Opel Signum
Robustly designed Fiat diesel (GM licence) that achieves reliably high mileage with regular oil changes and motorway use. Critical weak points are the EGR valve, DPF with short-trip use and the dual-mass flywheel.
Signum diesel
88 kW in the Signum – economical, but underpowered for the format.
Engine Weaknesses 4
The dual mass flywheel shows typical wear from around 80,000–150,000 km, especially in city driving. Replacement requires gearbox removal and is usually combined with clutch replacement.
Symptoms: Rattling or clattering at low revs below 1,200 rpm, shaking or juddering when pulling away, noise when engaging a gear that disappears when the clutch is pressed.
The Z19DT uses a timing belt with a replacement interval of 120,000–150,000 km or 10 years. Exceeding this risks belt failure with immediate engine damage from valve contact. Simultaneous water pump replacement is mandatory.
Symptoms: Possibly squealing or faint clattering from timing cover beforehand. When it breaks: engine stops immediately and will not restart.
The EGR valve clogs with soot from exhaust gases, especially with short-trip use. The valve sticks open or closed, triggering the engine warning light and power loss.
Symptoms: Engine warning light after cold start, rough idle, delayed throttle response, power loss at low revs, occasional stalling at standstill.
The diesel particulate filter only regenerates fully on longer motorway runs. Short-trip use prevents self-cleaning; frequent regeneration cycles shorten the oil change interval through fuel dilution.
Symptoms: Glow plug indicator flashes after failed regeneration, increased fuel consumption, strong smell when switching off, 'particulate filter full' warning in instrument cluster.
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.
