Models · Mercedes-Benz
Mercedes-Benz M-Class W164 buying guide
The second M-Class, sold from 2005 to 2011 and a big step up in quality from the first. Most UK cars are V6 diesels, and reliability tends to be good on cars that have been serviced properly.
The versions
- Diesel: ML280 CDI and ML320 CDI 3.0 V6; ML420 CDI V8 (306hp), renamed ML450 CDI from May 2009
- Petrol: ML350 V6 (272hp) and ML500 V8, both rare in the UK
- Seven-speed automatic on every car, with no manual
- Steel springs or optional air suspension
- The ML63 AMG is covered separately
What to check on a W164 ML
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
Oil cooler seal leaks on the V6 diesel
What to look for: On an ML280 CDI or ML320 CDI, look around the top and back of the engine with a torch for wet oil or oily grime. From underneath, look at where the engine meets the gearbox for oil pooling or dripping.
Why it matters: The ML280 CDI and ML320 CDI share their 3.0 V6 diesel with the CLS and E-Class of the time, and a leaking oil cooler seal is a known fault on that engine, with a revised seal used later. Oil spreads down towards the gearbox over time. New seals fix it, and invoices showing it done are a plus.
The electric tailgate
What to look for: Open and close the powered tailgate fully several times. It should move smoothly and steadily, without straining, stalling or reversing. Check it sits flush with the body when closed.
Why it matters: If the tailgate isn't aligned properly, the extra strain can burn out its motors. A September 2009 recall also covered the automatic tailgate opening, so check that work has been done.
Gearbox shifts and transmission servicing
What to look for: On the drive, let the seven-speed automatic change up and down through the gears. Note any harsh, rough or delayed changes, or a gearbox that holds one gear. Look in the history for transmission oil and filter changes.
Why it matters: Every W164 uses the seven-speed automatic, and its oil and filters are due at 37,000 miles. Smooth shifts and a record of that service are a sign of a car that's been looked after.
Also in the full guide
- Engine cut-out and fuel leak recalls
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the W164 ML
The CrankSight guide walks you round the car on your phone at the viewing, with every check for the exact version you're looking at: what to look for, where to find it, and what anything you find is likely to cost. As you go it builds an assessment of that car, and if you view more than one, it lines them up side by side.
£29 for the model, used on as many cars as you like, delivered within 72 hours or your money back.
Other generations
General points for the model, last checked October 2026. Every car is different, so treat this as a guide to what to look at, not a verdict on any car. CrankSight is independent and has no connection with Mercedes-Benz.