Most 2017 Jettas on the Irish market use VW's 1.6 or 2.0 TDI engines; they are economical on long runs but can show DPF/EGR soot buildup if mostly used for short trips. The manual versions commonly have a dual-mass flywheel and clutch that can be expensive to replace if worn, and the timing belt/auxiliary belt replacement history is worth checking on a 9-year-old car.

• DPF/EGR condition — ask for evidence of regular long-run use or recent forced regens; check for warning lights and heavy smoke on start.
• Clutch and dual-mass flywheel — test for slipping, judder or rattles when cold and during clutch engagement.
• Timing belt service record — confirm replacement interval was respected (older TDIs usually need belt changes around major service milestones).
• Turbo and oil leaks — check for excess smoke, oil around turbo/intercooler hoses and clean intake piping.
• Gearbox syncros and linkage — ensure smooth shifts through all gears, especially 1st and 2nd, and listen for crunching or excessive gear play.