2022 MERCEDES-BENZ GLS580 X167

Typical onset: 15,000-60,000 mi

Symptoms: Check engine light with cam/crank correlation codes (P0016, P0017, P0018, P0019), Rough idle and significant power loss, Metallic ticking or knocking from valve train area, Metal shavings in oil filter during service, Eventual total loss of power requiring tow

Fix: Mercedes issued extended warranty coverage (TSB LI51.30-P-078260) but many cases still require complete engine replacement or rebuild with updated camshafts. Involves removing engine, full teardown, inspecting all bearings and cylinder walls for damage from metal contamination, replacing camshafts, lifters, timing components, and often pistons/rings if cylinder scoring occurred. 40-60 hours labor minimum for complete rebuild, 25-35 hours for engine replacement with reman unit.

Estimated cost: $25,000-45,000

Typical onset: 40,000-80,000 mi

Symptoms: Transmission slipping or harsh shifts, Oil in coolant or coolant in transmission fluid (strawberry milkshake fluid), Transmission overheating warnings on dash, Coolant loss with no external leaks visible

Fix: The internal transmission oil cooler in the radiator can fail, allowing cross-contamination. Requires radiator replacement, complete transmission fluid flush (often multiple flushes), new filter, and valve body replacement if contamination reached TCU. If caught early, 8-10 hours; if delayed and valve body damaged, add 12-15 hours for transmission removal and internal work.

Estimated cost: $3,500-8,500

Typical onset: 30,000-70,000 mi

Symptoms: Clunking noise during gear changes, especially reverse to drive, Excessive vibration at idle in drive, Visible drivetrain movement when applying throttle from stop, Harsh engagement when shifting

Fix: The GLS580 is heavy and the 9-speed transmission puts stress on mounts. Front transmission mount typically fails first. Requires lifting vehicle, supporting transmission, removing old mount and installing updated part. 2-3 hours labor. Often worth doing both transmission mounts simultaneously.

Estimated cost: $800-1,400

Symptoms: Intermittent rough running or hesitation under load, Long cranking time before starting, Reduced power at highway speeds, Fuel system pressure codes (P0087, P0088)

Fix: M176 engines are sensitive to fuel quality. Contaminated fuel or failing in-tank pump can clog the main fuel filter mounted under vehicle near tank. Filter is not a regular maintenance item per Mercedes but should be inspected if fuel delivery issues arise. Requires dropping exhaust heat shields and may need fuel system depressurization. 2-3 hours labor. If high-pressure pump also affected, add 4-5 hours.

Estimated cost: $600-2,200

Typical onset: 50,000-90,000 mi

Symptoms: Rattling noise on cold start that disappears after warmup, Underboost or overboost codes (P0299, P0234), Reduced power with check engine light, Wastegate actuator position fault codes

Fix: Twin turbos with electronic wastegate actuators can develop play in linkage or actuator motor failure. Diagnosis requires scan tool to monitor wastegate position. If actuator only, 3-4 hours per side; if turbo replacement needed due to shaft play, 8-12 hours per turbo due to tight engine bay. Often both turbos show wear at similar mileage.

Estimated cost: $2,500-9,000

Typical onset: 60,000-100,000 mi

Symptoms: Vehicle sitting lower than normal, especially after sitting overnight, Compressor running excessively or constantly, Suspension malfunction warning with limited ride height adjustment, Hissing noise from compressor area in rear cargo

Fix: Air suspension system works hard on the heavy GLS. Compressor or valve block (which controls individual corner valves) typically fails first. Compressor replacement is 3-4 hours; valve block is 4-6 hours due to location and need to calibrate system. Often worth replacing both together if compressor has over 80k miles.

Estimated cost: $2,800-5,500