🔍 Key Concepts

• Effect of temperature on diesel engine starting • How lube oil viscosity changes with temperature and how it affects cranking speed • Difference between problems that affect cranking speed vs those that affect combustion timing

💭 Think About

• Ask yourself: which option directly affects how easily the engine can be turned by the starter when it is cold, before it fires? • Which options mainly change when the fuel burns in the cylinder rather than how fast the crankshaft is turned by the starter? • In cold conditions, does the lubricating oil tend to get thicker or thinner, and how would that change the resistance to turning the engine?

✅ Before You Answer

• Focus on the phrase "inadequate starting speed during cranking" – this is about mechanical turning speed, not combustion quality after starting • Consider what high vs low viscosity actually means for internal friction in bearings and between moving parts • Separate in your mind fuel injection timing issues (late/early) from mechanical drag issues that resist rotation