Automatic Transsmision ..

[Ndx]

Topic is related to this but not exactly
https://bobistheoilguy.com/forums/threads/knocking-rattling.94655/

So i made some test As i said in previous topic when i drive 60 I slow down .. Car will down shift one gear ... and I Acceelerate i can hear rattling/grinding ..( i can feel a little on gas pedal )

it happens 3>4 and 2>3 too So Im driving ... slowing, car down shifts and I accelerate there is noise ...

Car is equipped with shiftronic .. so i went for a ride .. i engaged gear 3. slowed accelerated no noise ... i tried same thing on 2nd.... same no noise ..

so do u think my transmission maybe messed up ? But what i don't understand - how come is doing this on automatic ? and not on Shiftronic ? maybe because on shiftronic im staying with in the Gear .. and clutches are not slipping to go to 4th ?

 

[parimento1]

I have had the same thing in my car (97 Toy Avalon) since the day it was new. I have heard other Toyota cars with it as well. In 12 years and 140k miles it has not gone away and it has not gotten any worse. I think it is pinging due to the load in the higher gear. I wouldn't worry about it. Also, it has nothing to do with the transmission as mine was rebuilt last year and it still makes the same noises under the same circumstances.

 

[Ndx]

yeah i test droved same models same years none had it ... at its not normal for sure ..

if its not transmission related how come it works noise-less on manual mode ?

Thx anyways

 

[parimento1]

Just curious...what make of car is it? Mine does it, as with yours, under part throttle. Does it ever do it with full throttle?

 

[Ndx]

Mazda 3 2004 95Kkm on it ...
Umm ..i never tried full throttle... but more gas more noisy

im doing 80.. slowing it drops to 3rd i slow so its almost droping 2 but didn't and NOW i accelerate there is noise .. and gap i delivery power like slipping maybe 1-2 second

 

[parimento1]

same exact thing happens to mine it definitely drops power but after the rattling stops I get the power back. It is very odd, yet it has not caused any problems besides just being an odd noise. I too thought it was coming from the transmission- torque converter chatter. But even after the rebuild with a new converter it still does the same thing...so I guess the only thing left is an engine issue. I wonder if it is pinging and the engine is cutting power because the computer is detecting the knock and pulling timing. Would be interesting to look into it with a scan tool hooked up in real time. Let us know what you find.

 

[Ndx]

yeah car is back to dealer ... on next week ...they will work/replace transmission ..

if that was a ping ? shouldn't it happen always not only on drop in Automatic mode ?