✔ Oil Pressure Restored Running Perfectly

TDV6 Crankshaft Failure: Complete Repair Case Study

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Make: Land Rover

Model: Discovery 4 (L319)

Engine: 306DT / TDV6 3.0L V6 Turbodiesel

Mileage: 142,000 miles

Symptom: Cold-start knock, low oil pressure warning

Prior Diagnosis: "Needs a new engine"

Duration: 4–5 working days (inc. machining)

Warranty: 12-Month Unlimited Mileage

When this Discovery 4 arrived with a cold-start knock and low oil pressure warning, a generalist garage had already condemned the engine. Through precise diagnosis and our dedicated TDV6/SDV6 crankshaft repair service, we restored oil pressure to 2.1 bar at hot idle—saving the owner thousands versus a replacement engine.

Recognise These TDV6 Symptoms?

We've just rebuilt this exact engine. Skip the diagnostic guesswork — get a fixed price for your 306DT.

No deposit required. Quote valid 30 days. Pricing disclaimer.

How This TDV6 Crankshaft Failure Presented

The vehicle presented with a deep, rhythmic knocking noise on cold start that had been worsening over three weeks. Crucially, the low oil pressure warning light was now illuminating at hot idle—a definitive sign of advanced bearing wear. Despite this, there was no visible metal debris in the oil filter, indicating an early-stage catch before catastrophic material shedding occurred.

The customer had been told by a previous garage that the engine "needs replacing entirely." This case demonstrates why that advice is often premature for the 306DT platform when caught at this stage.

What This Wasn’t (Common Misdiagnosis)

Generalists frequently misdiagnose TDV6 crankshaft failure as turbo bearing wear, injector knock, or timing chain rattle. Turbo shaft play was within spec; timing chain silent. Only mechanical oil pressure testing combined with end float measurement definitively confirms crankshaft/bearing wear before costly strip-down or unnecessary turbo replacement.

Root Cause Identification

Following DVSA MOT Inspection Manual Section 8.1.1 guidance on excessive crankshaft end float as a major defect, we performed comprehensive mechanical diagnostics before any disassembly:

Borescope Inspection: No cylinder liner damage or scoring visible.
Mechanical Oil Pressure Test: 0.6 bar at hot idle (FAIL — below 1.2 bar minimum).
SDD Diagnostic Scan: Fault code P0524 stored (oil pressure below threshold).
Crankshaft End Float: 0.31mm measured via dial gauge (FAIL — exceeds 0.07–0.17mm OEM limit by nearly 2×).

These findings confirmed spun main bearings as the root cause, consistent with JLR TSB SSM50892 diagnostic procedures for TDV6/SDV6 bottom-end noise.

Precision Repair Procedure

The repair followed a strict forensic-grade rebuild protocol aligned with both manufacturer and regulatory standards:

Engine Removal & Strip-Down: Full extraction and separation from transmission. Complete disassembly to bare block.
Crankshaft Measurement: Main journals measured at 68.71mm (below 68.960mm standard minimum). Confirmed regrind viability.
CNC Regrinding: Crankshaft reground to –0.25mm undersize per PSA Service Bulletin B1EP0QXA tolerances. Final journal diameter: 68.720mm (PASS).
Ultrasonic Block Cleaning: All oil galleries and bearing surfaces cleaned to remove microscopic debris.
Reassembly with OEM Parts: Kolbenschmidt 77891600 undersize bearings fitted. Mandatory new oil pump LR013589 installed per TSB SSM50892. Elring PTFE seals fitted using dedicated installation tools.
Post-Build Verification: Mechanical oil pressure test at hot idle: 2.1 bar (PASS). SDD fault codes cleared. Road test completed successfully.

This methodology mirrors the approach used in our L322 TDV8 crankshaft rebuild, adapted for the V6 architecture.

OEM Parts Used in This Repair

Component	OEM Part Number	Manufacturer	Notes
Main Bearing Set (Std)	77890600	Kolbenschmidt (KS)	OEM supplier for PSA/Ford/JLR V6 diesel
Big End Bearing Set	77891600	Kolbenschmidt (KS)	Undersize 0.25mm — used after regrind
Oil Pump Assembly	LR013589	Land Rover Genuine	Mandatory replacement on ALL TDV6 rebuilds
Crankshaft Seal (Front)	LR003888	Elring	Updated PTFE seal design
Crankshaft Seal (Rear)	LR003889	Elring	Must be fitted using installation tool
Head Gasket Set	LR010789	Victor Reinz	Includes valve stem seals
Timing Chain Kit	INA 559 0139 10	INA / Schaeffler	Upgraded tensioners included
Sump Gasket	LR002638	Land Rover Genuine	RTV silicone alternative acceptable

All parts cross-referenced against VIN. OEM or OEM-grade depending on availability, per our pricing disclaimer.

