Here we go again... EOC & automatics

[Oval_Overload]

Ok, so we have already established that Engine Off Coasting in an automatic means that your transmission fluid pump isn't running, and therefore the tranny is oil-starved. That means if your running one of these lovely AX4S transmissions (Windstar, pre 2005 OHV Tauruii and Sables) like Sean and I, it will eat a clutch pack, implode, and create a black hole that swallows all known life in the universe.

Anywaaaaay...
People keep telling me Minnesota is flat. I fail to believe them. The hills in Stillwater are so ridiculous that we have staircases connecting neighborhoods, and I can coast halfway across town if the traffic is light.
A friend of mine lives at the top of a long (1.7 mile) hill, and I always use first gear compression braking on the way down. On my down today, I realized that in first gear with the throttle closed, the Torque Converter is still locked, the alternator is still running, the vacuum system is still pulling, and the transmission fluid pump still runs

So I killed the ignition. At the bottom of the hill I turned it back on, and everything functioned normally the whole time! The engine cranked over smoothly on the cars momentum, no problems whatsoever. I never had to use the brake or the throttle for those 1.7 miles.

Oh, and I didn't have to rev match because the car was in gear the whole time.

So is there anything I need to know before I go ahead and install a kill switch?

[Big Dave]

Why doncha just click it into neutral?

[MetroMPG]

Are you sure the engine isn't in fuel-cut mode in that situation already?

[Oval_Overload]

Originally Posted by Big Dave

Why doncha just click it into neutral?

Compression braking

[Oval_Overload]

Originally Posted by MetroMPG

Are you sure the engine isn't in fuel-cut mode in that situation already?

I'm not sure, but i could hear/feel it start when i turned the ignition on. If it were in fuel-cut mode, would it sound the same as 'off'?

[TestDrive]

Don't we need to distinguish between Engine Off Coast in Neutral (EOC-N) and Engine Off Coast in Gear (EOC-G)?

[Oval_Overload]

Yes. I'm talking about EOC-G for the reasons stated in the first post.

[Oval_Overload]

SHOZ on TCCA answered my question, do Taurii have fuel-cut mode?

"Yes they do. There is a strategy called Coasting Fuel Shut Off. Pretty lame with OEM tuning. I adjust this to be a lot more aggressive in my tuning."

So, yeah, kinda what I expected in a sedan rated 19 mpg city.

[RH77]

The Taurus has an odd behavior that you may have noticed...

Shifting to Neutral while coasting, increases RPM to potentially match the gear re-engagement. Same for downshifting from OD to D -- it actually speeds up and offers little compression.

I have some concerns about iGEO-CIA (In-Gear Engine Off Coasting in Automatics). [Acronyms are fun!]

The torque converter is locked with no fluid pressure to the remaining components. I would highly recommend flipping to neutral and use the starter. It's a lot easier to replace than a tranny.

-Rick

[Oval_Overload]

Why wouldn't there be fluid pressure? In D and 1, the entire drive-line is locked in gear and rotating due to the car descending the hill. In this case, the tranny should be getting more pressure than it would in normal driving because the crankshaft turns at 2500 rpm in 'D', rather than 1000 rpm if i were to descend the hills in 'O/D' with the hydraulic brakes.

I'm assuming the tranny pump is driven off the input shaft, but please, correct me if I'm wrong about any of this.