42LE Automatic Transmission Failure
high- Typically appears
- 80–130k mi
- Estimated repair
- $1,800 – $3,500
2000 Chrysler
300MSedan
3.5L V6 · Sedan
The 2000 Chrysler 300M is a front-wheel-drive, full-size sport sedan built on Chrysler's LH platform — the same bones shared with the Dodge Intrepid and Chrysler Concorde. It was the performance flagship of the lineup, featuring a standard 3.5L V6 paired with a 4-speed automatic, sport-tuned suspension, and a more driver-focused interior than its siblings. The 300M carved out a niche as an affordable American alternative to European sport sedans, offering genuine highway composure and a distinctive cab-rearward stance. By 2000, the second-generation 300M (launched in 1999) was well-sorted. It was well-regarded for its interior space, smooth highway ride, and powerful V6 for the era. However, it carried the LH platform's known weaknesses — transmission reliability, electrical gremlins, and a tendency to develop suspension wear earlier than average. Parts availability has declined as the model ages, so ownership today requires some mechanical patience. As a 25-year-old vehicle, any surviving 300M should be evaluated carefully for rust (particularly in the upper Midwest), transmission condition, and electrical system health. With proper maintenance it can be a rewarding and stylish daily driver, but deferred maintenance is common on older luxury-adjacent vehicles and adds up quickly.
Reliability
2/5
Verified data
Engine
3.5L V6
Drivetrain
FWD
Fuel
Gasoline
MPG
17 city / 25 hwy / 20 combined
Seats
5
Doors
4
Body
Sedan
MSRP
$27,870
Overview
AI-curatedThe 2000 Chrysler 300M is a front-wheel-drive, full-size sport sedan built on Chrysler's LH platform — the same bones shared with the Dodge Intrepid and Chrysler Concorde. It was the performance flagship of the lineup, featuring a standard 3.5L V6 paired with a 4-speed automatic, sport-tuned suspension, and a more driver-focused interior than its siblings. The 300M carved out a niche as an affordable American alternative to European sport sedans, offering genuine highway composure and a distinctive cab-rearward stance. By 2000, the second-generation 300M (launched in 1999) was well-sorted. It was well-regarded for its interior space, smooth highway ride, and powerful V6 for the era. However, it carried the LH platform's known weaknesses — transmission reliability, electrical gremlins, and a tendency to develop suspension wear earlier than average. Parts availability has declined as the model ages, so ownership today requires some mechanical patience. As a 25-year-old vehicle, any surviving 300M should be evaluated carefully for rust (particularly in the upper Midwest), transmission condition, and electrical system health. With proper maintenance it can be a rewarding and stylish daily driver, but deferred maintenance is common on older luxury-adjacent vehicles and adds up quickly.
Known for
- Strong 3.5L V6 with good highway power
- Distinctive sport-sedan styling with a European feel
- Spacious, driver-focused interior for its class
- Smooth, composed highway ride on the LH platform
- Affordable entry price as an aging used car
Best for
- Highway commuters who want a comfortable full-size sedan
- Budget-conscious buyers who enjoy American sport sedans
- Owners who can handle their own basic maintenance
- Drivers who prioritize interior space and V6 power
Watch for
- Transmission (42LE) failure — a chronic LH platform weakness
- Electrical gremlins from aging body control modules and wiring
- Front suspension wear — lower ball joints and tie rod ends
- Rust on subframes, brake lines, and rocker panels in salt states
- Coolant system issues including thermostat housing and water pump leaks
Common issues by mileage
6 knownThermostat Housing / Coolant Leak
high- Typically appears
- 70–110k mi
- Estimated repair
- $200 – $500
Front Lower Ball Joint and Tie Rod Wear
high- Typically appears
- 60–100k mi
- Estimated repair
- $300 – $700
Body Control Module (BCM) / Electrical Gremlins
medium- Typically appears
- 80k+ mi
- Estimated repair
- $250 – $900
Power Window Regulator Failure
medium- Typically appears
- 70k+ mi
- Estimated repair
- $150 – $350
Instrument Cluster / Speedometer Malfunction
medium- Typically appears
- 80k+ mi
- Estimated repair
- $200 – $600
Maintenance schedule
- 1 Every 30,000 miles — do not skip on a used example Automatic Transmission Fluid Change
The 42LE transmission is fragile when fluid is degraded. If service history is unknown, change it immediately. Use the correct ATF+4 fluid only — the wrong fluid accelerates clutch pack wear.
- 2 Every 2 years or 30,000 miles Engine Coolant System Inspection and Flush
The 3.5L is prone to thermostat housing leaks and water pump weeping. Inspect hoses, housing, and reservoir cap at every flush. Use Mopar/OAT-compatible coolant — mixing types causes silicate dropout and clogs.
- 3 Every 60,000 miles or at signs of cracking/squealing Serpentine Belt and Tensioner Inspection
Belt failure on the 3.5L kills the water pump and alternator simultaneously. Replace the tensioner pulley at the same time — they wear together.
- 4 Every 30,000 miles or annually Front Suspension Inspection (Ball Joints, Tie Rods, Sway Bar Links)
Wisconsin roads and salt accelerate bushing and joint wear. A worn ball joint can cause sudden loss of steering control — don't defer this inspection.
- 5 Annually — critical on salt-state vehicles Brake Line Inspection
Steel brake lines on 25-year-old upper Midwest vehicles are a corrosion risk. Inspect the full line run for rust pitting or swelling. A failed brake line is a road safety emergency.
