After changing the oil or letting it sit for two weeks, I'd crank-up the engine and get a brief second of clatter in the valve train. (hydraulic roller lifters)
To avoid this clatter:
1) Hold accelerator at 100%.
2) Begin cranking the engine. (no more than ten seconds at time - 30 total seconds should be more than enough)
3) After ten seconds or so of cranking, release the accelerator and let it start.
Holding the accelerator at 100% before and during the crank, tells the computer to turn off the injectors so it won't start. I now perform the same procedure with all of my vehicles, including motorcycle. This puts the oil where it needs to be, using very low RPMs, before starting it.
This observation suggests that a cold engine will suffer less damage when initially operated at low-RPM for a period.
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My prior vehicle's engine has an Idle Air Control Solenoid.
http://www.feoa.net/threads/cleaning-the-iac-solenoid.71349/
The valve got stiff over time as it got carboned-up. Sometimes I'd start it up cold and it would idle ~800RPM (where it was on shutdown,) for a bit before gradually idling up to where it should be. The electronically controlled engine was perfectly happy idling at 800RPM even though it was cold. Carburetor distributor engines probably had to idle high just to stay running, but don't believe that is the case with SEFI EDIS engines. The chief reason for high idle with modern systems has to do with the catalytic converter... emissions in other words. The rich fuel mixture and hot exhaust helps get them up to a temperature where they'll begin to catalyze the exhaust. Wikipedia suggests a temp of 800F for efficient operation. However auto manufacturers, as a result of ruined catalytic converters, began flashing the check engine light when a chronic misfire condition is detected. (other emissions problems just turn the light on, but not necessarily flash it) The unburned fuel would overheat and rapidly kill them. Older Oxygen sensors also had to rely on the exhaust to heat them before becoming functional.
Bottom line, high idle wasn't engineered to prevent oil-dilution and for modern vehicles, isn't about preventing a stall. It's about emissions.
Of course, talking about diesel and/or older engine control systems, single digit and negative temperatures, changes the factors a bit. No one is talking about cranking it, immediately putting into gear and gunning it, just as no one is talking about starting it and letting it sit until thermostat-open and/or fan-on. Unrelated anecdote, the oxygen sensor on my prior vehicle had (somewhere between 230-290k on it with,) four wires self-heated, but had to replace it to resolve a spark-knock under load while cold issue. Suspected a failed heater.
