IsItAGoodCar
Reliability Guide

Common Problems with the
1999 Bentley Continental R

We've identified 3 known issues that can affect the 1999 Bentley Continental R. 3 of these are serious faults that could be expensive to repair.

3
Known Issues
3
Serious
0
Moderate
0
Minor

All Known Issues

Sills, Wheelarches and Subframe Corrosion

SeriousBodywork & Rust

Despite hand-crafted assembly at Crewe, the heavy steel unitary bodyshell of the Continental R is highly vulnerable to moisture and road salt entrapment along the lower outer and inner sills, rear wheelarch lips, and front bulkhead seams. Water often collects behind plastic wheelarch liners and windscreen scuttle drains, rotting hidden structural mounting points that can result in MOT structural failure and tens of thousands of pounds in specialist coachbuilding repairs.

Est. Repair Cost: £2,500–£8,000
Warning Signs:

Bubbling paint along lower sill flanges and wheelarch lips, Damp or musty smell inside front footwells after wet weather, Cracking or flaking underbody sealant near rear suspension mountings, MOT failure for structural rust within 30cm of safety-critical mounts

What to Inspect:
  • Probe along entire length of inner and outer sills with a non-marking plastic tool
  • Lift boot carpet and inspect spare wheel well and rear bulkhead seams for water ingress or brown staining
  • Inspect front scuttle drain tubes beneath windscreen wipers to ensure free drainage
  • Examine MOT history records on GOV.UK for corrosion advisories or welding repairs
Verified by IsItAGoodCar Research TeamUpdated

Zytek Engine Management Sensor and Harness Degradation

SeriousElectrics & Electronics

Post-1995 Continental R models (featuring the 385–420 bhp turbocharged V8) rely on a proprietary Zytek electronic engine management system. As underbonnet heat accumulates in this tight engine bay, the engine bay wiring harness insulation becomes brittle, and critical proprietary sensors—including crank position sensors, air mass sensors, and charge temperature senders—suffer heat soak failure. Sourcing and recalibrating proprietary Zytek ECUs and sensors now requires specialist electronic reconditioning.

Est. Repair Cost: £1,200–£3,500
Warning Signs:

Intermittent engine cutting out or stalling when warm, Engine cranking but failing to start when hot (crank sensor failure), Uneven or hunting idle speed with black exhaust smoke, Loss of boost and engine dropping into limp home mode

What to Inspect:
  • Inspect underbonnet wiring loom conduit near turbochargers for heat baking and crumbling insulation
  • Check engine starts cleanly from both dead cold and hot operating temperatures
  • Verify that the car maintains smooth idle at 600rpm in gear with air conditioning running
  • Review specialist invoices for Zytek ECU repairs, wiring harness rewires, or sensor replacements
Verified by IsItAGoodCar Research TeamUpdated

Hydraulic Braking System and Rear Gas Sphere Failure

SeriousBrakes

The Continental R relies on the complex Bentley twin-circuit hydraulic system operating at over 2,000 psi to power the brakes and self-levelling rear suspension. Rubber diaphragms inside the hydraulic accumulator spheres perish with age, causing the system to lose hydraulic buffering capacity. This results in heavy brake pedal resistance, hydraulic pump chatter, and rock-hard rear damping that transmits road shock directly into the coachbuilt chassis.

Est. Repair Cost: £900–£2,800
Warning Signs:

Hard wooden brake pedal feel upon initial pedal travel, Brake low pressure warning light illuminates on dashboard during braking, Rear of vehicle sits down or takes extended time to raise after starting, Extremely stiff and jarring rear suspension compliance over bumps

What to Inspect:
  • Test brake reserve by pumping pedal 20-30 times with engine off to measure accumulator discharge
  • Check hydraulic fluid sight glass or reservoir for correct green mineral fluid condition
  • Inspect metal brake lines running above rear axle subframe for rust and pitting
  • Check for hydraulic fluid leakage around rear height-control valve and strut boots
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 1999 Bentley Continental R

  • Inspect the length of the sills, wheel arches, and windscreen scuttle drains for rust; coachwork restoration on these hand-built shells is very costly.
  • Test that the twin hydraulic braking circuits build and retain pressure, and verify that the brake warning light extinguishes promptly on startup.
  • Ensure the car starts crisply when fully up to operating temperature; hot-start hesitation often signals a failing Zytek crankshaft sensor.
  • Verify that all bespoke interior electrical adjustments work smoothly, including the electric seat memory, tilt steering column, and climate control.
  • Examine the service history for regular replacement of brake accumulator spheres and hydraulic mineral oil flushes.
Check a 1999 Bentley Continental R by Registration