Cerbera known weaknesses and common faults
A consolidated checklist of the faults TVR Cerbera owners most often report, with the parts and donor cross-references that tend to come up alongside each one. Use it as a starting point when buying, inspecting or troubleshooting a car — it is not a substitute for a proper hands-on inspection.
Applies to: TVR Cerbera (AJP8 4.2 and 4.5, Speed Six 4.0). Some items also affect the Griffith and Chimaera and are flagged where relevant.
AJP8 V8 (4.2 and 4.5)
Section titled “AJP8 V8 (4.2 and 4.5)”The AJP8 is generally robust mechanically but has a few well-known weak points around ignition and the dry-sump oil system.
| Area | Symptoms | Notes / replacement parts |
|---|---|---|
| Coil packs | Misfire, rough running, cylinder drop-out | Very common. Citroën ZX 1.6i coils are the usual substitute — GSF 925PC0090, two required. Worth carrying a spare. |
| Dry-sump system | Oil leaks at hoses and unions; cracked oil tank | Inspect hoses for perishing; check tank for cracks. Don’t overfill — too much oil causes its own problems. |
| Water pump | Overheating, coolant loss, noise from pump area | Replace the thermostat at the same time as a matter of course. |
| Thermostat housing | Coolant weep around housing | Thermostat QTH221 (85 °C, original) or QTH134 (78 °C, cooler alternative). |
| Camshaft wear | Less common than Speed Six but reported on high-mileage engines | Frequent oil changes are the best defence. |
Speed Six 4.0
Section titled “Speed Six 4.0”The Speed Six has a reputation for top-end wear. Early engines are the worst, and a service history with short oil-change intervals is essential.
| Area | Symptoms | Notes |
|---|---|---|
| Camshafts and followers | Power loss, rough running, poor idle, metal swarf in oil | The headline Speed Six fault. Revised cams and followers are available; oil changes every 3,000 miles are widely considered mandatory. |
| Oil pump drive | Oil pressure drop, warning light flicker | Can be catastrophic. If the oil light flickers, stop the engine immediately. |
| Head gasket | Oil in coolant, coolant loss, overheating, white smoke | Often a full rebuild by the time it shows. |
| Valve seat recession | Gradual loss of compression, poor running | Worth a compression test on any prospective purchase. |
Brakes
Section titled “Brakes”Brake servo corrosion affects all of the Griffith, Chimaera and Cerbera family — see the dedicated brake servo pages on this wiki for replacement options.
| Component | 4.5 Cerbera | 4.2 Cerbera |
|---|---|---|
| Front calipers (AP Racing) | CP5200-802 / 803 | CP5100 family (with 291 mm discs) |
| Rear calipers (AP Racing) | CP5211-22SO / 23SO | 2-piston |
| Seal kits | AP Racing dealers or Shop4Brakes | AP Racing dealers or Shop4Brakes |
Check for sticking pistons and uneven pad wear at every service, and inspect the underside of the servo for corrosion.
Caution: Brakes are safety-critical. Any servo, caliper or hydraulic work should be carried out to the manufacturer’s spec and torque figures, or by a competent specialist.
Body and chassis
Section titled “Body and chassis”- Water ingress — door seals harden with age; check footwells and boot for damp, and look at the dashboard bungs. Improved aftermarket seals are a common fix.
- Chassis corrosion — the tubular backbone chassis can rust, particularly at rear outriggers, floor pans, wishbone mountings and jacking points. Light surface rust is normal; structural rot is a job for a TVR specialist.
- Door mechanisms — the push-button doors (1996 on) can fail. Common replacements are Spal actuators for the door openers, and Maplin YD79L or YD78K motors for the central locking.
Electrical
Section titled “Electrical”| Item | Common issue | Notes |
|---|---|---|
| Speedometer | Failure of the magnetic sender | Check before purchase; senders are replaceable. |
| Temperature and oil pressure gauges | Inaccurate readings | Cross-check with an IR thermometer / mechanical gauge before condemning a sender or pump. |
| Fuel pump relay | Pump won’t run | Check the relay before the pump itself — it’s the more common culprit. |
| Ignition relay | Intermittent no-start | Carry spares of all relay types fitted. |
Fuel system
Section titled “Fuel system”- In-tank fuel pump can fail; always check the relay and feed first.
- Fuel hoses perish with age and cause fuel smell in the cabin or boot. Replace with modern EFI-rated hose to the correct pressure spec.
Exhaust
Section titled “Exhaust”| Item | Part |
|---|---|
| Rear box mounting rubbers | Bosal 255-593 or Powerflex EXH 005 |
| Manifold / joint cracks | Common — usually repaired by welding |
Interior and air conditioning
Section titled “Interior and air conditioning”Dashboard instruments can fail individually — confirm every gauge and warning lamp works. The two-spar steering wheel is Cerbera-specific. Leather wear on the outer seat bolsters is normal, and the rear seats are best regarded as occasional (the 3+1 layout is very tight).
For the air-conditioning system, owner-friendly cross-references are:
| Component | Cross-reference |
|---|---|
| Condenser (radiator) | Hella — approx. £135 + VAT |
| Drive belt | Gates Micro-V 58374 / 5PK 1113 |
| Tensioner pulley | Vauxhall 2.0 16v cambelt pulley VKM25211 |
Pre-purchase quick checks
Section titled “Pre-purchase quick checks”- Listen for a steady idle and watch for the oil light flickering on a hot Speed Six.
- On an AJP8, look for damp around the thermostat housing, water pump and dry-sump hoses.
- Press every door button and try the central locking from both sides.
- Lift carpets in the footwells and check the boot floor for water staining.
- Inspect the servo and chassis outriggers from underneath with a torch.
- Confirm all gauges, warning lights and the speedometer work on a short test drive.
Compiled from TVR owner forums and community knowledge — always verify against the original sources and a specialist inspection before relying on it.