2007 MERCEDES-BENZ SLK280 R171

Typical onset: 60,000-120,000 mi

Symptoms: Check engine light with cam/crank correlation codes P0016/P0017/P0018, rattling noise on cold start lasting 1-2 seconds, complete engine failure if timing jumps, metal shavings in oil

Fix: The plastic balance shaft sprocket strips teeth and damages the timing chain. Proper fix requires front engine teardown, replace all three timing chains, guides, tensioners, cam gears, balance shaft gears, and oil pump. 18-24 labor hours. Some shops offer preventive replacement at 80k miles before failure. If it grenades, you're looking at engine rebuild or replacement with core bearings, pistons, cylinder honing.

Estimated cost: $4,000-6,500 preventive; $8,000-15,000 post-failure rebuild

Typical onset: 80,000-140,000 mi

Symptoms: transmission fluid dripping near driver side of radiator, low fluid warning message, harsh shifting when fluid level drops, pink fluid puddles under car

Fix: The aluminum cooler lines corrode at the crimp fittings or the cooler itself develops pinhole leaks. Requires new cooler assembly and often both hard lines. Access is tight, may need bumper removal. 3-5 labor hours plus fluid flush and relearn procedure.

Estimated cost: $800-1,400

Typical onset: 70,000-110,000 mi

Symptoms: clunk on throttle tip-in and lift-off, excessive engine movement visible from engine bay, vibration at idle in Drive, shudder during aggressive acceleration

Fix: The hydraulic engine and transmission mounts deteriorate and leak fluid, allowing excessive drivetrain movement. Front mount is the usual culprit. Replace both front engine and rear transmission mount as a pair for best results. 2-3 labor hours with proper support equipment.

Estimated cost: $600-1,100

Typical onset: 90,000-130,000 mi

Symptoms: rough idle, oil consumption increases, oil residue around intake, P0171/P0174 lean codes

Fix: The check valve in the valve cover gets clogged with oil sludge causing vacuum leaks and oil blow-by. Requires valve cover removal and CCV system replacement or cleaning. Often done during balance shaft service. 2-3 labor hours standalone.

Estimated cost: $400-750

Typical onset: not mileage-driven

Symptoms: top operates slowly or hesitates mid-cycle, hydraulic fluid visible on cylinders or in trunk, top fails to latch properly, pump runs excessively

Fix: The hydraulic rams develop seal leaks over time, especially if the car sits unused. Requires cylinder rebuild or replacement and system bleed. Aftermarket rebuild kits available. 4-6 labor hours depending on which cylinder(s) fail.

Estimated cost: $800-1,800

Typical onset: 80,000-120,000 mi

Symptoms: clunking over bumps, steering wander, uneven tire wear on inside edge, vibration during braking

Fix: The front lower control arm bushings wear and cause alignment drift. Mercedes uses bonded bushings requiring full arm replacement rather than bushing service. 2-3 hours per side plus alignment.

Estimated cost: $700-1,200 both sides