Remote Start and Idling: What It Does and Does Not Do

Long idling in an Iowa January is one of the most common winter habits and one of the most misunderstood. Comfort is a perfectly good reason for it; engine protection mostly is not. Questions welcome at Des Moines Auto Repair on (515) 305-3210.

The advice comes from carburetors

Extended warm-up made real sense when engines used carburetors, which metered fuel mechanically and ran badly until warm. Driving off cold risked stalling and poor running.

Fuel injection with engine management removed that problem entirely. A modern engine adjusts fueling and timing continuously and will run correctly from the moment it starts, so the practice outlived the reason for it.

What a cold engine actually needs

Thirty seconds to a minute allows oil pressure to come up and oil to reach the top of the engine, which is the part that matters for wear. Beyond that, idling warms the engine very slowly because it is producing almost no load.

Driving gently warms everything faster, and it warms the parts idling never reaches. A transmission, differentials, and wheel bearings only warm up when they are turning, so a car idled for fifteen minutes still has a completely cold drivetrain.

The cost of long idling

A cold engine runs a rich mixture, and unburnt fuel washes past the rings into the oil. Extended idling at low temperature dilutes engine oil with fuel over a winter, which reduces its ability to protect.

Carbon builds up on valves and in the exhaust for the same reason, and a vehicle used exclusively for short idled trips accumulates it noticeably faster.

Fuel consumption while stationary is straightforward waste, and in this state it is also a theft risk with keys in an unattended running car.

Where remote start earns its place

Cabin comfort and clearing glass are genuine benefits and worth having. A warm cabin also means a driver who is not distracted by scraping a windshield through a two-inch porthole.

Heated seats and a heated steering wheel reach comfort far faster than the engine heats the cabin, and they draw a fraction of the fuel.

The efficient pattern is a short remote start to take the edge off and clear the glass, then drive gently for the first several minutes.

The garage rule

Never remote start a vehicle in an attached garage, including with the door open. Carbon monoxide accumulates faster than most people expect and it migrates into the house.

Modern systems have safeguards and none of them substitute for the door being open and the vehicle being outside.

Block heaters do the job idling cannot

A block heater warms the coolant and therefore the engine itself before it ever starts, which reduces the cranking load on the battery and shortens the period of high wear after ignition.

Two to four hours on a timer before you leave is sufficient; running one overnight is wasted electricity. In Iowa they remain genuinely useful and are underused on vehicles that have them fitted.

Diesel is a different case

Diesel engines take considerably longer to reach operating temperature and their manufacturers often do specify idle warm-up in severe cold. Anyone running a diesel pickup here should follow the manual rather than the gasoline guidance.

Glow plug systems and fuel gelling in extreme cold are separate winter considerations worth a conversation before December.

Snow and the exhaust pipe

The genuine danger of remote start in an Iowa winter is a tailpipe packed with snow. A drift against the back of a parked car, or snow thrown up by a plow overnight, blocks the exhaust and sends carbon monoxide back toward the cabin.

Walk behind the vehicle and check before starting it remotely after any snowfall. It is a ten-second habit and it is the one that matters most.

The same applies to a vehicle stuck in a ditch with the engine running for heat, which is a scenario this region produces every winter.

Battery drain from short winter trips

Remote start compounds a problem that Iowa winters create anyway. Each start is a large withdrawal from the battery, and a remote start followed by a five-minute drive takes out more than the alternator puts back.

Somebody who remote starts twice a day and drives short distances is running a chronic deficit through the whole season, which is why batteries fail in February rather than gradually.

A longer drive weekly, or a maintenance charger on a car that mostly sits, resolves it.

Serving Des Moines and the surrounding metro. Call (515) 305-3210.