Vehicle cranks but will not start, dealer first replaced fuel pump ($1500),then when came to pickup vehicle would not start at dealer, replaced starter(no charge), drove for 2 weeks issue came back, took to dealer , they kept it for 20 days and said some sort of control module, but who knows. Its been 15 months and car just stopped smack in middle of freeway at 60 miles per hour and would not…
2006 Mercedes-Benz R-Class engine problems
moderate 28 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Failure mileage
Complaints
28
Recalls
0
Avg fix
$3,100
When does it fail?
Of the 28 engine complaints filed for the 2006 Mercedes-Benz R-Class, here's the actual mileage breakdown — failures cluster heaviest at 75,000-100,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Owners have filed 28 engine complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Engine accounts for 22% of all owner complaints filed against this vehicle, across 8 categories tracked.
The failure pattern owners describe
Owners of 2006 R350s consistently report premature balance shaft gear wear that Mercedes knew about well before most vehicles hit the road. The problem manifests as a check engine light (codes P0016, P0017), followed by rough idle, engine vibration, stalling at stops or highway speeds, and loud knocking. Mechanics find metal particles in the oil and worn or missing gear teeth. The root cause, owners state, is defective hardening of the gears during manufacture—a flaw that affects the M272 and M273 engines across multiple Mercedes model lines.
Mercedes issued a technical service bulletin in 2007 but refused full recall, leaving owners on the hook for $4,000–$7,500 repairs that require engine removal and replacement of the balance shaft, gear, timing chain, oil pump, tensioners, and guides. Dealers initially downplayed the issue or dismissed it as a gas cap problem, then claimed it was wear-and-tear, not a defect. After class-action suits were filed, Mercedes began covering some repairs on an ad-hoc basis. Many owners were told to trade or sell their vehicles—essentially dumping defective cars back onto the used market. Owners report dealerships acknowledging this as "a common problem" affecting nearly all 2006 and 2007 R350s, yet Mercedes has not issued a recall or mandatory service campaign.
Failure modes owners describe
Balance Shaft Gear Wear or Failure
Defective balance shaft gears wear prematurely and excessively due to insufficient hardening during manufacture. Metal particles accumulate in oil, gears lose teeth, and the shaft can fail suddenly, causing loss of engine power and timing issues. Owners report this as a known manufacturing defect affecting M272 and M273 engines across multiple model years.
When: Typically 40,000–88,000 miles; one complaint at 48,500 miles, others between 62,000–88,000 miles.
Symptoms owners cite: Check engine light illuminates; Engine misfires or loses power; Rough idling or high idle at stops; Strong engine vibration or knocking; Engine stalling while driving or at traffic lights; Loud rattling or vibrating noises from engine; Metal particles visible in oil pan
Codes mentioned: P0016, P0017, P0300 (inferred from misfire complaints), 1200, 1208
Repairs/costs cited: Repair requires removing the engine and replacing balance shaft, gear, timing chain, oil pump, tensioners, and guides. Owners cite repair costs between $4,000 and $7,500; one dealer quoted $9,000. One owner replaced solenoids for camshaft balancers prior to learning the root cause was the balance shaft gear itself.
Recalls/TSBs owners mention: Mercedes issued Technical Service Bulletin (TSB) S-B-03.30/08J in 2007 but did not issue a full recall. MB initially denied the defect exists, later provided goodwill repairs on a case-by-case basis after class-action litigation was filed. Some owners with expired warranties were covered; others were not. Dealers advised owners to trade or sell affected vehicles.
Intake Manifold Failure
Intake manifold develops cracks or fails, requiring replacement. Commonly appears alongside balance shaft wear and is often discovered during diagnosis for check engine light issues.
When: Mileage not consistently stated in narratives; occurs concurrent with balance shaft wear.
Symptoms owners cite: Check engine light illuminates; Rough idling; Shaking at idle
Repairs/costs cited: Intake manifold replacement is often bundled with balance shaft repair, adding to total repair cost (examples cite $6,500–$7,000 for both repairs).
Timing Chain Wear or Damage
Early wear on timing chain accompanies balance shaft gear failure. If balance shaft failure is not addressed, the timing chain can jump, smash valves, and cause catastrophic engine damage or sudden loss of power.
When: Discovered at 40,000–66,000 miles during diagnosis of balance shaft wear.
Symptoms owners cite: Check engine light; Engine vibration; Loss of power; Potential engine seizure if left unrepaired
Repairs/costs cited: Timing chain replacement is part of the complete balance shaft repair package ($4,000–$7,500).
Synthesized from 28 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 1 most recent
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File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2006 Mercedes-Benz R-Class?
It's a documented issue but not catastrophic. 28 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Across the 23 complaints that reported odometer mileage, most engine failures cluster between 55,000 and 92,261 miles, with the median around 79,000. A quarter of owners report trouble before 55,000; a quarter make it past 92,261. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2006/Mercedes-Benz/R-Class.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.