Mercedes-Benz GLS X167
Weaknesses, engine ratings and buying advice
612 PS
AMG GLS 63 · Benzin
612 hp three-row — the most muted V8 in the M177 lineup
Fun to Drive!Generations
Engine Overview
The Mercedes-Benz GLS X167 is available with 7 engine variants — from 272 to 612 hp. 1 variants had engine changes — the model year is crucial.
Modern inline-six diesel with aluminium block and steel pistons. Efficient and powerful, few known weaknesses to date. Timing chain long-lived.
- !! Recall Coolant Pump — Fire Hazard (Action Code 2090008)
The vacuum-controlled coolant pump can develop leaks between the coolant and vacuum circuits. Coolant enters the EGR solenoid valves; an electrochemical reaction creates a fire hazard.
- !! Bosch CP4 Pump Sensitive to Fuel Quality from 120,000 km
The Bosch CP4 high-pressure pump is more sensitive to fuel contamination than its predecessors. Poor diesel quality can damage the pump and injectors.
Symptoms: Power loss, hesitation, injection system fault codes, in severe cases engine damage from metal swarf - !! Coolant Pump Leaking — Fire Risk (Recall) from 50,000 km
The switchable coolant pump does not reliably seal between the coolant and vacuum circuits. Coolant can overheat electrical solenoid valves — fire risk. Campaign code 2090008.
Symptoms: No direct driver symptoms — preventive recall. Possible coolant loss, electrical faults, unusual odour
+ 3 more engine weaknesses + vehicle weaknesses
Modern inline-six diesel with aluminium block and steel pistons. Efficient and powerful, few known weaknesses to date. Timing chain long-lived.
- !! Recall Coolant Pump — Fire Hazard (Action Code 2090008)
The vacuum-controlled coolant pump can develop leaks between the coolant and vacuum circuits. Coolant enters the EGR solenoid valves; an electrochemical reaction creates a fire hazard.
- !! Bosch CP4 Pump Sensitive to Fuel Quality from 120,000 km
The Bosch CP4 high-pressure pump is more sensitive to fuel contamination than its predecessors. Poor diesel quality can damage the pump and injectors.
Symptoms: Power loss, hesitation, injection system fault codes, in severe cases engine damage from metal swarf - !! Coolant Pump Leaking — Fire Risk (Recall) from 50,000 km
The switchable coolant pump does not reliably seal between the coolant and vacuum circuits. Coolant can overheat electrical solenoid valves — fire risk. Campaign code 2090008.
Symptoms: No direct driver symptoms — preventive recall. Possible coolant loss, electrical faults, unusual odour
+ 3 more engine weaknesses + vehicle weaknesses
Modern inline-six diesel with aluminium block and steel pistons. Efficient and powerful, few known weaknesses to date. Timing chain long-lived.
- !! Recall Coolant Pump — Fire Hazard (Action Code 2090008)
The vacuum-controlled coolant pump can develop leaks between the coolant and vacuum circuits. Coolant enters the EGR solenoid valves; an electrochemical reaction creates a fire hazard.
- !! Bosch CP4 Pump Sensitive to Fuel Quality from 120,000 km
The Bosch CP4 high-pressure pump is more sensitive to fuel contamination than its predecessors. Poor diesel quality can damage the pump and injectors.
Symptoms: Power loss, hesitation, injection system fault codes, in severe cases engine damage from metal swarf - !! Coolant Pump Leaking — Fire Risk (Recall) from 50,000 km
The switchable coolant pump does not reliably seal between the coolant and vacuum circuits. Coolant can overheat electrical solenoid valves — fire risk. Campaign code 2090008.
Symptoms: No direct driver symptoms — preventive recall. Possible coolant loss, electrical faults, unusual odour
+ 3 more engine weaknesses + vehicle weaknesses
The M177 is AMG's most widely used V8 biturbo today and is considered technically mature and long-lived. The hot-V turbocharger arrangement delivers spontaneous response with barely perceptible lag. Weaknesses are manageable: wastegate rattle in cold weather, ignition coil recall for early 2015 model years, valve cover gaskets with age. Regular oil changes with attention to oil quality deliver a very robust engine. In direct comparison with the M156 less emotional, but significantly more reliable and efficient.
