I had a 96 3.3l Grand Voyager that did that on a cold start in
sub-freezing temps. It would run 4-5 mi. before it would drop into od.
My current 05 3.8l Grand Caravan does pretty much the same.
I always figured (rightly or wrongly) that it was a Chrysler trick to
speed engine warmup. Never noticed any ill effects from it. Never
noticed it happen above freezing, either.
Maybe someone with direct knowledge can enlighten us both.
On Tue, 11 Apr 2006 19:20:34 -0400, "Donald Gall"
My '05 Durango does the same, as did my trusty rusty '91 Pathfinder. I suspect
it's fairly standard behavior to get the autobox juices warmed up before
risking a galled bearing, but I suppose it could also be related to getting
the cats nice and toasty quicker...
This was brought up on either this or another newsgroup several months
back. I noted that both of my Ford Aerostars did the same. Some
self-proclaimed expert said overdrive engagement was not engine
temperature controlled, but it's been my experience that on many
vehicles there is NO O/D engagement until either engine or AT, not
sure which, reaches a minimum operating temperature.
Many vehicles delay engaging the overdrive until a certain temperature is
reached. You can Google a few terms like "overdrive temperature engagement"
and see a lot of info on it. On many such vehicles, the overdrive will
still engage even when cold IF you increase your spead high enough -- like
85 -- where engine rpm are getting a little too high for comfort.
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