Alternator upgrade to fix rough idle issue on 07 Camry LE

[knightnyc]

I have a 2007 Camry LE 4 cyl and experiencing some shaking at idling with the AC on high. The shaking goes away as soon as I turn off the AC. Since the alternator on the 4 cyl camry only has a 100amp max output (probably much lower at idle), I wonder if I should upgrade to a high output alternator with 200+ amp max, 130+ amp at idle. The installation seems pretty straight forward for newbies such as myself and requires few tools. I also plan on upgrading my audio system (3 amplifiers, 2 10 inch subwoofers, total in the 600-800watt RMS range). All suggestions are welcome. thanks.

[Bitter]

upgrade the grounds and alternator wire to the battery and power distribution first. No sense trying to fill a lake through a sippy straw.

[knightnyc]

yes, the power and ground cables will be replaced w/ heavy duty 0 gauge. I am curious whether the higher output alternator will solve the shaking issue when the camry is in idle w/ AC on. Also, I noticed the intake air is quite warm when I circulate air from outside and disable AC. It feels like 20 degrees hotter than the outside temperature. Is it normal?

[lostsignal]

I'm a little confused by your original question. The engine runs rough while it idles so you want to add a bigger alternator? I think that's what you're saying. I'm confused by the "shaking" comment. Or are you using "shaking" and "rough idle" as the same thing?

If you're saying it's the engine that is running rough when the AC is on, then adding a bigger alternator will do nothing for you. A bigger alternator will put more stress on the engine.

[11LE]

^ Yes, more amp output would mean larger alternator.. thought you could find a higher quality one in the same size/weight, but that'd be hard to find. Overdrive pully system for the alternator maybe? But that'd also put more stress on the engine. To lessen the rough idle from the a/c, you could maybe use an underdrive pulley (is one even made for our cars?) but then you wouldn't have enough to power your sound system that you want. I say upgrade all connections and wiring first.

[JSM1284]

An Alternator will not fix. The roughness is caused by the AC compressor. It puts a strain on the engine. I have never seen a car that did not run a slight bit rougher with the AC on. Theres nothing wrong, just more of a load on the engine.

[gdanaher]

If anything, a higher output alternator will exacerbate the problem. The high output alternator requires more energy to convert those additional amps, so it will create more drag on the engine, and this is opposite of what you want. If anything, get an 80 amp alternator and see if smooths it out some.

[Frodo65]

Originally Posted by knightnyc

I have a 2007 Camry LE 4 cyl and experiencing some shaking at idling with the AC on high. The shaking goes away as soon as I turn off the AC. Since the alternator on the 4 cyl camry only has a 100amp max output (probably much lower at idle), I wonder if I should upgrade to a high output alternator with 200+ amp max, 130+ amp at idle. The installation seems pretty straight forward for newbies such as myself and requires few tools. I also plan on upgrading my audio system (3 amplifiers, 2 10 inch subwoofers, total in the 600-800watt RMS range). All suggestions are welcome. thanks.

If the A/C is pulling the idle speed down ( a scan tool will tell you what the ECU is seeing as RPM), then the fix is to allow the IAC to compensate more effectively. I'd check out the following:

1. A common problem is a dirty throttle body, and cleaning it will cure the problem. There are DIY's on cleaning.
2. Another common problem is motor mounts getting less able to manage engine vibrations as they age.
3. Check out the A/C pressures. Excessive pressures will cause higher than normal load, and not allow the ECU to compensate.