The E65 was BMW's most technologically ambitious 7 Series, and the 730d pairs the robust M57 inline-six diesel with the car's complex electronic architecture. The M57 engine itself is one of BMW's strongest, with many examples exceeding 300,000 km, but the E65 platform surrounding it brought first-generation iDrive, numerous electronic modules, and luxury features that age unpredictably. Facelift models (2005+) addressed many early electronic glitches and offer a noticeably improved ownership experience.· more· less
Durable M57 inline-6 dieselFacelift fixed many early issues
Complex electronics age poorlySpecialist knowledge essential
Buy if: You want a powerful diesel luxury sedan and can find a 2005+ facelift model with full specialist service history and healthy electronics.
Avoid if: You want predictable running costs, are looking at a pre-facelift model (2002-2004), or cannot access a BMW specialist familiar with E65 systems.
Metal swirl flaps in the intake manifold can break off and be ingested into the engine · more· less
The M57 intake manifold contains small metal swirl flaps designed to improve low-speed combustion. Over time, the plastic bushings holding these flaps degrade, and the flaps can break loose. If a flap fragment enters a cylinder, it can score the bore, damage pistons, and bend valves. Preventive removal with aluminium blanking plates costs around €200-400 and is the standard recommendation for any M57. If a flap has already been ingested, engine damage can require a partial rebuild costing €3,000-5,000. Pre-facelift models (M57N, 22mm flaps) and facelift models (M57N2, 33mm flaps) both require this fix. Many well-maintained cars will already have this done.
ZF 6HP26 transmission valve body wear
€800 - 3,5002 of 9
Valve body solenoids and seals degrade without regular fluid changes, causing harsh shifts and slipping · more· less
BMW marketed the ZF 6HP26 as a sealed-for-life unit, but ZF's own guidance for LifeguardFluid 6 is an oil change after 150,000 km, with a shorter interval where the car is used hard or its history is unknown, so a car with no transmission service record deserves one regardless of mileage. Cars that have never had a transmission service commonly develop shifting delays, harsh engagement from park to drive, and occasional slipping. The mechatronic sleeve seal between the valve body and case can fail, leading to pressure loss and accelerated clutch wear. A valve body rebuild with new solenoids costs approximately €800-1,500 at a specialist. If clutch packs are already damaged, a full transmission rebuild runs €2,500-3,500. Regular servicing (approximately €400-500) greatly extends transmission life.
Turbocharger failure (GT2260V / GT2260VK)
€1,500 - 3,0003 of 9
Variable geometry turbo can fail from oil starvation or carbon buildup, causing power loss and smoke · more· less
The variable geometry turbo on the M57, a GT2260V on the 218 hp car and a GT2260VK (758351) on the 231 hp version from 2005, is generally durable, but oil supply line restrictions and carbon buildup on the VNT mechanism can cause issues, particularly on cars used predominantly for short trips. Symptoms include black smoke under load, power loss, and turbo whistle changes. A remanufactured turbo unit costs approximately €800-1,200, with labor adding €500-800 due to accessibility in the E65 engine bay. Replacement with a new OEM unit can reach €2,500-3,000 installed. Allowing proper cool-down after hard driving and regular oil changes help prevent premature failure.
iDrive control unit and navigation computer failure
€400 - 1,5004 of 9
First-generation iDrive system freezes, reboots, or fails entirely, affecting navigation, radio, and climate · more· less
The E65 was BMW's first car with iDrive, and its early multimedia electronics are notorious for failures. Unlike later BMWs it has no single CCC or CIC head unit: the work is split across the ASK audio system controller, a separate navigation computer (NAVI01, NAVI02 or NAVI03 depending on build) and a separate tuner, so a fault has to be traced to the right module before any quote makes sense. Common symptoms include screen freezing, random reboots, navigation lock-ups, radio cutting out, and complete black screens. The DVD drive laser in the navigation computer degrades over time. Pre-facelift cars (2002-2004) are most affected. Repair options range from specialist refurbishment of the failed module (€400-600) to used replacement units (€500-800). A new BMW dealer replacement with programming can cost €1,200-1,500. The 2005+ facelift improved the system significantly, though it still ages.
EGR valve and cooler fouling
€500 - 1,2005 of 9
EGR valve clogs with soot, causing poor running, increased fuel consumption, and failed emissions tests · more· less
The M57 diesel EGR system accumulates carbon deposits over time, particularly on cars driven predominantly in urban traffic or on short trips. A clogged EGR valve causes rough idling, poor throttle response, and increased DPF regeneration frequency. Cleaning may provide temporary relief, but replacement is typically necessary. An EGR valve replacement costs approximately €500-800 including labor. If the EGR cooler has also failed (causing coolant contamination), the combined repair reaches €900-1,200. Regular motorway driving helps keep the system cleaner.
DPF clogging (facelift models)
€800 - 2,0006 of 9
Diesel particulate filter blocks on short-trip cars, triggering frequent regeneration or warning lights · more· less
Facelift models (2005+) came with a DPF as standard for Euro 4 compliance. Short-trip driving prevents proper regeneration, causing the filter to clog. Forum reports show some E65 730d owners experiencing regeneration cycles as frequently as every 50-100 miles when the system is struggling. Professional cleaning costs approximately €300-500, while a replacement DPF costs €1,200-2,000 fitted. Faulty back-pressure sensors can also trigger excessive regeneration. Pre-facelift models without a factory DPF do not have this issue. Cars driven regularly at motorway speeds typically do not experience problems.
