Airmatic strut and compressor failure
Attaches to W164 at chassis level · Suspension · carried by 2 variants across 1 chassis
Overview
Airmatic strut and compressor failure is a common fault recorded against W164 at chassis level, typically from 90–180k km. It shows up as the car sitting low after standing, a message on the dashboard, or a compressor that runs far longer than it should. Where it's documented, the repair runs €600–€3,000 (one strut at the cheap end, multiple struts and a compressor at the dear end, costs dated 2026-07), and it can be checked before you buy. 2 variants across 1 chassis in this database inherit it.
What happens
Symptom. The car sitting low after standing, a message on the dashboard, or a compressor that runs far longer than it should.
Cause. The struts perish and leak, and the compressor then runs continuously until it burns out. Cars used for short trips and left standing suffer first, because the bags crack where they fold.
How to check it
Static checks
View the car cold and before it's been started, then cycle every ride height and watch all four corners respond. A compressor that runs on after levelling is the early warning.
Engine off, ideally on a lift.
Every variant that carries this
| Variant | Chassis | Body | Years | Risk | Good buy | Cost as % of good buy |
|---|---|---|---|---|---|---|
| ML 320 CDI OM642 | W164 | SUV | 2005–2011 | R4 | €7,250 | 25% |
| ML 350 M272 | W164 | SUV | 2005–2011 | R4 | €6,600 | 27% |
The last column is the point. The same repair is an inconvenience on one variant and a reason to scrap the car on another. A failure costing a quarter of the vehicle's value changes the purchase decision regardless of how rare it is.