Mercedes-Benz Garage

Tumble Flap Position Sensor Replacement - C Class - W204 - Mercedes-Benz Tumble Flap Position Sensor Replacement Time: 2 hours Tab: $50 to $100 Talent: 2 Tools: T-30 Torx driver, small flathead screwdriver Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Tumble flap sensor Hot Tip: Be prepared to move things out of the way Performance Gain: Working variable resonance intake Complementary Modification: New air filter The Mercedes C350 has a variable resonance intake manifold. This manifold can switch over from long intake runners to short intake runners by utilizing switch flaps and tumbler or flap shafts. There are two shafts, one on each side of the intake manifold. If you are getting error codes from the variable system, one of the first things you should check is the tumbler flap sensor for failure. Both sensors are located at the rear of the intake manifold. While replacement in theory is easy I have never been able to si...

Cylinder Head Front Cover Replacement - C Class - W204 - Mercedes-Benz Cylinder Head Front Cover Replacement Time: 2 hours Tab: $20 to $900 Talent: 3 Tools: E10, T27, T30 Torx Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Sealant Hot Tip: Clean the surfaces really well Performance Gain: No oil leaks Complementary Modification: Reseal valve covers There are two sections to the valve covers on the Mercedes C350, the front cover (which covers the ends of the variable cams) and the top valve cover. Neither of these covers use a gasket to seal the area between the head or towers. If they start leaking it is usually from some form of damage or warping. If your front cover is leaking the best thing to do is remove it, give it a good cleaning, reseal it, and then reinstall and properly torque the cover. Reseal leaking front valve covers with this article Applies to: C350 (2007-14), SLK350 (2004-14), CLS350 (2004-14), CLK3...

Purge Valve Replacement - C Class - W204 - Mercedes-Benz Purge Valve Replacement Time: 1 hour Tab: $100 Talent: 2 Tools: Flathead screwdriver Applicable Models: Mercedes-Benz C250 (2012-14) Mercedes-Benz C300 (2008-14) Mercedes-Benz C350 (2008-14) Parts Required: Valve, hose clamps Hot Tip: Make sure you install it in the right direction Performance Gain: Pass SMOG test Complementary Modification: Change air filters A faulty purge valve or regeneration valve for fuel vapor recovery can cause you to fail a SMOG test and throw an error code in the system. The purge valve opens to allow all the vapors that are captured from the fuel tank (especially during fill ups) to be recycled to the engine to be burnt once the engine has reached certain performance parameters. There are two lines attached to the valve. Even though it is very difficult to mix them up, as they are different sizes, pay attention and make sure you install the valve in the right direction. The line out from ...

Air Pump Check Valve Replacement - C Class -W204 - Mercedes-Benz Air Pump Check Valve Replacement Time: 1 hour Tab: $150 to $300 Talent: 2 Tools: E8 Torx driver and extension Applicable Models: Mercedes-Benz W204 (2008-15) Parts Required: Check Valves Hot Tip: Use care working on old rubber hoses Performance Gain: Pass a smog test Complementary Modification: New air pump hoses If your car is not passing a smog test one of the things that could be wrong are the air pump check valves. This article will show you how to replace the air pump check valves on a Mercedes-Benz W204. Air injection check valves can cause your car to fail a SMOG test. Change them out with the help of this article. Applies to: C350 (2007-14), SLK350 (2004-14), CLS350 (2004-14), CLK350 (2005-14), E350 (2005-14), S350 (2005-14), SL350 (2005-14), R350 (2006-14), ML350 (2006-14), Viano (2005-14), Sprinter (2006-14), CLC350 (2008-14), GLK350 (2008-12) #MercedesBenzGarage

Breather Hose and Cover Replacement - C Class - W204 - Mercedes-Benz Breather Hose and Cover Replacement Time: 1 hour Tab: $20 to $80 Tools: E10 Torx Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Cover or hose Hot Tip: Use a mirror to see the oil built up Performance Gain: Smoother running car Complementary Modification: Replace air filters There is a breather hose on the top rear of the right valve cover. This hose can fail over time as well as the cover can begin to leak. If your cover is leaking or the hose has failed and is causing a vacuum leak this article will show you how to replace them. Leaking oil from the gasket on the cover can make a mess as well as cause a small vacuum issue; unfortunately at the time of writing this article you could not buy just a new gasket for the cover so if yours is leaking you will need to replace the whole cover. Replace a leaking or failed breather hose or cover with help from th...

