Weird transmission noise

So I am still getting used to my 2019 Tacoma in that I don't even have 3,000 miles on it yet. So I pulled up on a real steep inclined railroad crossing where there are railroad tracks running parallel to the road. On the side of this intersection where the road is there is a stoplight with barely enough space for one car when the light is red. When I pulled up there was a car there so I had to stop on the upward incline side till the light changed and a car pulled up behind me. When the light turned green I took my foot off the brake and moved over toward the gas and the truck rolled back as if it where in neutral. It felt like it was going to hit the car behind me so I gave it gas and it made a odd grinding noise and then started pulling forward and drove over the railroad hump and on down the road. I've been at this intersection in my prior truck many times in exactly this same situation and as with most other automatic transmissions that Ive owned before they will only roll back slightly but my new truck felt like it would just keep rolling. Does this seem normal because it didn't seem normal to me? Thanks

 

It may have engaged Hill Start Assist which makes noise.

 

Really? Whats that shakerhood...BTW Nice Foxbody!

 

Go on a steep hill and just let the truck roll backwards and listen to the brakes slam on by themselves. Hill start assist is my guess

 

Wow....this truck is like a "smart truck" and my F150 was like a "dumb truck"....LOL. So I could test this feature by pulling up on a hill that is say not in traffic and letting off the brake huh? Most vehicles ive owned before I think the auto trans just kept it from rolling back with no involvement from the brakes.

 

TY, I have owned it for 21 years. The HSA uses ABS to engage it if I'm not mistaken.

 

I've had he same issue. Sounds like your dragging chains. Doesn't seem normal to me either. Could be HSA I guess. I'm asking the dealership next visit.

 

I agree Joe it doesn't sound or seem natural to me either I too am going to ask the dealership at my first oil change...I also want to ask about my idle....the truck idles so dag gum high....initially it idles at a touch under 1200rpm....its been cold since I have owned it....after several minutes it drops to 1000rpm...then after it has ran for awhile is idles between 400-500rpm which for me is then too low b/c I can feel the engine vibration in the cab....I almost worry when I put it in gear at 1100rpm that I might break something.