my 04 auto tl has 99k miles on her. ive always changed the fluids (oil, trans fluid, brake, power steering etc) at proper intervals. but lately when i have my air conditioning on, the car feels like it doesnt want to move.

for example, if im taking off from a stop light and the car shifts to 2nd gear and i give her some extra gas to take the rpms to about 4k, it really feels like forever until it gets there. if the a/c is off and i do the same thing, i get pulled back in my seat a tiny bit but the car drives like its supposed to.

also, when the air conditioning is on, the rpms dont climb smoothly when hitting the gas harder then normal but not WOT....if that makes sense. usually between 2.5k and 4k. it feels like the rpms slow down, then speed up, then slow down and so on. does that make sense? this doesnt happen when the a/c is off

i changed the spark plugs 5k miles ago. ive seafoamed the gas, intake, and engine oil 3 times since 70k miles.

 

Many cars disengage the AC compressor while at WOT. This is for safety purpose as someone may need all the power for a passing manoeuvre with oncoming traffic. I suspect the TL does the same altough you won't notice it as much as with a less powerful 4 cyl engine.

There's probably something wrong with your AC compressor. It may be harder than usual to spin so there's less power available for acceleration. However, I found it very strange that your RPM wiggles like you mentioned. May be the transmission is caught over the on/off transition of the overdrive position because of the higher than usual load of the compressor.

I would definitely have your AC system checked.

Googd luck.

Carl

 

bump

 

I've been meaning to try this out on my vehicles but it may improve efficiency on the A/C system lowering the load on the motor ?

https://www.youtube.com/watch?v=r_em9lm69HQ

 

The a/c does take a lot out of the cars power. I am not sure what it causing your RPM issues but i do know the compressor does cycle on and off so that could be some of the issue.

 

You might take a video of you starting out to show your RPM changes. However, a significant drop in power is normal when the AC is on.