I did some research on Mercedes 3.0l diesel motors and there seems to be an issue with the seal failing about 50,000 miles causing the motor to leak oil and the seal as well as the oil cooler need to be replaced. It is such a common problem on the 3.0l diesel engines that when you call any repair shop the first thing they ask is if the car is a diesel. Also the seal replacement is all over the…
2012 Mercedes-Benz S-Class powertrain problems
severe 3 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Complaints
3
Recalls
0
Avg fix
$2,500
1crash
When does it fail?
Of the 3 powertrain complaints filed for the 2012 Mercedes-Benz S-Class, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 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
No new NHTSA powertrain complaint has been filed on this vehicle in over 9 years — the issue may be aging out of the active population.
What owners are reporting 3 most recent
2012 Mercedes s550. Consumer states vehicle slid backwards in parking lot *tgw the consumer stated the safety issue was regarding the vehicle being put in the neutral position after turning off the engine. The consumer stated three weeks ago, he had the misfortune of parking his vehicle in a parking lot. Without opening the door, he turned off the engine and when he removed his foot from the…
While driving at freeway speeds car went into limp mode. Engine rmp were limited to 1500rpm and speed dropped to 25mph.this happened 3 times during week of 3/14/16 and again on 3/22/16. Had to make defensive emergency maneuver to steer the car away from the traffic lanes and stop on the side of the freeway. Was almost rear ended by a semi. Car had to be turned off and restarted to come back to…
Had powertrain trouble with your 2012 Mercedes-Benz S-Class?
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 powertrain problem on the 2012 Mercedes-Benz S-Class?
It's a meaningful issue. 3 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $2,500.
At what mileage does the powertrain typically fail?
Based on the 3 complaints filed, powertrain issues most often appear around 53,250 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain 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 powertrain?
No active recalls currently cover powertrain 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/2012/Mercedes-Benz/S-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.