- !! MCT Gearbox — Clutch Wears in City Traffic from 60,000 km
The MCT Speedshift gearbox (wet launch clutch instead of torque converter) wears the clutch significantly faster in frequent stop-and-go. Clutch replacement requires gearbox removal.
Symptoms: Judder on pull-away, clutch slip at full load, gearbox warning message, delayed engagement from standstill - !! Camshaft Adjuster Solenoid Draws Oil into Wiring Harness from 70,000 km
Identical issue to the M176/M278: the solenoid leaks, oil migrates by capillary action through the wiring harness. On AMG vehicles this is even more frequent due to higher oil temperatures.
Symptoms: Cold-start rattle, camshaft adjuster fault code, oil traces on connector, potential ECU consequential damage - !! Camshaft Cover Gasket Leaking — Hot-V Area from 60,000 km
The camshaft cover gaskets on the M177 AMG V8 become brittle from the high heat exposure in the hot-V. Oil escapes onto turbochargers and exhaust system.
Symptoms: Oil smell on hot engine, oil film on turbochargers, smoke from engine bay
+ 5 more engine weaknesses + vehicle weaknesses
Return to the inline-six after years of the M276 V6 — and the difference is immediately noticeable. Smoother, more even rev build-up, torque plateau from 1,600–4,000 rpm without any weakness. The 48V mild-hybrid system with integrated starter-generator (ISG) is not a marketing term: 16 kW of boost on pull-away fills turbo lag completely; measurable fuel saving in sail mode. When buying, check the 48V battery — failure costs 2,000–4,000 EUR, primarily affecting build years up to 2022. Electric coolant pumps can fail from 80,000 km. Change oil every 10,000 km, do not rely on Longlife — HPFP and camshaft adjusters are sensitive to old oil. Cold-start wastegate bushing rattle is by design and not a fault. Overall a very accomplished engine that holds 250,000 km without issues when maintained correctly.
- !! 48V ISG Battery Failure from 70,000 km
Frequently reported problem: 48V battery of the EQ Boost system fails and costs 2,000–4,000 EUR to replace. Design issue with earth connection in early vehicles.
Symptoms: EQ Boost deactivated, start-stop system failed, hybrid warning light, sporadic starting problems - !! Camshaft Adjuster Solenoid Leaking — Oil in Wiring Harness from 100,000 km
The known Mercedes problem of leaking camshaft solenoids also affects the M256 (same solenoid technology as M276/M270). Oil migrates by capillary action and destroys lambda sensors and the ECU.
Symptoms: Lambda sensor fault codes, MIL, rough running. Multiple electrical faults simultaneously as it progresses - !! Elevated Oil Consumption at Higher Mileage from 100,000 km
M256 shows elevated oil consumption from approx. 100,000 km, attributable to the PCV system and cylinder walls. Regular oil level checks necessary.
Symptoms: Dropping oil level, occasional bluish smoke after warm-up phase
+ 6 more engine weaknesses + vehicle weaknesses
4.0-litre V8 with two turbochargers in the cylinder valley — the so-called hot-inside-V arrangement keeps the exhaust paths short and virtually eliminates turbo lag. The M176 is the civilian variant of the AMG V8: same basic architecture, different mapping, not a hand-built individual unit. Water-cooled charge air coolers in the cylinder valley reduce intake charge temperature from over 140°C to near ambient. Cylinder deactivation silences four cylinders at part-load — only perceptible as minimal steering wheel vibration. Maintenance note: do not push oil change intervals, as the oil separator in the crankcase breather reacts badly to old oil and, when blocked, pushes out the valve cover gasket — extensive front-end disassembly required. Change spark plugs every 80,000 km, plan intake valve carbon cleaning after 70,000 km. When buying used, listen for wastegate rattle at part-load — addressable via Xentry. Check camshaft adjuster solenoids for oil traces at the connector.
- !! Timing Chain Stretch — M176 4.0L V8 from 120,000 km
The timing chains on the M176 V8 can stretch at high mileage. Due to the hot-inside-V design the repair is very complex as the turbochargers sit between the cylinder banks.