Secondary Air Pump Replacement - C Class - W204 - Mercedes-Benz Secondary Air Pump Replacement Time: 2 hours Tab: $240 to $800 Talent: 2 Tools: E30, E25 Torx Applicable Models: Mercedes-Benz W204 (2008-15) Parts Required: New air pump Hot Tip: Use care working on old rubber hoses Performance Gain: Pass a smog test Complementary Modification: Air pump check valves If your car is not passing a smog test one of the things that could be wrong is the secondary air pump. This article will show you how to replace the air pump on a Mercedes-Benz W204 C350. The pump is connected to the motor by a mount that needs to be transferred to the new pump so be aware and do not throw the old pump out with the mount attached. You do not get the mount with the new pump. Trouble passing a SMOG test? Replace your secondary air pump. Applies to: C350 (2007-14), SLK350 (2004-14), CLS350 (2004-14), CLK350 (2005-14), E350 (2005-14), S350 (2005-14), SL350 (2005-14), R350 (2006-14), ML350 (2006-14),...

Air Injection Change Over Valve Replacement - C Class - Mercedes-Benz Air Injection Change Over Valve Replacement Time: 30 minutes Tab: $40 Talent: 2 Tools: Hands Applicable Models: Mercedes-Benz C350 (2007-14) Mercedes-Benz CLK350 (2006-09) Mercedes-Benz E350 (2006-14) Mercedes-Benz GLK350 (2010-12) Mercedes-Benz ML350 (2006-14) Mercedes-Benz R350 (2006-12) Mercedes-Benz S350 (2006, 2012-13) Mercedes-Benz SLK350 (2005-14) Parts Required: Change over valve Hot Tip: Clean the area before removing the sensor Performance Gain: Better control of fuel injection and engine timing Complementary Modification: Replace crankshaft position sensor If your car is not passing a smog test, one of the things that could be wrong is the air injection change over valve. This article will show you how to replace the valve on a Mercedes-Benz W204. Air injection change over valves can cause your car to fail a SMOG test. Change them out with the help of this article. Applies to: C350 (20...

Air Conditioning Compressor Replacement - C Class -W204 - Mercedes-Benz Air Conditioning Compressor Replacement Time: 4 hours Tab: $600 to $1,100 Talent: 3 Tools: E12 Torx socket, extensions, universal joint, T45 Torx, 17mmsocket Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: A/C compressor Hot Tip: Inspect for leaks before replacing the compressor Performance Gain: Working A/C Complementary Modification: New engine air filters A word of note before you start: The A/C system is charged with a refrigerant that is both dangerous and illegal to discharge into the atmosphere. If you are going to be working on the system make sure you have the refrigerant properly evacuated and reused or disposed of. There are all kinds of things that can go wrong with the A/C system on your Mercedes including something as simple as needing a recharge. This article is not intended to instruct you on the complete A/C system and how to check it out...

Oil Cooler and Seal Replacement - C Class - W204 - Mercedes-Benz Oil Cooler and Seal Replacement Time: 1 hour Tab: $10 Talent: 2 Tools: T30 Torx, torque wrench Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Oil cooler seal Hot Tip: Clean both surfaces well Performance Gain: No leaks Complementary Modification: Oil and filter change The oil filter housing has an oil to water cooler attached to it to help cool the engine oil. While this simple design does a great job of helping control the engine oil temperature it has a tendency to develop leaks over time. This is usually caused by the seal drying out and installing a new seal usually solves the problem. You will need to drain the coolant from the radiator as the coolant flows through the cooler and needs to be removed before you can replace the seal. Please see our article on coolant drain and flush. If your oil cooler is leaking it is probably the seal; this article wil...

Camshaft Magnetic Adjuster Replacement - C Class - W204 - Mercedes-Benz Camshaft Magnetic Adjuster Replacement Time: 2 hours Tab: $35 to $3,200 Talent: 2 Tools: E8 Torx, T30 Torx, small flathead screwdriver Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Camshaft adjuster magnet Hot Tip: Clean the area before removing the magnet Performance Gain: Better control of fuel injection and engine timing Complementary Modification: Replace crankshaft position sensor Your fuel injection computer (DME) may output a code that indicates faulty camshaft adjuster magnets. The camshaft adjuster magnets are an essential part of the variable camshaft system on the vehicle. If they are not operating properly, your car can run very rough. There are four camshaft adjusters on the C350 motor, one for each intake and one for each exhaust cam. The adjusters are located at the front of the motor on the end of each cam housing. Replacement of three o...