Glow plug module and wiring damage
€300 - 8007 of 9
Glow plug control module fails or burns connector pins, causing difficult cold starts and white smoke · more· less
The glow plug control module (made by BERU) manages pre-heating for cold starts. The module and its wiring are prone to heat-related degradation, with burnt connector pins being a well-documented issue on E65 730d forums. The supply cable from the alternator should be replaced whenever the module is renewed due to poor connection issues. The module itself costs approximately €100-200 for the part. Individual glow plugs can seize in the head and snap during removal, adding significant labor cost. Total repair including module, plugs, and wiring typically runs €300-800 depending on whether glow plugs cooperate during removal.
CAS module failure (no-start condition)
€400 - 1,0008 of 9
Car Access System module develops dry joints or relay failure, preventing engine start · more· less
The E65 was the first BMW to use the CAS (Car Access System) module, located under the steering column. It controls starting, anti-theft, and vehicle coding. CAS1 modules (2001-2005) can develop internal dry solder joints or starter relay failure, leading to intermittent no-start conditions. The key may be recognized but the engine refuses to crank. Specialist repair of the circuit board costs approximately €200-400. A replacement module with programming runs €600-1,000. CAS issues can also cause false alarm triggers and central locking malfunctions.
Soft-close door mechanism failure
€300 - 6009 of 9
Door pull-in motors wear out, causing doors not to latch properly or appear shut when not fully closed · more· less
The E65 features soft-close doors on most variants, using small electric motors to pull the door into its final latching position. These motors wear out over time, resulting in doors that do not close completely or require manual slamming. The driver's door is typically affected first due to higher usage. A replacement actuator costs approximately €150-250 per door, with labor around €100-150 per door.
Robust engine let down by complex electronics and aging luxury features
The M57 diesel engine in the 730d is one of the most durable units BMW has produced, with many exceeding 300,000 km without major issues. However, the E65 platform surrounding it is among BMW's most electronically complex, and these systems age unpredictably. The iDrive, CAS module, soft-close doors, and optional air suspension all represent potential failure points that do not exist on simpler BMWs. Facelift models (2005+) are meaningfully more reliable than pre-facelift cars. A thorough specialist inspection and complete service history are essential before purchase.
Service history
Complete BMW dealer or specialist records essential. Verify oil changes every 15,000 km or annually. Check for a ZF transmission fluid change; ZF's interval for LifeguardFluid 6 is 150,000 km, shorter under hard use.
Tires
Check tread depth, age (date codes on sidewall), and uneven wear patterns. E65 uses 245/50R18 or similar large sizes.
Cold start
Must start the engine completely cold. Listen for any unusual rattles, knocking, or extended cranking. Watch for white/blue smoke indicating glow plug or injector issues.
Test drive
Minimum 30 minutes including motorway speeds. Monitor all dashboard warnings and check that all electronics function correctly.
Specific for this vehicle
Check if swirl flaps have been blanked or removed
Ask the seller directly. If not done, budget €200-400 for preventive blanking. This is the single most important check on any M57.
Test all iDrive functions thoroughly
Navigate through every menu, test navigation, radio, CD player, and climate controls. Watch for freezes, reboots, or black screens during the test drive.
Check transmission behavior when cold and hot
Drive for at least 20 minutes. Feel for delayed engagement from park to drive, harsh shifts between gears, or any slipping. Ask when fluid was last changed.
+ 4 more checksShow less
Test every door soft-close mechanism
Gently push each door almost closed and listen for the pull-in motor. All four doors plus boot lid should pull shut automatically.
Look for oil leaks at the oil filter housing and vacuum pump
These are the usual oil leak points on the M57. Check the front of the engine around the filter housing and the rear of the cylinder head where the tandem vacuum pump sits, and look for residue on the underbody.
Verify pre-facelift vs facelift (LCI) status
Facelift models (2005+) have revised headlights, improved iDrive, and are significantly more reliable. Production date is on the door jamb sticker.
Check DPF regeneration behavior (facelift models)
On facelift cars, ask about DPF warning lights. Check oil level which rises if excessive DPF regeneration dilutes oil with diesel.
Recalls and Technical Service Bulletins
Defective Bosch high pressure diesel injection pump fitted from December 2004 (European campaign of February 2005, roughly 21,500 BMW diesels worldwide including about 6,000 in Germany)Verify completed
Contact a BMW dealer with the VIN to confirm the high pressure pump campaign was carried out; it reaches only cars built from December 2004. Campaigns that are often listed against the E65 but do not belong to this car: the door latch action and the rollaway action are BMW of North America recalls for petrol models such as the 745i, 750i and 760i, and the Takata airbag campaign excludes the E65 and E66, whose original inflators were supplied by Autoliv.
Warranty Status
Factory warranty (2 years)Expired on all E65 models
Rust perforation warranty (12 years)Expired on all E65 models
Extended warranty availabilityGenerally unavailable due to age
All BMW E65 730d models are well outside their original 2-year factory warranty and 12-year rust perforation warranty. Third-party warranty providers may offer coverage but typically exclude electronics and pre-existing conditions, which limits their usefulness on an E65.
Sources: Research draws on model-specific owner forums and owner communities, recall information from official authorities, German automotive press, and multiple workshop cost references cross-checked against each other.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.
