2012 Mercedes-Benz E350 Problems
RepairPal has identified the most common problems with the 2012 Mercedes-Benz E350 based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
The camshaft adjuster solenoid (which is related to the variable valve timing system) may fail or timing chain/balance shaft components may wear, resulting in illumination of the Check Engine Light and various drivability issues. Mercedes-Benz has released a service bulletin outlining specific repair instructions depending on fault codes stored.
Vehicles equipped with a 7-speed automatic transmission may develop a rough shifting condition, most commonly going up from first to second gear and going down from third to second or second to first gear. Our technicians tell us this is due to an internal component failure. Mercedes has released updated parts; the transmission will need to be removed and disassembled to complete the necessary repairs.
Lack of audio or cell phone functionality may be related to the failure of the audio gateway module.
The Mercedes Benz E350 may have engine oil seeping or leaking from the back of the cylinder heads. This is commonly misdiagnosed as leaking valve covers.
On the back of the cylinder heads there are three, in total, plastic expansion plugs that plug access ports to the camshafts. These plugs are well known for seeping oil, and leaking if left unattended. The oil will run down the back of the engine and eventually make it to the ground.
Replacement of these three plastic plugs is extremely simple, and should be done as regular maintenance. The recommended interval for replacement is every 60,000 miles.
The power steering reservoir designed for the Mercedes Benz E350 commonly leaks power steering fluid causing a screeching sound when turning the steering wheel, especially when the vehicle is stopped. The power steering light may illuminate on the dash for more severe leaks.
This is caused by cracking in the plastic reservoir, or a hardened, brittle seal between the power steering reservoir and power steering pump.
Remediation involves replacing the power steering fluid reservoir, power steering fluid, bleeding the system of air, and replacement of the seal between the reservoir and power steering pump.
Due to the size and material used on the brakes of these vehicles, the brakes may start to squeak around the 50 percent wear point. The brake rotor surfaces become uneven, causing a lip to form at the outer edge of the rotor. Because of this, the rotors are usually replaced when the pads are worn (pad life varies depending on driving style and terrain).
A vibration felt through the center floor of the vehicle can be caused by driveshaft flex discs, which crack and shred, causing excessive driveshaft movement. Not repairing these can cause damage to the driveshaft center support bearing, or, in the worst case scenario, damage to the transmission or differential.