My 2008 ML350 sits low in the back every morning. Is it the compressor?

Usually not at first. A truck that sinks overnight and levels after start has a leak, most often a cracked rear air spring, and the compressor is still doing its job. If it has been doing that for months, the compressor is probably worn as well. We leak-test all four corners and measure compressor output before quoting so you replace what has failed, not both by default.

How do I know if my ML has the affected M272 balance shaft?

The affected engines are mostly 2006–2008 builds, and the serial number on the block tells us whether it falls within the range Mercedes published. We check that number first, then compare cam deviation values in XENTRY. A 2010 or 2011 ML350 with a P0016 code has the updated shaft and nearly always needs a smaller repair such as an adjuster or chain.

Does the 2016–2019 GLE have the same transmission problem as the older ML?

No. Those GLEs use the 9G-Tronic, which does not have the 722.9 conductor plate failure. What it does have is sensitivity to adaptation values; a rough shift after a battery swap or a module update frequently clears with an adaptation reset and a drive cycle. We check the fluid level and condition at the same visit, since the 9G fluid still ages in this heat.

My 2021 GLE 450 showed a red battery warning and stalled. Is it safe to drive?

Treat it as a tow, not a drive. That warning on the M256 means the 48-volt network dropped and the car may not restart once shut off. The cause is commonly the starter-generator, the DC/DC converter or the 48-volt coolant pump, and the fix includes VIN coding and a software check. We hold the online XENTRY access to do that in-house.

Can you service a GLE under the dealer prepaid maintenance plan?

A prepaid plan bought from a dealer is honored only by dealers, so those visits belong there until it runs out. Once it ends, Service A and B here use the same MB 229.5 or 229.52 oil, the same filter spec and the same XENTRY counter reset, at the ranges on this page, with the repair work covered for 2 years parts and 2 years labor, up to 24,000 miles, nationwide.

W164 ML · W166 ML / GLE · V167 / C167 GLE

Mercedes-Benz GLE and ML Repair in Dallas

Three generations of the mid-size Mercedes SUV come through the shop: the W164 ML with its M272 and leaking air springs, the W166 with the M276 and the 722.9, and the V167 GLE with the M256 inline-six and its 48-volt system. Each has a different failure list, and the diagnosis starts from the chassis code, not the badge.

Get an estimate All models

Repairs covered by a 2-year/24,000-mile warranty, independent shop

Generations

Which GLE and ML generations are these?

W164 ML
2006–2011
M272 V6 and M273 V8, 722.9 7G-Tronic, optional Airmatic; the 2006–2008 balance shaft and the air springs define its repair history.
W166 ML / GLE
2012–2019
M276 V6 and M278 V8 direct injection, 722.9 until the 9G-Tronic arrived in 2016; renamed GLE for the 2016 model year.
V167 / C167 GLE
2020–
M256 inline-six with 48-volt starter-generator, M264 four-cylinder, 9G-Tronic, Airmatic with optional E-Active Body Control; C167 is the coupe.

Known failures

What goes wrong on the GLE and ML, by generation?

