2005 MERCEDES-BENZ SLK280 R171

Typical onset: 60,000-120,000 mi

Symptoms: Rattling noise from front of engine on cold start that disappears when warm, Metallic grinding or buzzing sound from timing cover area, Check engine light with camshaft position sensor codes, Sudden catastrophic failure: loss of power, severe knocking, metal shavings in oil

Fix: The plastic balance shaft gears strip teeth, drop debris into the timing case, and jam the timing chain. Once it grenades, you're looking at complete engine rebuild or replacement. Preventive fix requires removing timing cover, replacing both balance shaft gears with updated parts, new timing chain, rails, tensioner. 18-24 labor hours for preventive work, 35-50 hours for full engine rebuild after failure.

Estimated cost: $4,500-7,500 preventive, $12,000-18,000 post-failure rebuild

Typical onset: 80,000-150,000 mi

Symptoms: Cold start rattle for 2-3 seconds, Check engine light with multiple camshaft timing codes (P0011, P0021), Rough idle and reduced power, Metal debris in oil filter during changes

Fix: Independent of balance shaft issues, the M272 timing chains stretch and guide rails wear. Requires removing timing cover, replacing both chains, all guides, rails, tensioners, cam adjusters. Often done preventively when doing balance shaft work. 16-22 labor hours as standalone job.

Estimated cost: $3,500-5,500

Typical onset: 70,000-120,000 mi

Symptoms: Severe clunk when shifting from Park to Drive or Reverse, Vibration through chassis at idle in gear, Visible sagging of transmission when inspected from below, Exhaust heat shield rattles due to shifted transmission position

Fix: The hydraulic transmission mount fails, allowing excessive drivetrain movement. Must drop transmission slightly to replace mount. Common Mercedes problem, straightforward fix. 3-4 labor hours.

Estimated cost: $600-1,000

Typical onset: 90,000-140,000 mi

Symptoms: Rough idle and hesitation, Oil consumption increases noticeably, Oil leaks from valve cover or rear main seal area, Check engine light with lean/rich mixture codes

Fix: The M272 crankcase ventilation system clogs with carbon, causing pressure buildup and oil leaks. Requires intake manifold removal, cleaning/replacement of PCV valve and breather hoses, valve cover gaskets while you're there. 8-10 labor hours.

Estimated cost: $1,800-2,800

Typical onset: 80,000-130,000 mi

Symptoms: Red transmission fluid puddles under car, Low transmission fluid warning on dash, Harsh shifting or slipping if fluid level drops significantly, Visible corrosion on metal cooler lines at radiator connection

Fix: The metal transmission cooler lines rust through, especially at fittings. Replace both feed and return lines, flush cooler, refill transmission. 3-4 labor hours plus fluid.

Estimated cost: $800-1,400

Typical onset: Any age, rubber deterioration

Symptoms: Top operates slowly or hesitates mid-cycle, Visible oil weeping from cylinder seals at rear corners, Top fails to latch properly, Hydraulic pump runs longer than normal

Fix: The hydraulic cylinders that operate the top develop seal leaks. Can often rebuild cylinders with seal kits, but replacement is more reliable. Top mechanism must be partially disassembled. 6-8 labor hours per side.

Estimated cost: $1,200-2,200 both sides