mptlptr

Have any of you guys noticed that the car drives differently with the AC on (besides the obvious power loss)? I know when the AC is first turned on it makes sort of a clunk sound and you can feel the compressor clutch engage. However, I am noticing the same clunk sound when I'm accelerating and I can feel a slight but annoying hesitation. It usually happens between 2000-2500 RPM. It's as if the compressor is turning on/off. I've never had a car in which I could feel the AC "engage" while accelerating. Is this normal? I have a 6MT, but doubt it would be different for 5AT?

whatjones911

You feel the A/C compressor go on/off because it constantly goes on/off to help save gas. Most other cars, if you have the A/C on, the compressor is always on. But i have to say it is very annoying and noticeable to feel it go on and off. Acura should of done a better job of reducing the feel of the jerking when it goes on and off. Especially when I'm at a stop light the car would jerk foward when it goes on or off and the car would move so that i have to apply more pressure to the brakes when at a stoplight

Repecat

Interesting observation. I have had other cars where I felt the A/C cycling on and off, but those vehicles had far less power than the TL (120 to 160 BHP). In 19000 miles of driving the TL I have never felt the on/off of the compressor. In fact, that was one of the factors I considered before purchasing the TL.

gauravp123

I don't feel any jerking whatsoever, I only have 2900 miles on the car, 5.5 weeks old...what I do feel is the obvious decline in power/acceleration but no jerking etc

SouthernBoy

Virtually all cars cycle the A/C compressor on and off. However, the TL A/C unit will only cycle when set in the Auto mode. If you are using it in manual mode, the compressor stays on.

I have an '04 manual and the only time I find the A/C annoying when driving is between shifts. When the compressor is on, it robs a little torque and causes the engine RPMs to drop more quickly than when not in use. This affects my shift timing, so I have to alter the process. The reason is that we have relatively low torque engines in our TLs.

mptlptr

I'm pretty sure I'm in manual mode (I adjust the temperature and fan settings manually and have never hit the auto button) and I can feel the AC cycling.

Road Rage

I noticed some changes in the spark timing map when A/C is engaged (I do not care about the cycling "feel"). I wonder if this is done to help reduce the compressor parasitic power losses? If so, it is clever, as I do not believe the EPA emissiojns test loop requires the A/C to be engaged.

?

Adobeman

All of the many cars I have owned cycle the compressor. Without exception. That doesn't mean they all do.

Southern Boy - Are you sure about the manual mode thing? Seems like you would eventually reach a condition that would cause the compressor to disengage.

And, yes I do notice it kick in and out. Particularly when decelerating slowly to a stop while in gear (6MT). Compared to other smaller engined MTs I've owned the TL is pretty good. My old Saab felt like somebody hooked up a camper to it every time the AC comp kicked in. The TL feels nothing like that. They way I drive I only notice a slight loss in power.

yohan81718

manual mode for AC means pressing AC button to observe AC off or on...
if you don't see A/C off or on, you are still in auto mode for AC

SouthernBoy

Regarding my statement about the compressor running all the time when in the manual mode setting, certainly I could be in error with this. Here's what I am basing my observation on (bad me.. ended a sentence with a preposition).

Last year in South Carolina (summer time), I was using the A/C while my wife and I were going to dinner. My TL had been parked all day under a covered garage so there was no heat in the car caused by the sun. I was using the manual mode with the A/C on and the drive to the restaurant was maybe 40 minutes. I noticed that after about 20 minutes, the compressor had never cycled. So just for kicks, I raised the temperature setting a bit. I did this a few times until I had the temperature setting at 80 degrees. The compressor was still operating. So I lowered the temperature setting to 72 and selected the Auto mode and within a very short time, the compressor began cycling. I also tested this theory on the way home from that trip, back to Virginia.

So I suspect that the compressor does not cycle when in the manual mode, however I definitely know it does when Auto is used. I will try this again perhaps one hot day on the way home from work (about a 1 hour drive). At work, I also park in a covered garage. I'd like to see if this is really the case.