Opel Signum
Solid naturally aspirated engine from the GM Ecotec series, reaching 250,000 km and more without problems with regular care. Main weaknesses are the electronically controlled thermostat and elevated oil consumption at high mileage.
Signum base
103 kW in the heavy Signum – a little underpowered for the format.
Engine Weaknesses 4
The timing chain is theoretically maintenance-free but can stretch prematurely with neglected oil changes. Hydraulic chain tensioner and guide rails wear depending on maintenance history between 68,000 and 200,000 km.
Symptoms: Metallic rattling or clattering especially on cold start, easing as it warms up. Engine sounds 'like a diesel'. Oil pressure warning light in severe cases.
The map-controlled thermostat from Wahler/Pierburg fails through seal ring failure or electrical fault. If it fails in the closed position, overheating threatens.
Symptoms: Heater barely warm (thermostat stuck open), temperature gauge climbs unusually quickly into the red zone, coolant loss from faulty seal ring.
At mileages above 150,000 km, many Z18XER show increased oil consumption through worn piston rings and oil control rings. Crankcase ventilation and valve stem seals are also possible causes.
Symptoms: Faint bluish smoke from exhaust when accelerating, dropping oil level between changes, oily spark plugs especially on cylinders 1 and 4.
The cam cover gasket becomes porous with age and heat cycling, allowing oil to escape. Oil drips onto hot exhaust components, causing smoke and MOT failures.
Symptoms: Burnt oil smell from engine bay, oil film or drops on cylinder head exterior, faint smoke from hot engine.
Vehicle Weaknesses 12
Electronically controlled ZF-Sachs dampers fail around 90,000–130,000 km. OEM parts over 1,600 €; aftermarket from 150 € per unit.
At the rear roof rail end cap, moisture penetrates between two sheet metal layers causing corrosion.
Cold solder joints in the CIM cause intermittent warning lights without actual fault. Diagnosis requires specialist equipment (Tech2).
On the Signum 1.9 CDTI the EGR valve and swirl flaps clog with soot deposits, causing power loss and smoke. Removal and cleaning costs approx. 100–200 €; replacement is more expensive.
The main radiator of the Signum rusts and leaks from approx. 150,000 km. Radiator replacement requires complete front-end disassembly including AC condenser.
KBA recall for Vectra C and Signum (build years 2002–2007): insufficient spring force in the handbrake lever ratchet.
Track rods and track rod ends show play from approx. 100,000 km. Parts are inexpensive but wheel alignment must be done afterwards.
Rotary knob potentiometers develop contact weaknesses through cold solder joints. Blower occasionally fails completely.
Even without IDS, shock absorbers wear from approx. 100,000–130,000 km. Short-trip use accelerates wear.
The electro-hydraulic steering rack (EHPS) of the Signum leaks oil from approx. 140,000 km. Dashboard warning; sudden loss of steering assistance possible when oil level empty.
On the Signum water enters through leaking tailgate seals or rear light seals into the boot. Spare wheel well fills up.
In the Signum the adhesive between the headliner support rails and fabric deteriorates after 15–20 years due to heat. Foam crumbles; fabric droops.
