Last weekend I was parking my car on a steep upward sloping street at a friends place (the grade/slope was about 15-20 % - my guess). Car was in D5 and moving forward. When car reached in a desired position along the curb, I pressed break to stop it. Then I released the break, car is still in D5, and it started rolling back on the slope as though it was in neutral.

I was surprised as I always thought that automatic car is not supposed to do that. Next day I tried to replicate the problem on some other streets (relatively mild slope) but it did not happen. I was curious so I went back to my friends place and checked again - yes car did it again.

So car rolls back (not skidding), wheels move as if it is in neutral on steep slopes while in D-5.

Am I missing something? Is this normal ?
Or is this some sort of transmission failure? (transmission otherwise works fine).

It is a 2000 TL with 40,000 miles. I bought it a year ago in a private sale.

 

that is normal, every car will do that if the slope is greater than the force of the engines idle.
oh and before you park on a hill you should apply the parking brake, take your foot off the brake (if the parking brake holds) then shift to park

 

Had a 97 BMW 528i that didn't roll back even on the hills of San Francisco. Don't know how the Germans did it but it was definitely nice.

 

does rolling back hurt the tranny or anything because mine does that all the time if its steep enough. i feel like i should be engaging the clutch or something

 

SOme cares have "hill holders"...bmw's I know do as a lot of the lux german cars do..i'm kind of surprised the TL doesn't...but then again, it doesn't have a lot of other "simple" things that it should..but that's for another thread! :toothless

 

This was done on purpose as I understand, to help in fuel economy. Even while in gear, it somewhat applies a form of a clutch until the torque converter gets up to speed and moves the car forward.

You'll also find another strange thing- while stopped at level pavement (if your A/C is on) and foot slightly on the brake, you'll find your car start to unexpectedly surge forward. This would surprise mainly AT only drivers since they have their foot rested on the brake while stopped. On the same principle, if the A/C compressor is on, the tranny tries to compensate for the slight power drag and move the idle up slightly. But a car with this much power, your foot should be firmly on the brakes anyway.

 

This happens to me ALL THE TIME when I'm in San Francisco. When I first noticed it, I immediately wanted to test out how far & fast it'll allow me to roll back.

My GF thought I was nuts since I purposely drove up a HUGE hill (lumbard I think), waited till I was the only 1 on the block, released the brakes so I can roll back, then all of a sudden BAM! Engine shuts off and I lost my power brake! Mind you I was still rolling down when I popped it in neutral & started the engine, but by then I've already rolled down quite a bit.

I doubt it was distance, since I can roll down the hill pretty far without stalling, but it's the RATE of decent that you should worry about. Once you go too fast backwards in D5, the engine will shut down AND you'll be going even faster since you just lost power. So...if someone is not strong enough to stop the car without power brakes, then they'll definitely be OWNED in a matter of seconds.

Now...some of you guys are probably thinking...WTF would you EVER want to roll back in D5?! Well...try parallel parking uphill!

 

hahahahaha sounds like something i would try (if we had hills big enough around here

 

Correct...
i do this all the time..
i never just slam into park without the food brake...

 

oops foot brake