Editing Diesel engine (section)

===Cold weather starting===
In warmer climates, diesel engines do not require any starting aid (aside from the [[Starter (engine)|starter motor]]). However, many diesel engines include some form of preheating for the combustion chamber, to assist starting in cold conditions. Engines with a displacement of less than 1&nbsp;litre per cylinder usually have [[Glow plug (diesel engine)|glowplugs]], whilst larger heavy-duty engines have [[flame-start system]]s.<ref name="Reif_2014_136" /> The minimum starting temperature that allows starting without pre-heating is 40&nbsp;°C (104&nbsp;°F) for precombustion chamber engines, 20&nbsp;°C (68&nbsp;°F) for swirl chamber engines, and 0&nbsp;°C (32&nbsp;°F) for direct injected engines.

In the past, a wider variety of cold-start methods were used. Some engines, such as [[Detroit Diesel]] engines used{{When|date=September 2010}} a system to introduce small amounts of [[Diethyl ether|ether]] into the inlet manifold to start combustion.<ref name="FreeLib_1995" /> Instead of glowplugs, some diesel engines are equipped with starting aid systems that change valve timing. The simplest way this can be done is with a decompression lever. Activating the decompression lever locks the outlet valves in a slight down position, resulting in the engine not having any compression and thus allowing for turning the [[crankshaft]] over with significantly less resistance. When the [[crankshaft]] reaches a higher speed, flipping the decompression lever back into its normal position will abruptly re-activate the outlet valves, resulting in compression − the flywheel's [[mass moment of inertia]] then starts the engine.<ref name="Hawks_73" /> Other diesel engines, such as the precombustion chamber engine XII Jv 170/240 made by Ganz & Co., have a valve timing changing system that is operated by adjusting the inlet valve camshaft, moving it into a slight "late" position. This will make the inlet valves open with a delay, forcing the inlet air to heat up when entering the combustion chamber.<ref name="Kremser_1942_190" />