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Quiet @ 40mph??? .. (another noob question)

832 Views 4 Replies 4 Participants Last post by  pabrannan
Ok.. so when coming off the interstate and coasting.. the motor is QUIET until it dips under 40mph.. is it cutting fuel? or just lowering the pressure in the rails? I have heard rumor that there is some sort of "whisper" mode that can be had at idle to keep the noise down.

I ask because I have remote start and a short drive to work.. I would love to be able to let it sit in the driveway and warm up before driving, but I am trying to be considerate of my neighbors (and dont want to piss em off @ 6am with a clackety-clackety PSD for 15mins).

I am sure there is someone here that knows what I am talking about.

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When you just lift off the go-pedal and don't touch the brake, the torque converter clutch stays locked until speed drops below about 40 mph, and the injectors effectively shut off (gassers do this on decel, too, BTW), hence the quiet. When the TCC unlocks, engine speed drops back to idle and the injectors start firing again to keep the engine running. /ubbthreads/images/graemlins/smile.gif

There really isn't a "whisper" mode on the 7.3L. They just make diesel sounds.

And there's really no reason to warm-up the truck for 15 minutes in San Diego just about any time of year... at 6ayem, you won't have any sun load to heat up the interior, either. One of the benefits of living in a coastal temperate zone. All that warm-up cycle is doing is wasting fuel, IMO. You could accomplish all the warming up you need to do by driving sedately out of the subdivision/apt. complex to the main drag.

I like San Diego -- we sometimes stay there when we're testing about 90 minutes east of there out in the desert. Neat place, but not really any hot or cold issues.
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