2003 Mercedes-Benz C320 Engine cooling Problems
- Complaints
- 3about this part
- Share
- 14%of 22 total for the year
- Median mileage
- 50,026miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 3 complaints about the engine cooling of the 2003 Mercedes-Benz C320, 14% of the 22 complaints for this model year. Where a mileage was given, the median is 50,026 miles.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“This happened in my 2003 C320 at 54,000 miles. I initially noticed a light rubbing or grinding while accelerating, with light vibration. At the dealership I was told I would need a new torque converter, new radiator, and a fluid flush. The radiator fluid was mixing with the transmission fluid. After those repairs, my C320 was still shifting hard and the grinding noise was still there. It turns out the transmission was ruined as well. Two replacement transmissions were needed until it was ready to be picked up. …”
NHTSA complaint #10197622, filed 2007-07, 54,352 miles“I have a 2003 c 320 mbnz, the radiator leaks into the transmission. The radiator needs to be replaced. This leaking radiator fluid damaged the transmission, and it has to be replaced. This problem caused a lack of power and therefore a loss of acceleration. It happened without any warning, leaving you vulnerable due to the loss of power, a very dangerous situation which may cause an accident. The car has only 50026 miles on it.”
NHTSA complaint #10508867, filed 2013-04, 50,026 miles“On a 2003 c 320 mbnz, the radiator now leaks into the transmission. This is going to require the radiator to be replaced and for the transmission to be flushed. This leaking radiator fluid could have already damaged the transmission, and if so, it will have to be replaced. This problem causes a lack of power and therefore a loss of acceleration. It happens without any warning, often leaving you vulnerable due to the loss of power, a potential accident waiting to happen.”
NHTSA complaint #10285432, filed 2009-09, 47,115 milesRelated service bulletins
- 10135867Jun 9, 2015Engine noises after engine start
- 10167489Mar 19, 2014Noise: A rattling noise may be heard from the area of the chain drive for approx. 2-5 seconds after engine start. And/or: Fault code entries in engine control unit: SIM271DE20…
- 10167508Mar 3, 2014Soot particles collecting on the bumper. Most visible in the area around the tail pipes, especially on light-colored finishes
Engine cooling: other model years
Other parts of the 2003 Mercedes-Benz C320
7 complaintsTransmission and drivetrain
5 complaintsAir bags
4 complaintsFuel system
3 complaintsVisibility (wipers, defrost, mirrors)
3 complaintsExterior lighting
2 complaintsSuspension
2 complaintsVehicle speed control
2 complaintsBrakes
1 complaintsEngine
1 complaintsEquipment
1 complaintsLatches, locks and linkages
1 complaints
← All problems reported for the 2003 Mercedes-Benz C320
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology