I own a 2013 ES 350 with 5000 miles.

On cold weather conditions, doing a cold start, I allow the engine to run and warm up for a minimum of 5 minutes before driving. In this time frame the engine goes thru the whinning sound and then the engine noise is quiet (normal).

What do other owners allow for engine warm up time before driving.

 

Most manufacturers would say that a car requires only a minute or two to "warm up". After that you're wasting gas. Now, welcome to my world (in Pennsylvania) where last night it was 9 degrees. My wife starts the car at least 15 minutes before leaving so the seats are warm and the heater has started. She's cold in August. So really, its a matter of what works for you. I don't think that either scenario is injurious to the car.

 

In carburetor days, the logic was that the car would run rich with the choke open, without any throttle action to reset the fast idle. So rich that you could dilute your oil with the gas blow-by. The emission controls are so smart now, aside from wasting the gas, probably no harm. I think that's why remote start is so common now.

 

I also noticed the whining sound during cold start ups and the tachometer going up to 1500rpm then gradually coming down in about two to three minutes to idle RPM. My previous car was and Audi and at cold start it would idle like it had been running for two hours.

Would like to know what is causing the whining sound at initial cold start. Also a mechanic friend thought it was Lexus's way to get the catalytic converter to get hotter for better emission control.

Like to hear what others think

 

it's really the same concept as jim256 layed out. Ambient temperature does make a differance in the mixture of fuel, air, and rpm to succsesfully start the engine and keep the balance just right. With the carburetor, when first started in cold weather, it would set itself at what was called "high idle" (very technical words) lol. Any how as the engine warmed the links/controls on the Carb. kick out of high idle and the engine drops to normal idle rpms.

With our Lexus, it's basically the same thing only a whole lot better. First of all it works! Keeping a Carb. in perfect adjusment or from flooding just as your trying to make a right turn in traffic.was just a pain in the butt. I can't explain all of software and processors that Lexus use's to perform this function. But as you noted, when its cold your car will idle at a higher rpm at first, usually around 1,800. But as it warms it usually comes down to 600-800 rpm. I too have a remote start and with the cars computer controled ignition, I can press my button and know the car will start every time!!! That was never true with the carburetor, let it run, and if I get distracted the remote start will automatically shut off after 18 minutes.

Yes, that does waste gas. But as I'm writing this, it is -5 F outside. You bet I'm going to let it run!!

Have a good week.

Paul