An American full-size sedan with European underpinnings. The LX platform borrows heavily from the Mercedes W211 E-Class, and the 3.0 CRD uses the Mercedes OM642 V6 diesel paired with a Mercedes-derived NAG1 5-speed automatic. Sold in Europe from 2005 to 2010, it offered unusual presence and space for the money, though dealer support was always limited.· more· less
Oil mist from crankcase ventilation contaminates the electric swirl motor, causing limp mode · more· less
The OM642 engine uses electrically actuated butterfly valves (swirl flaps) in the intake manifold to control airflow. Oil vapour from the crankcase ventilation system condenses in the intake pipe and drips onto the swirl motor's circuit board, corroding it over time. When the motor fails, the car enters limp mode with severely reduced power and a 3,000 rpm cap. This is widely reported across all OM642 applications. Chrysler forums have extensively documented this as one of the most common CRD problems. A repair kit with a new motor costs around €150-300, and a full manifold replacement with labour can reach €800-1,200. A simple resistor emulator (around €20) can bypass the motor, though this is not an ideal long-term solution. Typically occurs between 80,000 and 150,000 km.
Oil cooler seal leak (valley leak)
€800 - 1,8002 of 9
Rubber seals in the engine valley harden and crack, causing pressurised oil leak · more· less
The OM642 has an oil cooler located in the V of the engine block (the valley), sealed with rubber O-rings. Over time, these seals harden from heat exposure and crack, causing oil to leak under pressure. Mercedes issued a Technical Service Bulletin for this in 2016, and updated seal kits (orange to purple seals) are available. The parts are inexpensive (€50-100 for a seal kit), but the repair requires approximately 8 hours of labour because the intake manifolds, turbo pipework, and various components above the valley must be removed for access. Independent specialist costs range from €800-1,200, while dealer-level labour pushes toward €1,500-1,800. Common on cars above 100,000 km. Oil pooling under the transmission or a burnt smell after shutdown are typical symptoms.
Turbo actuator or VGT vane failure
€500 - 2,5003 of 9
Variable geometry vanes stick from soot buildup, or the electronic actuator burns out · more· less
The turbocharger on the OM642 uses variable geometry turbine vanes to optimise boost across the rev range. Carbon and soot deposits can cause the vanes to stick, leading to either no boost (underboost with no power below 2,000 rpm) or uncontrolled overboost. The electronic actuator can also fail independently due to heat exposure, typically after 120,000 km. Actuator replacement alone costs around €500-900 at an independent specialist. If the turbine vanes are damaged or the turbo requires full replacement, costs rise to €1,500-2,500 including labour. Remanufactured turbos are available from around €400-600, keeping costs manageable if only the turbo core is needed.
DPF clogging
€500 - 1,5004 of 9
Diesel particulate filter clogs from short-trip driving, causing power loss and warning lights · more· less
Like all diesel cars of this era, the 300C CRD has a diesel particulate filter that requires regular highway driving to regenerate. Cars used predominantly for short urban trips are particularly susceptible. When the DPF clogs, the engine loses power and the check engine light illuminates (often with code P242F). The recommended replacement interval is 125,000-175,000 km, but city-driven cars can clog much sooner. Professional DPF cleaning costs around €300-500, while a full replacement with an aftermarket unit runs €600-1,000, or up to €1,500 with an OEM-spec filter and installation. A partially blocked DPF can also raise engine oil levels due to failed regeneration cycles.
EGR valve carbon buildup
€400 - 9005 of 9
EGR valve sticks from carbon deposits, causing rough idle and error codes · more· less
The exhaust gas recirculation valve accumulates carbon over time, particularly on cars that spend a lot of time in urban traffic. A sticking EGR valve causes rough idle, poor throttle response, and engine management warning lights. On the OM642 in the 300C, the EGR valve is located at the rear of the engine under the plastic cover, making access and diagnosis more difficult. Cleaning is sometimes possible but often the valve needs replacement. Part cost is approximately €150-250, with labour adding €250-400 due to accessibility. Cleaning costs around €150-200 if successful.
Alternator failure
€400 - 8006 of 9
Carbon brush debris accumulates inside the alternator due to a design weakness · more· less
The alternator on the CRD has a known design weakness where carbon dust from the brushes cannot escape the brush box properly. This creates a conductive paste on the slip rings that leads to reduced charging output or complete failure. Failures have been reported as early as 40,000 km on some cars. Symptoms include dimming dashboard lights, flickering HID headlights, battery warning light, and radios switching on and off randomly. Replacement with a new unit costs around €400-600 at an independent shop, or up to €800 at a dealer. Remanufactured alternators are available for around €200-300.
