Range Rover L405 Engines: TDV6 vs SDV6 vs SDV8 vs V8

November 6, 2026

Compare Range Rover L405 TDV6, SDV6, SDV8 and V8 Engines, Common Faults and UK Replacement Costs

Choosing a Range Rover L405 engine? This guide compares TDV6, SDV6, SDV8 and 5.0L V8 on ownership costs, reliability and replacement options.

• Most reliable: 3.0L TDV6 (306DT, single turbo) — 255–258 bhp
• Performance diesel: 3.0L SDV6 (306DT, twin turbo) — 296–306 bhp
• Heavy towing: 4.4L SDV8 (448DT) — 339 bhp, up to 3,500 kg
• Performance petrol: 5.0L V8 Supercharged (AJ133) — 503–557 bhp
• Fitted replacement: £5,400–£7,200 (V6 diesels) · £7,000–£9,000+ (SDV8) · £8,000–£12,000+ (V8)

Before committing to a usedRange Rover L405 engine replacement, compare prices for the same variant and fitting scope. A headline engine price alone does not tell you what the complete job includes.

Explore Range Rover L405 engine problems, compare TDV6 vs SDV6 vs SDV8 vs V8, and review indicative UK replacement costs. Use the buying checklist below to assess service history, warranty terms and supplier quotes.

TDV6 vs SDV6 vs SDV8 vs V8: L405 Engine Comparison

The pattern is simple: the more turbos added, the more complexity, and the more that maintenance history matters.

Is the 3.0L TDV6 the Best-Value L405 Engine?

The 3.0-litre TDV6 (306DT) uses a single turbocharger, which means less thermal and mechanical stress than its twin-turbo SDV6 sibling. It produces 255–258 bhp and 443 lb-ft — ample for daily driving and moderate towing.

That simplicity is why it's the most sought-after L405 engine for long-term ownership. It's also the cheapest to replace: £5,400–£7,200 fully fitted. For most buyers, this is the best-value combination of reliability, running costs and replacement cost.

How Much Does a Range Rover L405 Engine Replacement Cost in the UK?

When comparing reconditioned Range Rover L405 engine replacement costs in the UK, treat the figures above as indicative rather than a fixed quote. Ask for an itemised breakdown of the engine, labour, gaskets, fluids and diagnostics, and confirm which additional components are included.

What Might an L405 Engine Replacement Quote Exclude?

While an L405 engine is removed, these are the items usually worth renewing — and not always inside the headline price:

• DPF
• EGR valve
• Turbocharger
• Water pump
• Coolant hoses and pipework
• Fluids and filters

For an L405 engine supply and fit quote, confirm whether VAT, delivery and fitting are included, and whether these ancillaries are in scope. Compare the written breakdowns rather than the headline prices alone.

What Are the Common Faults with Each L405 Engine?

Understanding Range Rover L405 engine faults helps you frame questions about a replacement. Ask which problems have been diagnosed and what work is included in the proposed repair or replacement.

TDV6 — oil cooler seals weep, EGR valves clog, DPFs occasionally block. All are manageable, and all respond to servicing every 10,000 miles. This is the variant where a well-maintained used unit can genuinely be a bargain.

SDV6 — timing chain stretch on pre-2014 cars, turbo actuator failures and swirl flap issues. Twin-turbo complexity means oil discipline is everything. A stretched chain on an SDV6 is an engine-out job, which is why history matters more here than on any other L405.

SDV8 — injector failures and complex turbo plumbing. The engine itself is strong; it's the peripherals that cost. Budget for them.

5.0L V8 SC — coolant crossover pipe leaks, timing chain guide wear and supercharger isolator rattle. All three are known, and all three are worth addressing proactively. Oil changes within 10,000 miles are non-negotiable.

Used vs Reconditioned vs New L405 Engines: Which Should You Choose?

• Used Range Rover L405 engines: a lower-cost option, but the donor vehicle’s history matters. Ask for documented mileage, service and test results before choosing a unit.
• Reconditioned Range Rover L405 engines: ask for a written rebuilding specification showing which parts were inspected, machined or replaced. Confirm the warranty duration, exclusions and whether fitting labour is covered rather than relying on the word “reconditioned” alone.
• New: rarely necessary on an L405.

What Should You Check Before Buying an L405 Replacement Engine?

