coasting

[Hockey4mnhs]

i cant engine off coast b/c i have a auto. so lately ive been coasting down hills in N. Coast longer and go faster but i read a while back that some cars i think hodas shut off the injectors over a serton speed if there is not throtle applied. Is this really, if anyone knows please help

[omgwtfbyobbq]

If it's idling the injectors have to be on. What you're talking about only happens in gear. If the coolant is warm enough and rpm above some point (like 1500rpm) the injectors won't fire when you let off the gas and coast until the transmission gets to whatever the cutoff is (in this case 1500rpm), after which they start firing again. On some cars, they don't completely turn off, and will sporadically dump fuel into the catalytic converter to keep it's temperature up, but if you want to coast in N with the engine on, you should be o.k.

[Peakster]

Originally Posted by Hockey4mnhs

i cant engine off coast b/c i have a auto.

Can't you put the car in "N", shut off the engine, and then key start the engine when you're done the coast? That's what I was doing in the Silverado and Intrepid.

[kickflipjr]

Originally Posted by Peakster

Can't you put the car in "N", shut off the engine, and then key start the engine when you're done the coast? That's what I was doing in the Silverado and Intrepid.

This is what I did in my previous car, but it is so much easier to just bump start with a stickshift.

[Hot Georgia]

I shift to N in my '04 CVT HCH for about 7-10 miles of my 50 miles to work or back home. In the summer I switch to engine off coasting in those segments.

The reason I don't do the engine off in the winter is to prevent possible radiator stress for extreme, rapid heating/cooling expansion.

We also have a 2001 Grand Caravan which I'd love to roll in N. But I can not...the injectors stay on but when I need to go back to D the transition is very rough and jerky. Rev matching makes no difference.

[basjoos]

Originally Posted by Hot Georgia

The reason I don't do the engine off in the winter is to prevent possible radiator stress for extreme, rapid heating/cooling expansion.

If you have a grill block installed (with the reduced air flow that it produces), rapid radiator cooling is much less of a problem.

[Hockey4mnhs]

isnt it bad in a auto to engine off coast because of sum bering not being lubricated? so thats y i leave the car on so it stays lubricated

[repete86]

Originally Posted by Hockey4mnhs

isnt it bad in a auto to engine off coast because of sum bering not being lubricated? so thats y i leave the car on so it stays lubricated

There are almost no parts moving when the tranny's in neutral. I EOC in my '93 Accord all of the time and I haven't had any problems with my 125k mile transmission. If my tranny does go though, it would probably be a blessing. A 5 speed will do wonders for my mileage.

[bzipitidoo]

What is the use of neutral if the car can't be towed? What else is neutral for?! Pretty sorry neutral if it isn't intended for more than such emergency uses as being pushed to the side of the road or winched onto a tow truck.

But, some cars should not be "toad towed" or "dinghy towed" (all 4 wheels on the ground) as RV users call it. And yeah, a smaller percentage of automatics are towable. Here's some lists of cars that can be "toad": http://www.motorhomemagazine.com/techtalk/

[omgwtfbyobbq]

I don't think we would see an absolute melt down from EOCs since the output shaft bearing thingys aren't w/o lube for very long, but if you google you'll see reports of the output shaft being welded to the case after an RV owner decided to tow the wrong vehicle w/o unhooking the axles. The fluid's present, but at the bottom of the pan, so it's not much help to the output shaft about six inches above it. But.... There's still some fluid on after the engine's shut off, and it'll take some time to leave the bearings totally dry, but wear rates do likely increase, with the increase corresponding to the time the engine's off... It's a YMMV situation, and depends on the oil, tranny, and coast times/speed. I don't think the tranny will blow, but it may only last 200k miles instead of 350k miles, or whatnot.