Symptoms: Chain rattling on cold start, camshaft fault codes, rough idle - !! Camshaft Adjuster Solenoid Draws Oil into Wiring Harness from 80,000 km
The camshaft adjuster solenoid on the M176 leaks and oil migrates by capillary action through the wiring harness to the ECU. A known Mercedes V8 issue since the M278.
Symptoms: Cold-start rattle for 1–2 seconds, camshaft adjuster fault code, oil traces on connector, in extreme cases ECU failure - !! Coolant Pump Leaking from 80,000 km
The coolant pump on the M176 can develop a leak at the seal. Coolant loss leads to engine overheating if not addressed.
Symptoms: Coolant level drops, coolant puddle under the vehicle, temperature gauge rises
+ 6 more engine weaknesses + vehicle weaknesses
The M177 is AMG's most widely used V8 biturbo today and is considered technically mature and long-lived. The hot-V turbocharger arrangement delivers spontaneous response with barely perceptible lag. Weaknesses are manageable: wastegate rattle in cold weather, ignition coil recall for early 2015 model years, valve cover gaskets with age. Regular oil changes with attention to oil quality deliver a very robust engine. In direct comparison with the M156 less emotional, but significantly more reliable and efficient.
- !! MCT Gearbox — Clutch Wears in City Traffic from 60,000 km
The MCT Speedshift gearbox (wet launch clutch instead of torque converter) wears the clutch significantly faster in frequent stop-and-go. Clutch replacement requires gearbox removal.
Symptoms: Judder on pull-away, clutch slip at full load, gearbox warning message, delayed engagement from standstill - !! Camshaft Adjuster Solenoid Draws Oil into Wiring Harness from 70,000 km
Identical issue to the M176/M278: the solenoid leaks, oil migrates by capillary action through the wiring harness. On AMG vehicles this is even more frequent due to higher oil temperatures.
Symptoms: Cold-start rattle, camshaft adjuster fault code, oil traces on connector, potential ECU consequential damage - !! Camshaft Cover Gasket Leaking — Hot-V Area from 60,000 km
The camshaft cover gaskets on the M177 AMG V8 become brittle from the high heat exposure in the hot-V. Oil escapes onto turbochargers and exhaust system.
Symptoms: Oil smell on hot engine, oil film on turbochargers, smoke from engine bay
+ 5 more engine weaknesses + vehicle weaknesses
The M177 is AMG's most widely used V8 biturbo today and is considered technically mature and long-lived. The hot-V turbocharger arrangement delivers spontaneous response with barely perceptible lag. Weaknesses are manageable: wastegate rattle in cold weather, ignition coil recall for early 2015 model years, valve cover gaskets with age. Regular oil changes with attention to oil quality deliver a very robust engine. In direct comparison with the M156 less emotional, but significantly more reliable and efficient.
- !! MCT Gearbox — Clutch Wears in City Traffic from 60,000 km
The MCT Speedshift gearbox (wet launch clutch instead of torque converter) wears the clutch significantly faster in frequent stop-and-go. Clutch replacement requires gearbox removal.
Symptoms: Judder on pull-away, clutch slip at full load, gearbox warning message, delayed engagement from standstill - !! Camshaft Adjuster Solenoid Draws Oil into Wiring Harness from 70,000 km
Identical issue to the M176/M278: the solenoid leaks, oil migrates by capillary action through the wiring harness. On AMG vehicles this is even more frequent due to higher oil temperatures.
Symptoms: Cold-start rattle, camshaft adjuster fault code, oil traces on connector, potential ECU consequential damage - !! Camshaft Cover Gasket Leaking — Hot-V Area from 60,000 km
The camshaft cover gaskets on the M177 AMG V8 become brittle from the high heat exposure in the hot-V. Oil escapes onto turbochargers and exhaust system.