• Engine code confirmed (306DT, 448DT, AJ133)
• Service history — oil changes every 8,000–10,000 miles
• Timing chain status on SDV6 and V8
• Coolant pipework condition on the V8
• Warranty terms in writing
• Whether ancillaries are included

Can You Swap a TDV6 for an SDV6, SDV8 or V8?

Technically possible, but rarely sensible. Moving from a TDV6 to an SDV6 or V8 means ECU reprogramming, wiring modification and DVLA notification. In almost every case, replacing the original engine with an identical, updated unit is cheaper and far less trouble.

How Can You Avoid Overpaying for an L405 Engine Replacement?

1. Buy the variant you actually need — the TDV6 remains the value choice.
2. Compare on identical scope, including ancillaries.
3. Confirm VAT, delivery and fitting are inside the number.
4. Check the warranty — 12 months on a reconditioned unit is the benchmark.
5. Insist on service and chain evidence on any used or rebuilt unit.

Three habits protect your money. First, buy the variant you actually need rather than the one with the biggest numbers. Second, compare quotes on identical scope, with ancillaries and warranty stated. Third, buy history — documented servicing and, where relevant, documented chain and cooling work.

Do those three and the L405 becomes a manageable, even enjoyable, ownership proposition rather than a financial hazard.

Which Range Rover L405 Engine Should You Buy?

If value matters most, the answer is the 3.0L TDV6. One turbo, fewer failure points, and the lowest fitted replacement cost at £5,400–£7,200. It's the engine that lets you own an L405 without dreading the bill.

The SDV6 tempts with more power (296–306 bhp), but it adds a second turbo and a set of known weaknesses — timing chain on pre-2014 cars, turbo actuators, swirl flaps. If you buy one, buy it with documented oil changes and chain evidence.

The SDV8 is the towing specialist, rated to 3,500 kg. Durable mechanically, but peripherals cost more to fix and it drinks fuel. Buy it if you genuinely need the capacity.

The 5.0L V8 Supercharged is the flagship — 503–557 bhp — and the most expensive to keep. Its expenses are known: coolant crossover pipes, timing chain guides, supercharger isolator. Budget for proactive maintenance, not reactive repairs.

How Do You Compare L405 Engine Quotes Like for Like?

When comparing Range Rover L405 engines for sale, put every quote into one shape: engine code, condition (used or reconditioned), which faults were addressed, which ancillaries are included, warranty length, and whether VAT, delivery and fitting are inside the number. Matching the scope makes it easier to spot an incomplete quote.

What Should You Do in the First 48 Hours After L405 Engine Failure?

• Stop driving if the engine is overheating or noisy — damage compounds
• Get the fault diagnosed in writing
• Confirm the engine code (306DT, 448DT, AJ133)
• Check the service history for oil intervals
• Value the vehicle before you start looking at quotes

Final Verdict: Choosing an L405 Engine for Your Needs and Budget

Engine choice on an L405 is really a choice about ownership style. Want the lowest risk and lowest replacement cost? The TDV6. Want more pace and accept more maintenance? The SDV6. Need to tow seriously? The SDV8. Want the flagship experience with the flagship bills? The V8.

Whichever way you go, the money-saving habits are the same: buy documented history, compare identical scopes, include the ancillaries, and insist on a warranty that means something. Do that and an L405 engine replacement is an expensive but rational decision rather than an open-ended risk.

Range Rover L405 Engine FAQs

Which L405 engine is most reliable?

The 3.0L TDV6 (306DT single turbo) is widely considered the most durable, provided it's serviced every 10,000 miles.

How much is an L405 engine replacement?

£5,400–£7,200 fitted for the 3.0L diesels, £7,000–£9,000+ for the SDV8, and £8,000–£12,000+ for the 5.0L V8.

What should I avoid?

High-mileage SDV6 units with incomplete service history — twin-turbo wear compounds quickly when oil changes are missed.

Can I fit a different engine to my L405?

It's possible but rarely cost-effective; it needs ECU work, wiring changes and DVLA notification.

Should I compare quotes?

Yes. Compare L405 replacement engine quotes alongside the rebuild or donor history, included ancillaries and written warranty terms. Ask whether the price is supplied only or includes fitting.

Compare Range Rover L405 Replacement Engine Quotes

Ready to compare Range Rover L405 engine quotes? Enter your registration and engine code, then specify whether you want a used or reconditioned unit and whether fitting is required. Ask UK suppliers to confirm compatibility, availability, included parts and warranty terms in writing.

Get free Range Rover engine quotes and compare prices, fitting scope and warranty terms before you decide.