OsK

iTrader: (2)

Hear me out; I know it doesn't make any sense, but it's definitely true for my car

If I drive with the A/C on, the upshifts and downshifts are smooth and don't give the jerky motion a lot of us experience coming to a stop, especially with the Type S.

Once I turn my A/C off, everything changes. The downshifts are more noticeable/engine braking, when coming to a stop, regardless of incline (Grade Logic) and upshifts are a little more rough.

Could anyone explain this? Is my Serpentine Belt tension a little off, or just belts in general? I'm thinking once I turn my A/C on and there's load on the drive belt (serp), it triggers something.

Any thoughts appreciated....

paperboy42190

iTrader: (7)

thats weird, I cant say I've noticed any difference with or without AC

Turbonut

iTrader: (1)

Probably just the additional load placed on the engine when the compressor is engaged.

ntmera

Simply just the fact that the A/C being engaged takes some of the momentum between gear shifts. It'll also help you engine brake.

02tlnate

That's strange to hear I have a 02 tl-s and mine is the complete opposite. Rougher with a/c on otherwise smooth without it. Although we have different cars,I'd assume the same engine set up in a way

NBP04TL4ME

My 08 TL-S MT is a little rougher as well. It requires a little more finesse when shifting gears.

OsK

iTrader: (2)

Yeah, but why would it be "smoother"? I swear it makes no sense but it's pissing me off that when I come to a stop, I can see my tach bouncing up and downshifting perfectly without any bucking sensation, but once I turn my AC off, it's back.....god.....

mau108

I find with the A/C engaged the revs drop quicker between shifts..

truonghthe

OP did you get the AT (if your car is AT) services like 3x3 and pressure switches? The only explanation I can think of is when you turn on the A/C, clutch engage cause a smallpower loss therefore the jerk motion is less noticeable or your description as "smoother".

OsK

iTrader: (2)

I've only done 1 drain and fill with OEM fluid. No pressure switches, because we have the RL tranny, and I haven't heard of stories of them failing. Wasn't the whole premise of 3rd/4th pressure switches for the 04-06 models?

Hmm, yeah thanks for the explanation; I mean when I say smooth I mean It's a big difference. I don't feel it downshift or upshift at all.

truonghthe

yes I did 4x3 prior to changing the switches and some time it does hard shifting from 3rd to second specially when you slow down for a red light.

Rip Flair

Sounds weird. i would agree with what truonghthe said tho.

ntmera

Just did all 3 motor mounts, front and side were 100% toast, rear was fine. Shifts are not noticeably different anymore whether A/C is on or off.

OsK

iTrader: (2)

My F+S engine mounts were replaced couple months ago as well....still happens for me. I did another 1x3 tranny fluid change and it's a little smoother. we'll see.

truonghthe

do 3x3, I did 5x3 just to make sure i get all the old fluid out then I change the pressure switches and now it shift much better than the new TLX 9spd AT.