Opel Signum
Naturally aspirated V6 with 211 hp. Known for oil cooler leaks and head gasket problems. Solid engine when oil/cooling system are in order.
V6 luxury liner
Rare top model with 3.2 V6 and automatic. Long-distance car with style.
Engine Weaknesses 4
The oil-water cooler located between the cylinder banks becomes porous and mixes oil with coolant. Repair is complex due to the V6 geometry.
Symptoms: Oil in coolant (brown emulsion), coolant consumption with no visible leak, steam from engine bay
The head gasket gives way at high mileage. Both sides of the V6 must be treated, making the repair very labour-intensive.
Symptoms: Heavy oil loss at exhaust manifold, coolant loss, white exhaust gases
Cam cover gaskets and oil pressure switch leak regularly. Escaping oil can migrate along the wiring loom into the ECU.
Symptoms: Visible oil seeping from cam cover, oil spots under vehicle, in the worst case ECU failure
Above 220 km/h a strong vacuum develops that draws oil past the valve stems. Not noticeable in normal use.
Symptoms: Increased oil consumption with frequent motorway driving, blue smoke on overrun at high speed
Vehicle Weaknesses 13
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 with automatic gearbox (especially 2.2 DTI, 2.8 V6) harsh shifting and delayed gear engagement occur at operating temperature. Gearbox oil change can help but is not a cure-all.
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.
