Re: bmw-digest V9 #525

["Jonathan Lukens" <jlukens@xxxxxxx>]

>Date: Mon, 16 Nov 1998 19:27:22 -0500
>From: "Wilks, Murray" <MWilks@domain.elided>
>Subject: How Long Can I REALLY Let Car Warm Up Before Driving
>
>My owner manual says NOT to run the engine a long time at idle just to
>warm up the car. I think it suggests a max of 30 seconds or something
>low like that. Obviously, no-one at BMW has had to wake up to a frigid
>car in frosty Calgary.
>
>Does the BMW caution against long idling (to warm up the car) arise more
>from an environmental concern, or is there a valid and important
>MECHANICAL reason for this?
>
>Murray
>97 318i

Conventional wisdom would say to warm up a car at idle for extended periods
of time is alright, but really it just creates moisture, which will damage
engine parts -- that why you see droplets coming out of tailpipes.

I've observed on the digest the recommendation that one just warm up or idle
enough to gain normal oil pressure:  20 seconds at best.

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