The 2009 Chrysler 300 is a solid platform with a few well-documented weak spots, particularly in the transmission cooling system and 2.7L V6 engine longevity. The NAG1 5-speed automatic transmission is generally robust, but supporting components cause headaches.
Transmission Oil Cooler Failure / Coolant Contamination
Common · high severityTypical onset: 80,000-140,000 mi
Symptoms: Pink or milky fluid on transmission dipstick (coolant mixing with ATF), Transmission slipping, delayed engagement, or erratic shifting, Overheating transmission, burnt fluid smell, Check engine light with transmission temp codes
Fix: Replace transmission oil cooler (internal to radiator on most models), flush transmission and cooling system completely, replace ATF and filter. If contamination sat too long, transmission rebuild may be necessary. Labor: 3-5 hours for cooler/flush, 12-18 hours if trans needs rebuild.
Estimated cost: $800-1,200 for cooler replacement and flush; $2,500-4,000 if transmission rebuild required
2.7L V6 Engine Sludge and Oil System Failures
Common · high severityTypical onset: 90,000-130,000 mi
Symptoms: Engine ticking or knocking from valve train or bottom end, Low oil pressure warning light, especially at idle when hot, Excessive oil consumption (1 qt per 1,000 mi or worse), Check engine light with cam/crank correlation codes, Catastrophic failure: rod knock, seized engine
Fix: The 2.7L has narrow oil passages prone to sludging even with regular changes. Once damage starts, you're looking at short block replacement (minimum) or full engine swap. Labor: 14-20 hours for engine R&R. Many shops recommend replacing with 3.5L V6 instead of rebuilding 2.7L.
Estimated cost: $3,500-6,500 for used/rebuilt engine installed; $2,000-3,500 if you catch it early and can rebuild in-place
Front Lower Control Arm Bushings and Ball Joints
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Clunking from front end over bumps, Wandering or loose steering feel, Uneven tire wear on inside edges, Vehicle pulls to one side, alignment won't hold
Fix: OEM control arm bushings fail prematurely. Most shops replace entire control arms (ball joint is integrated on many). Do both sides at once. Labor: 3-4 hours for both lower control arms, add alignment. HEMI and SRT8 models wear these faster due to weight.
Estimated cost: $600-1,000 for both sides with alignment
EVAP System Leaks and Purge Valve Failures
Occasional · low severityTypical onset: 60,000-100,000 mi
Symptoms: Check engine light with P0456 (small EVAP leak) or P0457 (loose gas cap), Difficulty fueling (pump keeps clicking off), Fuel smell around vehicle, especially after sitting in sun, Rough idle or stalling after refueling
Fix: Common failure points: EVAP purge solenoid, leak detection pump (LDP), and vapor canister vent valve. Smoke test to locate leak. Purge valve is easy (1 hour), LDP or canister requires dropping fuel tank (3-4 hours).
Estimated cost: $200-400 for purge valve; $500-900 for LDP or canister replacement
Rear Differential Pinion Seal Leak (V8 Models)
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Gear oil dripping from front of differential at driveshaft connection, Oil spots under rear center of vehicle, Whining or howling from rear end if fluid level drops significantly, Burnt gear oil smell
Fix: Pinion seal fails on 5.7L and 6.1L V8 rear diffs. Requires removing driveshaft, pinion nut, pinion flange. Critical: must set pinion preload correctly on reassembly or you'll destroy bearings. Labor: 2-3 hours.
Estimated cost: $300-550
Window Regulator Failures
Common · low severitySymptoms: Window drops into door suddenly or won't stay up, Grinding or clicking noise when operating window, Window moves slowly or gets stuck partway, One-touch auto feature stops working
Fix: Plastic rollers in regulators crack and disintegrate. Front windows fail more often than rears. Must remove door panel. Labor: 1.5-2 hours per door. Use OEM or quality aftermarket; cheap regulators fail in under a year.
Estimated cost: $250-400 per window
Tipm (Totally Integrated Power Module) Glitches
Occasional · medium severitySymptoms: Fuel pump relay sticking (no start, then starts after trying multiple times), Wipers running on their own or not working at all, Horn inoperative or honking randomly, Various electrical gremlins: gauges failing, accessories cutting out, Codes stored but symptoms intermittent
Fix: The TIPM (fuse/relay box) has notorious internal relay failures, especially fuel pump relay. Chrysler redesigned it mid-production. Replacement is plug-and-play but programming required. Labor: 2-3 hours including programming. Some independent rebuilders re-solder internal connections as cheaper alternative.
Estimated cost: $500-900 for reman TIPM; $200-400 for rebuild service
Buy a 3.5L V6 or 5.7L HEMI with service records and skip any 2.7L; otherwise a decent used buy if you can handle the transmission cooler issue proactively.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.