🔍 Key Concepts

• Lube oil sludge forms from contamination, oxidation, and breakdown of lubricating oil • How sludge moves with the oil through the suction strainers, bearings, and piston areas • The difference between a single specific consequence and multiple related consequences in engine systems

💭 Think About

• Think about where lube oil actually flows in an engine: what components does it pass through first, and which of those are most sensitive to sludge buildup? • Consider how sludge might affect oil flow and heat removal—what happens to temperature and moving parts if oil can’t flow freely? • Ask yourself whether sludge is likely to cause only one of the listed problems, or if several of these issues could reasonably appear together in a neglected system.

✅ Before You Answer

• For each option, imagine sludge physically present there: Can it realistically block, insulate, or stick that component? • Check your engine knowledge: does reduced oil flow or contaminated oil tend to cause only pump problems, only temperature problems, or also wear and sticking of moving parts? • Before choosing, verify whether any listed effect would be unlikely or unrelated to sludge, and rule those out first.