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2005 Mercedes-Benz SLK350

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By Research the Car 5 min read

The 2005 Mercedes-Benz SLK350 is a stylish and sporty roadster that offered a blend of luxury and performance. The SLK350 comes standard with a 3.5L V6 engine producing 268 horsepower and 258 lb-ft of torque. It was offered with either a 6-speed manual or a 7G-TRONIC 7-speed automatic transmission. Some owners appreciated its retractable hardtop, sporty handling, and luxurious interior, while others disliked its somewhat cramped cabin and potential for expensive repairs.

Engine

3.5L V6

  • Balance Shaft Sprocket Wear
    • Description/Symptoms: A common issue affects the M272 engine series, including the 3.5L V6 in the 2005 SLK350, especially those built before 2007. The balance shaft sprocket can wear prematurely due to the use of a softer metal. Symptoms include a check engine light (CEL) with codes P0016 and P0017, rattling noises from the engine, and rough idling.
    • Solution: Replacing the balance shaft requires extensive engine disassembly. Updated parts using a harder metal are available.
    • Estimated Cost to Fix: $3,000 - $6,000+
    • Recalls: None Found
  • Camshaft Adjuster Solenoid Failure
    • Description/Symptoms: The camshaft adjuster solenoids can fail, leading to poor engine performance, rough idling, and a check engine light.
    • Solution: Replacing the faulty solenoid(s).
    • Estimated Cost to Fix: $200 - $500+
    • Recalls: None Found
  • Valve Cover Gasket Leaks
    • Description/Symptoms: Oil leaks from the valve cover gaskets are common as the gaskets age. Symptoms include visible oil leaks on the engine and a burning oil smell.
    • Solution: Replacing the valve cover gaskets.
    • Estimated Cost to Fix: $300 - $600+
    • Recalls: None Found

Transmission

7G-TRONIC 7-Speed Automatic Transmission

  • Torque Converter Failure
    • Description/Symptoms: Torque converter failure can cause shuddering during acceleration, erratic shifting, and a loss of power.
    • Solution: Replacing the torque converter.
    • Estimated Cost to Fix: $1,500 - $3,000+
    • Recalls: None Found
  • Conductor Plate Failure
    • Description/Symptoms: The conductor plate within the transmission can fail, leading to incorrect gear selection, limp mode, and a check engine light.
    • Solution: Replacing the conductor plate and potentially the valve body.
    • Estimated Cost to Fix: $800 - $1,800+
    • Recalls: None Found
  • Slipping and Harsh Shifting
    • Description/Symptoms: Transmission slipping and harsh or erratic shifting. This can be caused by low fluid, valve body issues, or internal wear.
    • Solution: Transmission fluid flush and filter change. Valve body replacement or overhaul may be necessary. Complete transmission rebuild or replacement might be needed in severe cases.
    • Estimated Cost to Fix: $200 - $4,000+ depending on severity.
    • Recalls: None Found

Suspension

  • Ball Joint Failure
    • Description/Symptoms: Worn ball joints can cause clunking noises from the suspension, loose steering, and uneven tire wear.
    • Solution: Replacing the worn ball joints.
    • Estimated Cost to Fix: $300 - $800+ per side.
    • Recalls: None Found
  • Strut Mount Failure
    • Description/Symptoms: Deteriorated strut mounts can cause rattling noises, reduced handling precision, and increased wear on other suspension components.
    • Solution: Replacing the strut mounts.
    • Estimated Cost to Fix: $400-$1000+ per pair
    • Recalls: None Found

Electrical

  • SAM (Signal Acquisition Module) Failure
    • Description/Symptoms: The SAM module controls various electrical functions, and failure can lead to issues with lights, wipers, power windows, and other systems.
    • Solution: Replacing the faulty SAM module and programming it to the vehicle.
    • Estimated Cost to Fix: $800 - $2,000+
    • Recalls: None Found
  • Battery Drain
    • Description/Symptoms: Excessive battery drain can occur due to faulty modules or electrical components not shutting down properly.
    • Solution: Diagnosing and repairing the source of the battery drain, which may involve replacing a faulty module or component.
    • Estimated Cost to Fix: $100 - $1,000+ depending on the source.
    • Recalls: None Found
  • Retractable Hard Top Malfunctions
    • Description/Symptoms: Issues with the retractable hard top are common. These range from failure to open or close completely, to getting stuck mid-cycle. This is often attributed to hydraulic pump issues, sensor malfunctions, or problems with the latching mechanisms.
    • Solution: Diagnosis of the specific issue is required. Solutions can range from sensor replacement, hydraulic fluid top-up, pump replacement, or latch mechanism repair/replacement.
    • Estimated Cost to Fix: $200 - $3000+ depending on the issue.
    • Recalls: None Found

Exterior

  • Retractable Hard Top Seal Leaks
    • Description/Symptoms: Water leaks around the retractable hardtop seals can occur, especially as the seals age and deteriorate.
    • Solution: Replacing the worn seals or adjusting the top’s alignment.
    • Estimated Cost to Fix: $200-$1,000+
    • Recalls: None Found

Interior

  • Air Conditioning Failure
    • Description/Symptoms: Air conditioning stops blowing cold air or only blows hot air. Can be caused by refrigerant leaks, compressor failure, or a faulty blend door actuator.
    • Solution: Recharge the refrigerant, replace the compressor, or replace the blend door actuator.
    • Estimated Cost to Fix: $200 - $1,500+
    • Recalls: None Found
  • Heater Core Failure
    • Description/Symptoms: Heater stops blowing hot air or only blows cold air. May have a sweet coolant smell inside of the vehicle when running. Can be caused by a clogged heater core or a leak.
    • Solution: Replace the heater core.
    • Estimated Cost to Fix: $800 - $2,000+
    • Recalls: None Found

Summary

The 2005 Mercedes-Benz SLK350, while a desirable roadster, can suffer from a number of issues. The most concerning are related to the engine’s balance shaft, timing chain and the transmission. Electrical issues, particularly with the SAM module and retractable hardtop, are also relatively common. Suspension and smaller engine issues like oil leaks can also add to the maintenance costs. The severity and cost of these repairs can range from a few hundred dollars for minor fixes to several thousand dollars for major engine or transmission work. Potential buyers should be aware of these potential issues and have any prospective purchase thoroughly inspected by a qualified mechanic familiar with Mercedes-Benz vehicles.

Mercedes-Benz, SLK350
Mercedes-Benz SLK350 2005
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