Opel Astra 1.7 DTI G

The Electronic Diesel Unit (EDU) mounted on the injection pump is a well-known weak point on all Y17DT engines. The spill valve solenoid draws high current, which over time degrades the driver circuit through heat. The solder joints crack, causing the engine to not start, start and immediately stall, or cut out intermittently while driving. Common fault codes include P0251 (injection pump fuel metering control) and spill valve errors. Nearly all 1.7 DTI engines develop this problem eventually if the EDU has not been repaired. Specialist repair services rebuild the EDU for approximately €300-400 including labour, with a 12-month warranty. A used replacement ECU costs €80-150, but may develop the same fault again. A new unit from Opel is around €500-600. The repair is the best long-term solution. If the car starts and runs reliably during your test drive, the EDU may already have been repaired or may fail later.

The EGR (Exhaust Gas Recirculation) valve clogs with carbon deposits, especially on cars used predominantly for short trips or urban driving. Symptoms include noticeable loss of power, hesitation on acceleration, increased black smoke, and rough idle. The valve can often be removed and cleaned with carburettor cleaner for minimal cost. If cleaning does not restore function, a replacement valve costs approximately €80-120 for aftermarket and €150-200 for OEM, with about one hour of labour. Some owners choose EGR blanking, though this is not road-legal and may cause issues at emissions testing. Regular motorway driving helps keep the valve cleaner.

The small TD025 turbocharger on the Y17DT can develop actuator sticking or wastegate issues, particularly on cars driven gently at low RPM. Symptoms include the car feeling flat and unresponsive, power loss that temporarily resolves after a restart, and a hesitation below 2,500 rpm. Boost hoses should be checked first for splits or leaks, as these are a cheap fix (€20-50). If the actuator is stuck, a specialist can sometimes free it, but replacement of the turbo actuator or the complete turbocharger may be needed. A reconditioned turbo costs approximately €300-500 including fitting, while a new unit runs €700-1,200 fitted. Driving the car at higher RPM periodically helps prevent carbon buildup in the actuator mechanism.

This is a known weakness on the Isuzu Y17DT engine. The oil pump is driven from the timing belt, and the drive pulley retaining nut can work loose over time. If this happens, the oil pump shaft wears and oil pressure drops, which can cause serious engine damage if not caught early. Symptoms include low oil pressure warning light, ticking or knocking noises, and in severe cases, a worn oil pump shaft. The fix is straightforward if caught during a timing belt change: tighten the nut and inspect the shaft. If the shaft is worn, a new oil pump and pulley cost approximately €150-250 in parts plus €200-400 in labour (typically done alongside timing belt work). The key preventive measure is to always check this nut during every timing belt replacement.

Glow plug failure is common on the Y17DT at higher mileages, causing difficult cold starting, extended cranking, and white smoke on startup. The glow plug warning light may fail to illuminate if the relay has failed. Individual glow plugs cost approximately €10-15 each (four needed), with the relay costing €30-50. Labour is straightforward at about one hour. However, many starting problems initially attributed to glow plugs are actually caused by the EDU solder joint failure described above. If replacing glow plugs does not resolve cold start issues, the EDU should be checked next.

At 20+ years old, rust is the biggest single threat to any Astra G. The rear wheel arches are the most commonly affected area, with paint bubbling progressing to perforation if not treated. The sills, boot floor, and areas under door bump strips are also vulnerable. Many surviving examples have had at least one rust repair. A professional welded repair costs approximately €300-500 per arch, with both sides typically needing attention. If rust has spread to the structural sills or boot floor, repair costs escalate to €1,000-1,500. A cosmetic patch will not last. Applying cavity wax (Waxoyl or similar) to the arches and sills is the most effective preventive measure, but at this age, the question is usually how much rust is already present rather than whether it exists.