Turbo underboost on Land Rover 2.7/3.0 TDV6 — twin-turbo system imbalance or split intercooler hose.
Land Rover P0299 — Turbo underboost on Land Rover 2.7/3.0 TDV6 — twin-turbo system imbalance or split intercooler hose. Typical UK independent garage cost: £220–£2800.
What actually causes P0299 on a Land Rover
TDV6 twin-turbo systems suffer from cracked intercooler hoses, sticky low-pressure turbo VGT actuator and the well-known cracked exhaust manifold. P0299 alone rarely means a dead turbo on these — diagnose the upstream causes first.
Land Rover engines that log P0299
- 2.7 TDV6 (Discovery 3, Range Rover Sport)
- 3.0 TDV6 SDV6 (Discovery 4, Range Rover Sport)
How we diagnose P0299 on a Land Rover
- Smoke-test the full charge-air system
- Inspect both turbo actuators — sweep test
- Check exhaust manifold for cracks (ticking cold)
- Read live MAP and MAF data during boost demand
The common misdiagnosis to avoid
Garages quote both turbos as a precaution — on TDV6, identify the failed unit (low or high pressure) before quoting £2k+ in parts.
Land Rover P0299 repair cost in the UK
Expect £220–£2800 including parts and labour at an independent garage. Main-dealer quotes on Land Rover are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.
Bob's workshop tip
TDV6 P0299 — manifold cracks and split hoses cause more P0299s than dead turbos. Always smoke-test first.
Codes usually seen alongside P0299 on Land Rover
- P0234
- P2563
- P132B
Symptoms drivers report with P0299
- Loss of power above 2,000–2,500 RPM — car feels flat overtaking on the motorway
- Limp mode kicks in at 3,000 RPM, resets after a key cycle, then returns within 10 miles
- Whistling from engine bay under load — split intercooler pipe or Y-piece
- Black smoke or fuel smell from the exhaust on diesels — VNT stuck open, over-fuelling
- Paired codes: P0234 (overboost, VNT stuck closed), P0299 with P0401 (EGR + boost overlap), P0299 with P132B (turbo boost control)
Repairs that clear P0299
- Smoke-test the boost system first (cheap and finds most causes)
- Clean VNT vanes with rocker-arm actuation
- Replace boost sensor
- Replace turbo as last resort
For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0299 guide.