Problem
W164, 2006–2011: Vehicle drops overnight on one or both rear corners, "Airmatic Visit Workshop" after the compressor runs too long
Likely cause
Rear air springs crack at the fold line; the compressor overheats keeping up and its piston seal wears, then the relay sticks
The fix
Pressure-test each corner with the Airmatic tool, replace the leaking spring or strut, test the compressor delivery rate and replace it with the relay if it is below spec, then calibrate ride height
Airmatic Air Suspension Repair
Problem
W164 with M272, 2006–2008: Check engine light with camshaft position correlation codes on bank 1, rough idle, no visible leak
Likely cause
Soft balance shaft sprocket teeth wear on early M272 engines and let the intake cam timing drift
The fix
Confirm with XENTRY cam deviation values and a serial-number check, then replace the balance shaft, chains, guides and tensioner in one job
M272/M273 Balance Shaft and Timing Chain Repair
Problem
W164 and early W166, 2006–2015: Transmission limp home in third gear, no reverse after a hot restart, speed sensor codes
Likely cause
The 722.9 conductor plate loses its Y3/8n1 or Y3/8n2 speed sensor as the solder and sensor age
The fix
Read the stored sensor fault, replace the conductor plate with coding to the VIN, service the fluid and filter, and run the adaptation
722.9 7G-Tronic Transmission Service and Repair
Problem
W166, 2012–2019: Rattle for a second on cold start, P0016 or P0017 codes, slow adjuster response in the actual values
Likely cause
M276 camshaft adjusters and their central valves wear, and the timing chain stretches on higher-mileage engines
The fix
Measure cam deviation and chain elongation in XENTRY, replace the adjusters, central valves and chain set as the readings dictate
M272/M273 Balance Shaft and Timing Chain Repair
Problem
W166, 2012–2019: Oil smell after a drive, drips near the bellhousing, oil on the exhaust shields
Likely cause
M276 valve cover gaskets, the oil cooler seals under the intake and the rear main seal harden in Texas heat
The fix
UV dye and a pressure check to pin the source before any part comes off, then reseal the component that is actually leaking
M272/M273 Oil Leak Repair
Problem
V167, 2020–: Red battery warning, engine stall at a stop, "Stop vehicle, leave engine running" message
Likely cause
The M256 48-volt belt-less starter-generator, its DC/DC converter or the 48-volt electric coolant pump drop out and the 12-volt side cannot carry the load
The fix
XENTRY quick test of the 48-volt network, log the fault freeze frames, replace the failed component with VIN coding and apply the current software
XENTRY Diagnostics
Problem
V167, 2020–: Suspension warning after a wash or a cold night, uneven ride height with E-Active fitted
Likely cause
Level sensors, strut air lines and the Airmatic compressor on the V167 are sensitive to moisture and to a dropped 48-volt supply on E-Active cars
The fix
Guided Airmatic test, repair the leak or sensor, then full level calibration
Airmatic Air Suspension Repair

What are the service intervals for the GLE and ML?

Service A: 10,000 miles or 1 year, MB 229.5 or 229.52 oil by engine, filter, inspection, counter reset in XENTRY
Service B: 20,000 miles or 2 years, adds brake fluid exchange and the cabin combination filter
Transmission fluid: 722.9 and 9G-Tronic fluid and filter on the mileage the maintenance booklet lists for that unit; sooner for ML owners who tow
Airmatic: Compressor delivery and corner leak-down checked at every B service on W164, W166 and V167 cars with air suspension
48-volt battery: V167 M256 cars: state of health read in XENTRY at every service and after any 48-volt fault

Why do W164 ML air springs fail before anything else?

The W164 was the first ML offered with Airmatic across the range, and the rear air springs are the component that sets its reputation. The rubber bellows roll over a piston every time the suspension moves, and after a decade of Dallas summers the fold line cracks. The first sign is a truck that sits low in the morning and levels once the engine runs; the compressor is masking the leak.

That masking is what kills the compressor. The unit was never designed to run for minutes at a time, and once the piston ring and cylinder wear it cannot reach the pressure the system asks for. The relay on the fender then sticks closed, which is why a complete W164 repair often includes the spring, the compressor and the relay rather than just the part that triggered the warning.

The front struts last longer but not forever. When one fails it is usually the strut bellows or the residual pressure valve at the top, and because the damper and the spring are one assembly the whole strut is replaced. We test every corner with the Airmatic tool before quoting, because replacing one spring on a truck with a second slow leak only moves the problem.

Is the M272 balance shaft a risk on a 2006–2008 ML350?

Yes, on the engines built before the hardened sprocket was introduced. The ML350 shipped with the M272 V6 from 2006, and the engines affected by the balance shaft sprocket wear were built roughly through 2008, with serial numbers up to the ranges Mercedes published in the class-action coverage. On the ML500 and ML550 the M273 V8 has the equivalent idler gear issue.

The symptom is a camshaft correlation code, P0016 on most of the trucks we see, without a mechanical noise and often without a drivability complaint. XENTRY shows the intake cam deviation on bank 1 drifting past specification. We check the engine serial against the affected range first; a truck outside it with the same code usually needs a cam adjuster solenoid or a stretched chain instead, which is a much smaller repair.

