Oliver Enterprises

There is a similar thread HERE regarding low idle. But I want to go a different route with this thread. Because I can control if my car low idles or not. And I suspect many others can as well.

This subject Low Idle, is on a fully warmed engine with the car in ‘D’rive.

Of late, with really nice weather, I tend to turn off the air, and even the fan, and I lower both left side windows. Lowering the left rear window smooths the airflow at the driver’s window making the ride much more pleasant versus the driver’s window down alone. I’ve been putting the windows down in order to hear the Exhaust Vents. But that’s another topic.

Under these conditions, when I come to a stop, at a traffic light, or when slowly coming into my garage, the rpm will be down to like 500 rpm. And there is some vibration to be felt. I bring this up because, I feel there is no problem with the engine or any component really. And I have zero acceleration issues. But I notice the following, and wanted to see if you fine folk would simulate this and see if your vehicle does the same thing. What sets the low idle in motion are the following conditions:

• A/C: OFF (both front and rear)
• Seat heating / cooling: OFF (all seats)
• Parking / (almost) Nike lights: OFF

At a stop, no throttle, warm engine, in gear, it will low idle.

Things that return the engine to its normal rpm:

• When I change the either front seat setting from OFF, to seat cooling (any speed), or seat warming (any speed), or
• If I turn on the (almost) Nike lights.

The engine then idles at the correct speed, somewhere in the 650 rpm range. The vibration is due to a harmonic imbalance of the engine at 500 rpm. At ~650 rpm, it is smooth as butter, hence why it is supposed to idle at this speed.

Does anyone else’s LS exhibit the ability to low idle?

213374U

Mine does the exact same except will still idle low with the Nike lights lit. Doesn't concern me, but it is startling when an otherwise unbelievably smooth running vehicle starts producing feedback.

Oliver Enterprises

213374U, what year is yours?

sktn77a

iTrader: (2)

Mine, too.

213374U

She's a 2010

johnnyg66

Yep. I usually leave the Air on even if the windows are down. The only other odd thing i use to see was a idle that would drop just under 500 than go to maybe 600. It would happen every 10 secs or so at a stop. Did this for months and now it won't do it.

k311in

iTrader: (4)

The nike light can be turn off or on? Might be a silly question

ALK

Same my 07 has low idle when no lights is on , i always keep the parking lights on when i use the car . I turned off DRL so only nike lights.

Oliver Enterprises

Would you guys mind including your year model? Mine is a 2010.

ALK - You bring up an interesting point. I have no love for DRL's. And on our cars, running the DRL's make the Nike lights less visible. At some point (maybe 2010), turning off the DRL's became part of the customizing programming within the Nav unit. So, one of the first things I did was turn them off.

I wonder, if my vehicle (and others) are set up to default run the DRL's. So ... assuming if I turned everything else off in the vehicle like I mentioned in my first post, which sets the car to idle low ... if I turned the DRL setting back on, I wonder if it would then idle correctly at like 650 rpm. I didn't drive my car today or I would go outside and check that out. But I'm guessing there's a pretty good chance that with the DRL on, it would idle correctly.

And thus, is why I wanted to start the thread. To come across such info, to jog loose a possible root cause. I bet that when Lexus decided to include that into the custom menu, they neglected to account for the lack of all these electrical loads, so they didn't program for it. Man, I wish I had my car here so I could see if that solves the issue.


Jason

213374U

I bet you're right, I've disabled my DRL's as well.

johnnyg66

In my 07 it made No difference.

Oliver Enterprises

Johnny - You may be right. But you have to have all the right conditions to test it. Fully warmed, in gear, no Nike lights, no A/C, no seat heat, no seat cooling, maybe even no hvac (I say that because frequently when I put my windows down, I turn off the hvac. I may not touch the car all weekend. There's a big bmx event this weekend. The truck takes care of that duty.

djkneekap

Same thing on my '07. It typically stays around 750-800 at a stop with everything off and warm engine - still have slight vibration, enough to bother me but I'm very ****. I have noticed it hovering around 500 though at times. I get vibration at both. Once in i pop it in neutral though, can't even tell it's running...

Doublebase

Oliver Enterprises

I drove the sled in this morning, due to the good weather today. On the way in, I pulled into a handicap spot for 30 seconds because it faces windows of the office building. I can see the reflection of the car in the windows.

I had the windows down, hvac off, Nike lights off, seat heat / cooling off, stopped in the spot in D, and the car was low idling just under 500 rpm.

I had already activated the magic button that allowed me to go into the customization menu while driving, and had the button ready to push to reactivate the DRL's. So, with it in D, I turned them back to on, and pressed SAVE. Once the menu screen timed out, the DRL's came on. However, no change to the rpm. Still just under 500 rpm. So my theory that the lack of the DRL electrical load could be the factor was blown. That's not the issue.

So, back to OFF the DRL's went. They would have been turned back off either way. Back to the drawing board!


Jason