Models · Mercedes-Benz
Mercedes-Benz GL-Class X164 buying guide
The first GL-Class, a seven-seat luxury 4x4 sold from 2006 to 2012, with V6 and V8 diesels and V8 petrols. Most UK cars are the 3.0 V6 diesel, and Mercedes reliability on this era of car is generally good.
The versions
- GL320 CDI 3.0 V6 diesel (224bhp), later the GL350 BlueTEC (around 261hp) with AdBlue
- GL420 CDI V8 diesel, 306bhp, the choice for serious towing
- GL450 4.6 V8 petrol (340bhp) and GL500 V8 petrol (388bhp)
- Seven-speed automatic and four-wheel drive on every car
- Airmatic air suspension as standard
What to check on a X164 GL
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
Airmatic air suspension
What to look for: When you arrive, check the car sits level on all four corners and hasn't sunk overnight. With the engine running, listen for the compressor running for long periods, and watch for suspension warnings on the dashboard.
Why it matters: Airmatic is standard on the GL and is the system most often in need of attention. A leaking strut makes the compressor work harder to keep the car level, which wears it out. Recent suspension work on the invoices is a plus.
Knocking or ticking from the diesel engine
What to look for: Start the engine, ideally from cold, and listen at the open bonnet for knocking or a metallic ticking. Look around the injectors on top of the engine for black, tarry deposits.
Why it matters: A leaking injector seal is a very common issue on the 3.0 V6 diesel and can sound like a knock. Crankshaft main bearing wear is a rarer cause, usually heard as a metallic ticking. Ask for the injector seal history and get any knock diagnosed before buying.
Oil leaks around the turbo and steering
What to look for: With the bonnet up and a torch, look around the turbocharger in the middle of the engine for wet oil, and around the power steering pump and pipes for fluid. Look underneath for fresh drips.
Why it matters: Oil leaks around the turbo are not unknown on these engines, and the power steering can leak fluid too. Both are fixable, and a dry engine bay is a sign of a car that's been looked after.
Also in the full guide
- Tail lights, locks and the tailgate
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the X164 GL
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.