2009 Mercedes-Benz C350 Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 2009 Mercedes-Benz C350
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2009 Mercedes-Benz C350 ProblemsOil Seepage on Back of the Cylinder Heads
The Mercedes Benz C350 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 C350 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.
When starting the engine after sitting for several hours, a knocking sound may be heard for several seconds. This is a common issue with the 2005-2010 Mercedes Benz C350. There are three common problems that can cause this sound to occur:
-Oil pressure building too slowly, allowing for movement between the crankshaft and crankshaft bearings
The remediation for these problems can be crankshaft bearing replacement with correct size, replacement of timing components, or balance shaft replacement.
2009 Mercedes-Benz C350 Questionsengine will not turn over. new battery. (1 answer)
nothing happens when key is turned
I did not use the car for 5 days. Just had my A service done 10 days ago. Today, it wont start. All internal and external lights go on, including radio when key is in ignition, but no sound from engine, only light click sound. This never happened before.
It still has the original battery (5.5 ye...
2009 Mercedes-Benz C350 RecallsPassenger Frontal Air Bag Inflator Ruptures On Deployment
The passenger frontal air bag inflator may rupture on deployment, causing metal fragments to come through the air bag and injure occupants. Dealers will replace the passenger frontal air bag module free of charge to resolve the concern.
The driver's frontal air bag inflator may deploy the air bag with excessive pressure, resulting in the inflator rupturing and causing metal debris to be sprayed onto vehicle occupants. Dealers will replace the driver's frontal air bag module free of charge to resolve the concern.
The air bag control unit may corrode and cause it to malfunction, resulting in air bags that deploy when not intended, or do not deploy at all in an accident. Dealers will inspect and replace the air bag control unit as needed free of charge to resolve the concern.