3GSShoe

It’s still there I bet. Just the new engine mounts is solid enough to keep it from feel like it’s misfiring.

Vtallysx4

Oh it idles low in the ideal scenario, but there is no stumbling and it never felt like a misfire. The new motor mounts just do their job and I can't feel it.

johnw460

I had the same problem on my 2007 LS 460. I bought it last year. Low miles and mint condition. After I got it I changed all of the fluids and spark plugs. Replacing the spark plugs requires removing the battery. After doing this work I noticed the low idle with the fan and AC off. Idled according to the gauge about 450 rpm. It even stalled a few times at red lights. So I went back and replaced the spark plugs again, cleaned the throttle body, cleaned the MAFs, poured fuel cleaner in the tank a few times and did Italian tune ups, and none of that helped. The idle was always low when in drive only. I went back and looked over everything I did. Did I leave a vacuum hose disconnected, nope. No check engine light.

I took it to a Lexus dealer and paid them $170 to diagnose it and they couldn’t find anything wrong. I started to think maybe I’d just need to live with this and always leave the AC or fan on. Even with the AC or fan on the idle would fluctuate a bit at red lights.

I stumbled on something about idle air control valves. If any car doesn’t idle properly this could be the culprit. Apparently with Lexus and Toyota if the battery is disconnected (which I had to do to replace the plugs) the car might idle low after about being reconnected. With Lexus and Toyota there is an idle air control valve relearn procedure. There are videos all over YouTube on how to do it. But essentially what you do is turn the ignition to the “on” position, turn it back off, then turn it to the “on” position a second time, then turn the ignition back off. Do all of this after you’ve driven the car around or let the engine warm to operating temperature. Apply the parking brake, turn the car on and put it in drive. Leave it idling in drive for 5-10 minutes. And it worked! No more low idle problems. Idles smooth and steady now. I’m very happy, so I wanted to share this here. So if you’ve replaced your battery or had it disconnected or it died on you, maybe give this a try.

3GSShoe

That’s weird that the idle air control valve needs relearning. It’s either on or off in many Toyotas. Off being that it’s fouled up with carbon and the motor is stuck which is a simple fix with a blast of electronic cleaner.

My low idle happens maybe 1 out of 15-20 drives. I’ll give the procedure a try.

swfla

iTrader: (1)

This has been an unanswered and ongoing mystery. A second owner doing this successfully may be the answer...

Gerf

Can you take a picture of this valve and post it ?

Striker223

Deleted for the meme factor

3GSShoe

Is this done with the A/C on or off? Mine usually gets low idle w/the A/C off so I presume maybe doing the procedure with the air off

i see some people online put their car in neutral and then shut off the engine