What This TDV6 Repair Cost — Transparent Breakdown

Labour Rate Disclosure: Labour charged at £70–£100/hr depending on complexity. This job used £80/hr rate for all 18 hours due to TDV6 rear-mounted oil pump access and CNC regrind coordination.

Phase	Hours	Cost	Notes
Diagnosis	2	£160	Oil pressure test, end float, SDD scan
Engine R&R	6	£480	Removal, separation, cradle access
Rebuild & Machining	8	£640	Strip, crank regrind coord, reassembly
Testing & Verification	2	£160	Multi-RPM oil pressure, road test
Total Labour	18	£1,440

Cost Line	This Job	Typical Range	Notes
Labour (18 hrs)	£1,440	£1,260–£1,800	Phased breakdown above
Crankshaft Regrinding	£280	£220–£350	Outsourced CNC grinding
Parts — Bearings + Seals	£385	£340–£480	KS, Elring components
Parts — Oil Pump LR013589	£195	£175–£240	Mandatory replacement
Parts — Timing Chain Kit	£310	£265–£390	Preventive measure
Parts — Gasket Set	£145	£120–£190	Victor Reinz complete set
Ultrasonic Block Cleaning	£120	£90–£150	Flat rate workshop overhead
Subtotal (ex. VAT)	£2,875	£2,470–£3,600
VAT (20%)	£575	£494–£720
Total (inc. VAT)	£3,450	£2,964–£4,320	Most jobs £3,200–£3,800

Pricing Disclosure: The figures shown represent the actual cost of this specific repair. Your quote will vary based on crankshaft condition at strip-down, parts availability at time of order, and any additional findings during disassembly. We provide a fixed price after initial diagnosis — not before. No deposit is required. All prices include VAT at 20%. See our full pricing disclaimer and 12-month unlimited mileage warranty terms.

💡 Value Context: A replacement JLR-remanufactured 306DT long engine carries a typical retail cost of £4,800–£7,500 plus 8–12 hours fitting. This crankshaft regrind — where the block and heads are serviceable — delivered a like-new result at approximately 45–55% of that cost.

Why This Repair Won't Fail Again

This rebuild addresses the root lubrication failure, not just the symptoms. The upgraded oil pump (LR013589) prevents recurrence of oil starvation. Every bearing was measured pre-fit with a micrometer—not assumed. Ultrasonic cleaning ensures zero debris remains in oil galleries. Backed by our 12-month unlimited mileage warranty and documented photo evidence.

We also replaced the timing chain kit as a preventive measure—a failure mode we cover in detail in our SDV6 timing chain case study. For owners outside Essex, we offer insured nationwide collection from £70.

Learn more about our full engine rebuilding process.

TDV6 Crankshaft Failure — Frequently Asked Questions

Can a TDV6 crankshaft be reground, or does it always need replacing?

In the majority of TDV6 cases where failure is caught early, the crankshaft can be precision reground to an undersize specification (typically –0.25mm) and returned to service with undersize Kolbenschmidt bearings. Replacement is only necessary when journals are beyond the regrind limit, cracked, or where catastrophic failure has damaged the block.

What does a spun main bearing sound like on a TDV6?

A spun main bearing typically presents as a deep, rhythmic knocking from low in the engine — most pronounced on cold start and at idle. On the TDV6 it often worsens progressively over days or weeks before the low oil pressure warning activates. By the time the warning light appears, bearing wear is confirmed.

How long does a TDV6 crankshaft repair take?

From collection or drop-off to completion, a TDV6 crankshaft regrind and rebuild typically takes 4–5 working days, including engine removal, disassembly, CNC regrinding, ultrasonic block cleaning, reassembly, and post-build oil pressure testing.

Is it worth repairing a TDV6 engine with crankshaft failure, or should I replace the vehicle?

For a structurally sound Discovery 4 or Range Rover Sport L320, a crankshaft regrind at approximately £3,000–£4,000 is almost always the economically rational choice versus a £4,800–£7,500 replacement engine. If the failure is caught before catastrophic liner or journal damage, a rebuild restores the engine to manufacturer specification.

Recognise These TDV6 Symptoms?

We've just rebuilt this exact engine. Skip the diagnostic guesswork — get a fixed price for your 306DT.

No deposit required. Quote valid 30 days. Pricing disclaimer.

Related Repairs & Case Studies

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L322 TDV8 Crankshaft Failure

Range Rover L322 3.6 TDV8 with main bearing failure. Full crank regrind, undersize bearings, and oil pump replacement — same methodology, V8 application.

See L322 TDV8 crankshaft rebuild →

Running Perfectly

SDV6 Timing Chain Failure

Discovery 4 SDV6 with timing chain rattle and jumped timing. Full chain kit replacement with upgraded INA tensioners. Related failure type on the same engine family.

See SDV6 timing chain rebuild →

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Our dedicated crankshaft regrind and bearing replacement service for all JLR 306DT and 306D1 diesel engines. Fixed quote after diagnosis. Nationwide collection available.

View our crankshaft repair service →