Symptoms: Oil smell on hot engine, oil film on turbochargers, smoke from engine bay
+ 5 more engine weaknesses + vehicle weaknesses
Vehicle Weaknesses
| Weakness | Cost | |
|---|---|---|
| Recall: 48V earth connection fire hazard The 48V earth connection under the passenger seat was fastened with insufficient torque. High currents raise junction temperature — fire risk. 52,363 vehicles affected. Symptoms: Burning smell at passenger seat, fault in 48V electrical system, fuse blows | Low | |
| Recall: A/C condensate — fire risk Incorrectly routed A/C condensate drain hoses allow water ingress into the interior. Contact with electrics causes short circuits. 171,463 vehicles affected. Symptoms: Wet mat under dashboard, short circuits, eCall activates, engine limp mode | Low | |
| MBUX System Crash and Sluggish Response MBUX shows crashes during extended operation (black screen). Total failures occur especially after long drives over 400 km. Software updates often only provide temporary relief. Symptoms: Black screen while driving, no radio, no navigation, voice control unresponsive | Medium | |
| MBUX system freezes The MBUX infotainment no longer responds to inputs or displays frozen content. After software updates, stability sometimes worsens. Symptoms: Touchscreen frozen, navigation display outdated or black, climate control blocked | Low |
Test Reports
TÜV Report 2024
The current GLS generation shows very good main inspection results as a young range.
2023-11Top Reported Issues
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Known Problems and Issues +
A total of 38 weaknesses have been documented for the Mercedes-Benz GLS X167 (2019–2025) — 32 engine-related and 6 vehicle-related. Typical issues affect Electronics, Gearbox, Suspension.
GLS (OM656, 2019–2025) — Be Careful: Recall Coolant Pump — Fire Hazard (Action Code 2090008), Bosch CP4 Pump Sensitive to Fuel Quality, Coolant Pump Leaking — Fire Risk (Recall). Power: 286 PS.
GLS (OM656, 2019–2025) — Be Careful: Recall Coolant Pump — Fire Hazard (Action Code 2090008), Bosch CP4 Pump Sensitive to Fuel Quality, Coolant Pump Leaking — Fire Risk (Recall). Power: 330 PS.
GLS (OM656, 2019–2026) — Be Careful: Recall Coolant Pump — Fire Hazard (Action Code 2090008), Bosch CP4 Pump Sensitive to Fuel Quality, Coolant Pump Leaking — Fire Risk (Recall). Power: 340 PS.
GLS (M176, 2019–2025) — Be Careful: Timing Chain Stretch — M176 4.0L V8, Camshaft Adjuster Solenoid Draws Oil into Wiring Harness, Coolant Pump Leaking. Power: 489 PS.
GLS (M256, 2020–2025) — Be Careful: 48V ISG Battery Failure, Camshaft Adjuster Solenoid Leaking — Oil in Wiring Harness, Elevated Oil Consumption at Higher Mileage. Power: 367 PS.
GLS (M177, 2020–2025) — Be Careful: MCT Gearbox — Clutch Wears in City Traffic, Camshaft Adjuster Solenoid Draws Oil into Wiring Harness, Camshaft Cover Gasket Leaking — Hot-V Area. Power: 612 PS.
GLS (M177, 2020–2026) — Be Careful: MCT Gearbox — Clutch Wears in City Traffic, Camshaft Adjuster Solenoid Draws Oil into Wiring Harness, Camshaft Cover Gasket Leaking — Hot-V Area. Power: 489 PS.
GLS (M177, 2020–2025) — Be Careful: MCT Gearbox — Clutch Wears in City Traffic, Camshaft Adjuster Solenoid Draws Oil into Wiring Harness, Camshaft Cover Gasket Leaking — Hot-V Area. Power: 557 PS.
GLS (M177, 2023–2026) — Be Careful: MCT Gearbox — Clutch Wears in City Traffic, Camshaft Adjuster Solenoid Draws Oil into Wiring Harness, Camshaft Cover Gasket Leaking — Hot-V Area. Power: 517 PS.
What to watch out for with the Mercedes-Benz GLS? See the detailed listing of all engine and vehicle weaknesses in the sections above.
Frequently Asked Questions
What problems and weaknesses does the Mercedes-Benz GLS X167 have? +
What should I look for when buying a used Mercedes-Benz GLS X167? +
Which engine is recommended? +
Which Mercedes-Benz GLS X167 engine is the most fun? +
Is the Mercedes-Benz GLS X167 worth buying used? +
What horsepower variants are available for the Mercedes-Benz GLS X167? +
Last updated: February 2026 · All information without guarantee