ICE-49 — Used ICE Vehicle Assessment

ASSUMPTION — This lesson covers assessment method; it is not amateur-intervention instruction. Real tests should be done by a competent service.

In this lesson you will learn:

• How to assess engine health
• Compression, oil, turbo and injector checks
• The role of OBD and service history

1. Why Engine-Focused?

A used ICE vehicle’s value and reliability depend heavily on the engine and emissions systems’ health; faults there are costly.

FACT — Engine health is assessed via compression, oil consumption, coolant condition, turbo, injectors, DPF/EGR/SCR and misfire.

2. Compression and Oil Consumption

• Compression test — pressure differences between cylinders reveal ring/valve wear.
• Oil consumption — excessive use can indicate ring/valve-guide wear.

FACT — A marked compression difference or low compression may indicate worn rings/valves or a head-gasket issue. Blue exhaust smoke indicates oil burning.

3. Turbo, Injectors and Aftertreatment

• Turbo — whistle/oil leaks, excess play affect health.
• Injectors — rough idle, smoke, fuel smell suggest injector issues.
• DPF/EGR/SCR — a clogged DPF or faulty EGR/SCR is expensive.

FACT — In diesels, short-trip use can cause DPF fill/regeneration problems; the SCR/AdBlue system must also be checked (ICE-23, ICE-24).

4. Cold Start, Smoke and Misfire

FACT — Cold-start difficulty, excessive smoke or misfire may indicate injection, ignition or compression problems; these are assessed on a test drive and via OBD.

5. OBD and Service History

FACT — An OBD read (DTC, readiness) can reveal hidden faults; regular service history and timing-system maintenance are also critical to engine life.

6. Summary

• Check compression, oil, coolant, turbo, injectors and aftertreatment.
• Cold-start, smoke and misfire symptoms matter.
• OBD + service history complete the assessment.

7. Sources

• Bosch Automotive Handbook
• SAE J1930

Next Lesson

• ICE-50 — Troubleshooting Case Studies.