The repair itself means the front of the engine comes apart: timing cover, both chains, guides, tensioner and the shaft. On the W164 the engine stays in the truck but the radiator support and the front accessories come off. It is a two-to-four-day job and the single most expensive repair on this generation, so we confirm it with measured data, not with the code alone.

What goes wrong with the W166 GLE and ML?

The W166 replaced the W164 in 2012 and brought the M276 direct-injection V6 and the M278 twin-turbo V8. The common complaints are oil leaks and timing-related codes. The M276 valve cover gaskets harden early in this climate, the oil cooler seals under the intake weep onto the bellhousing, and on higher-mileage trucks the camshaft adjusters or the chain itself stretch far enough to set P0016 and P0017 codes on cold starts.

Transmissions split by year. Through 2015 the W166 used the 722.9 7G-Tronic, with the same conductor plate speed-sensor failure the W164 had, usually arriving as a hot-restart limp mode. From 2016, when the truck became the GLE, the 9G-Tronic 725.0 took over. It is a more robust unit but it is adaptation-sensitive; a harsh 2-3 shift or a flare after a battery replacement often clears with an adaptation reset rather than parts.

Air suspension carried over as an option and the rear springs still sag with age, though later than on the W164. The W166 also had Active Curve System on some trims, a hydraulic anti-roll setup; its lines corrode at the fittings and a leak there needs a specialist bleed procedure, which we perform with XENTRY rather than by guesswork.

What are the V167 GLE 48-volt and M256 problems?

The 2020-on V167 GLE 450 and GLE 53 use the M256 inline-six with an integrated starter-generator, an electric auxiliary compressor and a 48-volt electrical network. When the 48-volt side falters the symptoms look alarming: a red battery warning, a stall at a stoplight with no restart, or the message telling the driver not to shut the engine off. The usual culprits are the starter-generator itself, the DC/DC converter or the 48-volt coolant pump.

These faults are diagnosed from the freeze frames, not from the symptom. A dropped 48-volt supply also knocks out E-Active Body Control on trucks that have it, so a suspension warning can arrive with the battery warning and send an owner chasing the wrong system. We run the XENTRY quick test, read the 48-volt battery state of health, and then follow the guided test for the component that actually logged the first fault.

Software matters more on the V167 than on earlier trucks. Several of the stall and warning complaints are addressed by control unit updates that a shop without online SCN coding cannot apply. We hold the OEM subscription for exactly this reason, and a V167 visit normally ends with a check for open software measures on the VIN.

How does Dallas driving affect a GLE or ML?

Heat is the main factor. Air springs, valve cover gaskets and the 722.9 fluid all age faster at sustained underhood temperatures, and a truck that spends August idling on Central Expressway runs its Airmatic compressor and its cooling fans harder than the factory interval assumes. We treat 20,000-mile transmission fluid inspections and annual Airmatic leak-down checks as normal on these trucks.

Towing is the second factor. The ML and GLE are rated for a serious trailer and plenty of owners use them for a boat on Lake Ray Hubbard or a horse trailer out US-80. Towing in this heat shortens the transmission fluid life and loads the rear air springs; if you tow, say so when you book and we adjust the inspection accordingly.

Every repair on a GLE or ML here is covered for 2 years parts and 2 years labor, up to 24,000 miles, nationwide. For a written estimate with the ranges on this page, email service@mercedesbenzrepair.net with the year and whether the truck has air suspension.

Costs

What do GLE and ML repairs cost in Dallas?

What do GLE and ML repairs cost in Dallas?
Service	Price range	Typical time
Airmatic strut (per corner)	$1,100–$2,200	2–3 hours
Airmatic compressor	$700–$1,300	2–3 hours
M272 balance shaft (2006–2008 ML350)	$4,200–$6,500	2–4 days
722.9 conductor plate with coding	$1,300–$2,200	3–5 hours
722.9 or 9G-Tronic fluid and filter	$350–$550	2 hours
M276 valve cover gaskets (pair)	$550–$950	3–5 hours
Service B	$349–$649	2–3 hours

Ranges are typical independent-shop pricing in Dallas for the W164, W166 and V167. Engine (V6 or V8), Airmatic versus steel springs and whether E-Active Body Control is fitted move the final figure; the written estimate states it before work starts.

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