- 6 Every 30,000 miles Spark Plugs and Ignition Coil Inspection
The 3.5L V6 uses a coil-pack ignition system. Worn plugs cause misfires and can damage the catalytic converter. Rear bank plugs are harder to access — budget extra labor time.
- 7 Every fall before Wisconsin winter Battery Load Test
Cold cranking demand on a 25-year-old car with an aging electrical system is significant. A battery showing 60% or less capacity will likely fail in sub-zero temps. Replace proactively.
- 8 Every 2 years Power Steering Fluid Check and Flush
The 300M uses a hydraulic rack-and-pinion. Old fluid breaks down seals and causes rack leaks that are expensive to repair. Keep fluid clean and check for wetness around the rack boots.
Always defer to the manufacturer's service manual for warranty-mandated intervals.
Cost of ownership
Annual maintenance
$900 – $2,200
Fuel
At 20 MPG combined and ~12,000 miles/year, expect roughly $1,500–$1,800/year at current Midwest gas prices. Premium fuel is not required — regular 87 octane is acceptable.
Insurance
Generally low — older full-size sedans with low market value carry minimal collision premiums. Expect $600–$1,100/year for a typical driver in the Lake Geneva area depending on coverage level.
The 300M is cheap to buy but carries real ownership risk. Routine maintenance runs $900–$1,200 in a good year. If the transmission or major electrical components need attention, a single repair event can easily hit $2,000–$3,500. Budget for a transmission fluid service immediately if history is unknown, and set aside a repair fund. The car's low market value means repair costs can quickly exceed the vehicle's worth — know your exit number before you sink money into it.
Seasonal care
Lake Geneva, WI Winter
- Load-test the battery every October — sub-zero temps will expose any weakness in an aging 12V system. Replace if capacity is below 75%.
- Switch to a full-synthetic 5W-30 oil if not already using one — conventional oil thickens in sub-zero starts and increases wear on cold cranking.
- Inspect brake lines and fuel lines for rust damage before winter. Salt brine on Wisconsin roads accelerates corrosion on 25-year-old steel lines.
- Use a winter-rated windshield washer fluid rated to at least -25°F. The reservoir and lines on this era of Chrysler products are prone to cracking if water-diluted fluid freezes.
- Check that the coolant mixture is at least 50/50 antifreeze-to-water — a 25-year-old cooling system may have been topped off improperly over the years.
- Apply undercarriage anti-rust spray or fluid film to the subframe, suspension components, and brake line runs before first snowfall.
Summer
- Inspect the A/C system — R-134a systems this age often have slow refrigerant leaks from dried o-rings. Have it pressure-checked before summer heat arrives.
- Check tire pressure monthly — ambient temperature swings of 40°F+ between Wisconsin spring nights and summer days can cause 4–6 PSI swings.
- Inspect the cooling system for heat soak symptoms: watch for the temp gauge climbing in traffic. A slow-leaking thermostat housing or weak water pump shows itself fastest in summer.
- Check the power steering reservoir — heat causes old fluid to oxidize faster, and a leaking rack seal will worsen with high underhood temps.
Comparable vehicles
2000 Dodge
Intrepid
Same LH platform, same 2.7L or 3.5L V6 options, lower price point. Shares most mechanical components with the 300M. Less sporty styling but virtually identical ownership experience.
2000 Ford
Taurus
Competitive full-size FWD sedan from the same era. More reliable overall, especially the Vulcan V6. Less exciting to drive but significantly better long-term ownership record.
2000 Pontiac
Bonneville
GM's full-size sport sedan answer. The 3800 V6 is one of the most proven engines of the era — more reliable than the 300M's drivetrain, with a similarly spirited driving character.
2000 Toyota
Avalon
Toyota's full-size V6 sedan. Far superior long-term reliability, though less sporty. If low hassle ownership matters more than driving character, the Avalon is the smarter pick at similar used prices.
If you're shopping for one
Red flags
- Any transmission slip, shudder, or rough shifting — walk away unless the price reflects a full rebuild.
- Rust on the subframe or brake lines — structural rust in Wisconsin cars can make a vehicle unsafe and uneconomical to repair.
- Check engine light with multiple stored DTCs, especially U-series network codes — complex electrical faults on a 25-year-old Chrysler product can be a money pit.
- Visible coolant residue or white staining around the thermostat housing or radiator hoses — indicates an active or recent leak.
- Evidence of overheating history (white residue inside the oil cap, milky oil, bubbling in the coolant reservoir) — head gasket damage is costly on this engine.
- No maintenance records — given the transmission's known fragility, an undocumented service history is a significant financial risk.
What to inspect
- Test drive at highway speed and check for transmission shudder, slipping between gears, or delayed engagement — these signal imminent 42LE failure.
- Check underneath for rust on the subframe, brake lines, and fuel lines — critical on any car that has lived in Wisconsin or surrounding salt states.
- Pull the transmission dipstick: fluid should be pink-red and smell clean. Dark brown or burnt-smelling fluid means the transmission has been neglected.
- Check all four power windows — regulators are a known failure point and replacement motors/regulators are increasingly hard to source.
- Start the car cold and watch the temperature gauge — it should climb to the center mark and hold steady. Overheating or erratic temp behavior indicates coolant system issues.
- Scan for stored DTCs before purchase. U-series network codes can indicate BCM or wiring harness issues that are expensive and time-consuming to diagnose on a 25-year-old car.
- Inspect the front suspension by grabbing each front wheel at 9 and 3 o'clock and pushing/pulling — any clunking indicates worn tie rods or ball joints.