recently started noticing that when i put A/c on... engine sound gets thicker and the car feels heavier... almost lilke as it is driving on low or something... as soon as i turn the ac off the engine sound goes and it feels lighter...
anyone else experienced this.... ac works great.. its just the car gets heavier as if its not shiftin through gears and is driving only at 2 or 3rd..
may be its normal.. but don't remember it being there last summer.

 

AC compressor draws power from the engine. Every vehicle I have owned does the same thing. When you turn on the AC the compressor clutch is engaged in the engine which can draw considerable amount of the engines power. Especially in a truck with a large enging as a GX. Some newer vehicles are starting to use electric AC compressor to rememdy this problem. But it's nothing to worry about about 99% with AC has the same symptoms. I remember years ago some magazines use to do acceleration test on vehicles with AC on and off. And with the AC on cars was significant slower than with it off. I hope this alleviate your worries.

 

I have an 06 and also notice a distinct power loss with the AC on. Without AC you can get whiplash accelerating; with AC it actually feels like a truck.

Like nate, I have had this on every SUV or car I have ever owned, so I have come to expect it. Some have been worse than others.

If your rpm keeps shifting to about 2K or so as you increase speed, I assume the gears are actually shifting.

 

Not much loss of power, because these are pretty powerful engines. Now my dad's 1st gen ody, oh boy. To get a good acceleration in the highway, i have to turn the a/c off.

 

Hey GUYS.

Thanks for your replies.. my concern wasn't really the power... when the ac engages... there's always a power loss (which further results in poor(er) fuel economy as well)...
my concern was the SOUND thickness (more like a growl that you get when u put your differential lever to low) and when ur accelerating it feels like the car is in one gear only (in 3rd gear) and is not going higher (to 4th gear) but when u slow down u notice the downshift (to 2nd gear).
Its just the sound which is very heavy... and i din't remember this from last summer... also this is more noticable while driving in the day time... nite time even with AC on engine sound is less noticeable.. hope i explained it properly...

i just hope its normal and doesn't mean less money in my vault. lol

PS - By the way the fans in the front.. (like engine fan ac fan etc) does anyone know where the fuses might be for them...
i remember when i had mL few years back.,.. that behaved in this way when the ac fan fuse blew up and ac fan wasn't working... also the hood use to get hot.... i wanna check if thats the problem.. though i hope not..

 

IN the terrible heat, I can't not have the Air Conditioning on and I also notice exactly what you describe. The sound of the engine becomes more "whooshy" and less like normal is the best way I can describe it. I assumed this was from the A/C because with A/C off, the added noise does go away.

For the shifting with the A/C on, I have a feeling that maybe the transmission prefers lower gears to keep the RPMs higher and closer to the "power belt" so that when you ask for acceleration, the car has a better chance of giving you the acceleration you need. That is just what I guessed. I don't really know. But, everything is normal.

 

Ok thanks for replying.. well i feel alot better knowing that its not just my lex. well i don't notice this sound thing in any other suv i have driven .. even my landcruiser which is also a V8 and it doesn't do this... i mean i do notice slighty higher engine noise but not the engine growl like gx...

 

Was just about to post about this, good to know its not only my vehicle.