is the new thing of driving off w/o warming up the car at all,
as per, sposedly, mfr's instructions!
----------------------------
Mr. P.V.'d
formerly Droll Troll
"mac" > wrote in message
oups.com...
>I used to think idling (maybe more than 5 min) was bad for engine, but
> then I read elsewhere that it's no worse than driving. I think i read
> that idling with AC on puts alot of stress on the engine. Is this
> true? Should I turn off the AC if idling for more than 5 minutes? I
> have a dodge truck, and ideally I could sit in it for 15 minures,
> idling, with AC on...
>
> Also, in the winter, is idling with heat on any problem?
>

Mike Walsh wrote:
> The biggest problem with idling with the AC on is overheating.

This is not necessarily true. On my car, turning the A/C on while
idling forces one of the engine fans on, keeping the engine cooler.

mac wrote:
>
> I used to think idling (maybe more than 5 min) was bad for engine, but
> then I read elsewhere that it's no worse than driving. I think i read
> that idling with AC on puts alot of stress on the engine. Is this
> true? Should I turn off the AC if idling for more than 5 minutes? I
> have a dodge truck, and ideally I could sit in it for 15 minures,
> idling, with AC on...
>
> Also, in the winter, is idling with heat on any problem?

When I lived in West Texas the company bought me a brand new
Chevy 4dr truck. We (me & crew) used to leave the truck running in
the summer for the A/C and in the winter for the heat.
The engine lasted 9 months before it wore out. The next guy that
got it had it for 1 year before it needed a new engine.

On Thu, 28 Jul 2005 00:41:37 GMT, "« Paul »" <" « Paul
> wrote:

>mac wrote:
>>
>> I used to think idling (maybe more than 5 min) was bad for engine, but
>> then I read elsewhere that it's no worse than driving. I think i read
>> that idling with AC on puts alot of stress on the engine. Is this
>> true? Should I turn off the AC if idling for more than 5 minutes? I
>> have a dodge truck, and ideally I could sit in it for 15 minures,
>> idling, with AC on...
>>
>> Also, in the winter, is idling with heat on any problem?
>
>When I lived in West Texas the company bought me a brand new
>Chevy 4dr truck. We (me & crew) used to leave the truck running in
>the summer for the A/C and in the winter for the heat.
>The engine lasted 9 months before it wore out. The next guy that
>got it had it for 1 year before it needed a new engine.

Police all over the country do the same thing and their engines don't
wear out in a year. Sounds like that truck had a problem but it had
nothing to do with letting it idle with the AC or heater on.

"mac" > writes in article .com> dated 27 Jul 2005 09:11:58 -0700:
>I used to think idling (maybe more than 5 min) was bad for engine, but
>then I read elsewhere that it's no worse than driving. I think i read
>that idling with AC on puts alot of stress on the engine. Is this
>true? Should I turn off the AC if idling for more than 5 minutes? I
>have a dodge truck, and ideally I could sit in it for 15 minures,
>idling, with AC on...

Idling with the AC on puts stress on the AC due to reduced airflow over the
condenser, causing higher temperature and pressure and more work for the
compressor. Especially if your engine fan is belt-driven (so it runs slower
at low engine RPM).

The engine itself should handle it fine.

>Also, in the winter, is idling with heat on any problem?

No, not any worse than driving.

-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.