Opel Signum
2.8-litre V6 bi-turbo with variable camshaft timing – a concept that makes sense: broad torque band from 1,800 rpm, effortless power delivery across the entire rev range. The sound of a wound-up V6 with turbo flutter on lift-off is unmistakable. Timing chains are the most important maintenance task: elongation possible from 130,000 km, repair 2,000–4,000 €. Idle surging despite new ignition components is a known, hard-to-resolve phenomenon.
V6 turbo touring car
Comfortable long-distance cruiser with 250 hp V6.
Engine Weaknesses 4
Both timing chains stretch and cause camshaft phase offset. Typical from 100,000–150,000 km. Oil channel blockage accelerates the wear.
Symptoms: Rattling on cold start (disappears after 30 sec.), engine warning light, limp mode, valve damage
The Z28NET is prone to misfires and juddering at warm idle. Spark plugs and coils have been replaced without lasting success.
Symptoms: Juddering at idle (warm), brief jolting of the vehicle
Wastegate actuator and turbine shaft on the V6 turbocharger deteriorate. Power loss and fluctuating boost pressure result.
Symptoms: Uneven boost pressure, power loss in the mid-range, occasional limp mode
Fault code for camshaft position bank 2. Often a faulty sensor, but can also indicate timing chain stretch.
Symptoms: Engine warning light, fault codes P0340/P0345, slight rough running
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.
