2008 MERCEDES-BENZ SL

Typical onset: 60,000-120,000 mi

Symptoms: Metal shavings in oil, Check engine light with cam/crank correlation codes, Rough idle or misfire, Catastrophic engine noise if gears strip

Fix: Balance shaft gears wear prematurely, dumping metal through the engine. Requires complete teardown, new balance shaft assembly, chain, guides, and often damaged bearing surfaces. Many shops recommend used/reman long block instead. 25-35 hours labor for in-chassis rebuild, 18-24 for engine swap.

Estimated cost: $8,000-15,000

Typical onset: 70,000-130,000 mi

Symptoms: ABC warning light, Vehicle sagging at one corner overnight, Rough ride or bouncing, Hydraulic fluid leaks under car

Fix: Hydraulic struts, accumulators, and pulsation damper all age out. Struts alone run 3-4 hours each corner. Pulsation damper is 2 hours. System must be bled with Star Diagnostics. Many owners convert to coilovers ($3-4k) to escape ongoing ABC costs.

Estimated cost: $2,500-5,000

Typical onset: 80,000-140,000 mi

Symptoms: Roof operation stops mid-cycle, Loud grinding or whining from trunk, Roof will not latch or unlatch, SDS control module errors

Fix: Hydraulic pump motors fail, trunk latches seize, and micro-switches go bad. Pump replacement is 3-4 hours, requires roof calibration. Latch mechanisms need individual diagnosis. Many failures occur from infrequent use—roof should be cycled monthly.

Estimated cost: $1,800-3,500

Typical onset: 90,000-150,000 mi

Symptoms: Harsh or delayed shifts, Limp mode activation, Transmission fault codes, Slipping between gears

Fix: Conductor plate (wiring harness inside trans) and valve body solenoids fail. Requires pan drop, fluid change, and 6-8 hours labor for conductor plate replacement. Full valve body is 10-12 hours. Use OE Mercedes fluid only.

Estimated cost: $1,500-3,200

Typical onset: 100,000-160,000 mi

Symptoms: Suspension warning light, Compressor runs constantly, Vehicle sits low after sitting overnight, Compressor overheating

Fix: If equipped with Airmatic instead of ABC, air struts leak at bellows and compressor fails from overwork. Struts are 2-3 hours each, compressor is 2 hours. Relay (N51) also fails causing compressor not to run. Less catastrophic than ABC but still expensive.

Estimated cost: $1,200-2,800

Symptoms: Long crank before start, Stalling or hesitation under load, Fuel smell from tank area, Limp mode or reduced power

Fix: In-tank fuel pump assemblies fail, external filter clogs (often neglected on 30k service), and pressure dampers leak. Pump is 3-4 hours, requires tank drop. Filter is 0.8 hours but often skipped. Fuel system should be serviced every 30k religiously on these V8s.

Estimated cost: $800-1,800

Typical onset: 70,000-110,000 mi

Symptoms: Clunk on acceleration or deceleration, Excessive vibration at idle in Drive, Visible sagging or torn rubber on inspection

Fix: Hydraulic engine and transmission mounts collapse with age. Both should be done together—4-5 hours total labor. Ignore this and you accelerate wear on driveline components. Straightforward job but parts are expensive.

Estimated cost: $1,200-1,800