Glow plug module failure
€200 - 5007 of 9
Failed glow plug control module causes cold-start difficulties in winter · more· less
The glow plug control module can fail, preventing the glow plugs from heating properly before engine start. This is particularly noticeable in cold weather, where the engine may crank but refuse to fire. Fault codes P0671 through P0676 indicate individual glow plug circuit failures. The module itself costs approximately €100-200 and is relatively accessible for replacement. Individual glow plugs can also fail and should be inspected; a full set of six costs around €150-300 for parts. Combined replacement of module and all six plugs runs €200-500 depending on whether you use independent or specialist labour.
Lower control arm bushing wear
€400 - 9008 of 9
Front suspension lower control arm bushings wear quickly due to the car's weight · more· less
The 300C weighs approximately 1,900 kg, which places significant stress on the front suspension components. The lower control arm bushings are a known weak point on the LX platform, often wearing out by 60,000-80,000 km. Symptoms include squeaking or knocking sounds over bumps, and uneven tyre wear. On rough European roads, this can accelerate further. Replacement of both lower control arms (typically the bushings are not serviceable separately) costs approximately €400-600 per side including alignment. Upgraded polyurethane bushings are available for around €100-150 per side if pressing new bushings is preferred, though this requires access to a press.
Window regulator cable failure
€200 - 4009 of 9
Cable mechanism inside the door breaks, causing the window to drop or become stuck · more· less
The power window regulators use a cable mechanism that is prone to breaking, typically in the front doors after 70,000-100,000 km. The cable can snap or the regulator motor can fail, causing the window to drop into the door or become stuck in position. A replacement window regulator costs approximately €80-150 for the part, with around 1-2 hours of labour for installation. This is a well-documented issue across the LX platform with over 90 complaints recorded on NHTSA databases. Listen for grinding noises during window operation as an early warning sign.
Mercedes-derived drivetrain is solid, but Chrysler-specific parts are scarce
The 300C CRD benefits from the proven OM642 engine and NAG1 transmission, both of which can reach 300,000+ km with proper maintenance. However, the swirl motor, oil cooler seals, and turbo actuator are well-documented weak points across all OM642 applications. Chrysler-specific body, electrical, and interior parts can be difficult and expensive to source in Europe due to the car's rarity. An independent specialist familiar with the OM642 is strongly recommended over trying to use a Chrysler dealer network that barely exists in most European countries. Budget for ongoing diesel system maintenance and source a car with complete, verifiable service history.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete records from a specialist or independent garage essential. Verify oil changes every 12 months or 15,000 km with the correct 229.51 specification oil.
Tyres
Check tread depth, age (date codes on sidewall), and uneven wear patterns. Uneven front tyre wear can indicate worn control arm bushings.
Cold start
Must start the engine completely cold. Diesel should fire within 2-3 seconds of cranking after glow plug warm-up. Extended cranking suggests glow plug or module issues.
Test drive
Minimum 30 minutes including both urban and highway driving to check for limp mode, turbo response, and gearbox shifting quality.
Specific for this vehicle
Check for swirl motor fault codes
Scan with a diagnostic tool for P2006, P2007, or P2513 codes. If the car has been in limp mode, a resistor bypass may be installed. Ask the seller directly.
Inspect under the car for oil leaks
Look for oil pooling on the rear engine crossmember or transmission bell housing. Oil cooler valley leak will show oil seeping from between the cylinder banks.
Listen for turbo response and boost
During the test drive, accelerate firmly from low rpm. The turbo should spool smoothly by 2,000 rpm. Any hesitation, sudden power drop, or whistling noise suggests vane or actuator problems.
+ 4 more checksShow less
Check alternator charging voltage
With engine running, battery voltage should read 13.5-14.5V. Flickering dashboard lights or dimming headlights indicate alternator brush wear.
Test front suspension over bumps
Drive over speed bumps and uneven surfaces. Squeaking or knocking from the front indicates worn lower control arm bushings, a common issue on this heavy platform.
Operate all windows fully up and down
Listen for grinding or hesitation in the front door windows. Cable mechanism failure is common after 70,000 km.
Check engine oil level and colour
Unusually high oil level can indicate failed DPF regeneration cycles diluting oil with diesel fuel. Oil should be dark but not excessively thick or gritty.
Side repeater indicator warning telltale not functional (EU-market vehicles)Verify completed
Chrysler's European dealer network is largely dissolved. Contact FCA Heritage or a Chrysler specialist with the VIN to verify all recalls have been completed. The driver airbag inflator recall is the most critical safety item.
Warranty Status
Factory warranty (2 years)Expired on all used 300C models
Extended warrantyRarely available due to age and limited dealer support
All Chrysler 300C LX models are well outside their original 2-year factory warranty. Extended warranty options are extremely limited due to the car's age and Chrysler's minimal European presence. Independent specialist knowledge of the OM642 engine is more valuable than warranty coverage at this point.
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.