Air Oil Separator Replacement - C Class - W204 - Mercedes-Benz Air Oil Separator Replacement Time: 1 hour Tab: $15 to $45 Talent: 1 Tools: T10 Torx Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Air oil separator Hot Tip: Use caution working with old hoses Performance Gain: Car runs like normal again Complementary Modification: Replace vacuum hoses The air oil separator on the C350 can wear out and fail over time. Most of the time the gasket fails on the separator and starts leaking oil onto the head. If your separator is failing replacement is quick and easy. Replace a leaking or failed air oil separator with help from this article Applies to: C350 (2007-14), SLK350 (2004-14), CLS350 (2004-14), CLK350 (2005-14), E350 (2005-14), S350 (2005-14), SL350 (2005-14), R350 (2006-14), ML350 (2006-14), Viano (2005-14), Sprinter (2006-14), CLC350 (2008-14), GLK350 (2008-12)

Cam Bore Expansion Plugs Replacement - C Class - W204 - Mercedes-Benz Cam Bore Expansion Plugs Replacement Time: 1 hour Tab: $5 to $15 Talent: 1 Tools: Trim removal tool or small flathead screwdriver Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Plugs Hot Tip: Use a mirror to see the oil built up Performance Gain: No leaks Complementary Modification: Replace air filters The 350 series V6 engines in the Mercedes-Benz cars are known for leaking oil from the rear of the camshaft area. At the rear of these engines are three cam bore expansion plugs that seal up the covers and allow for expansion. These plugs dry out and start leaking over time and need to be replaced. The plugs are cheap. Replacing them takes no time at all yet most shops charge a lot of money for this repair. Even if you are just starting out on DIY work on your car you can save yourself a lot of money by doing this repair yourself. First check that the plugs...

Oil Housing and Seal Replacement - C Class - Mercedes-Benz Oil Housing and Seal Replacement Time: 2 hours Tab: $10 to $190 Talent: 2 Tools: E12, E10 E Torx sockets, 17mm socket Applicable Models: Mercedes-Benz W204 (2008-15) Parts Required: Oil housing seal, thermostat seal, coolant, oil Hot Tip: Clean both surfaces well Performance Gain: No leaks Complementary Modification: Oil and filter change The oil filter housing has a tendency to start leaking oil and/or coolant over the years. This is usually caused by the seal drying out and failing. Installing a new seal usually solves the problem. While this is not a big job in itself you do need to remove several components to get the housing out. This is a great time to change your oil and filter. You are going to need to drain the oil to remove the oil filter housing so you might as well change everything while you are at it! You will also need to drain the coolant from the radiator as the coolant flows through the cooler and...

Crankshaft Positioning Sensor Replacement - C Class - W204 - Mercedes-Benz Crankshaft Positioning Sensor Replacement Time: 2 hours Tab: $20 to $40 Talent: 1 Tools: T30 Torx Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Crankshaft positioning sensor Hot Tip: Use a mirror Performance Gain: Smoother running car Complementary Modification: Replace Camshaft positioning sensors Your fuel injection computer (DME) may output a code that indicates a faulty camshaft position sensor (CPS). This important sensor tells the car's computer where the flywheel is located in relation to the combustion cycle. The DME takes the signals from both the cam position sensor and crankshaft position sensor, and calculates when to fire the fuel injectors and spark plugs. If the crankshaft position sensor is not operating properly, your car will run very erratically or perhaps not at all. Replacement of the sensor is not as easy as the camshaf...

EGR Change Over Valve Replacement - C Class - W204 - Mercedes-Benz EGR Change Over Valve Replacement Time: 1 hour Tab: $40 to $100 Talent: 1 Tools: Hands Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: EGR change over valve(s) Hot Tip: Order some vacuum hose before you start Performance Gain: Pass a SMOG test Complementary Modification: Change the oil filter If you are having trouble passing a SMOG test and getting an error code that the EGR change over valves are faulty you can replace them yourself, though you are going to have a fair amount of work ahead of you. The valves are located at the front bottom of the intake manifold and cannot be accessed without removing the intake from the engine. Please see our article on intake manifold removal for step-by-step instructions. If you are replacing the valves it is a good idea to order some replacement vacuum hose along with the valves. The rubber vacuum hose that attaches the ...

MAP Sensor Replacement - C Class - W204 - Mercedes-Benz MAP Sensor Replacement Time: 30 minutes Tab: $30 to $50 Talent: 1 Tools: Hands Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: MAP sensor Hot Tip: Careful working with the hose Performance Gain: Working sensor Complementary Modification: Change the oil filter The MAP sensor or Manifold Absolute Pressure sensor provides instantaneous manifold pressure to the ECU. This information is used along with the MAF sensor to determine fuel metering. Failure of the MAP sensor is usually associated with a rough running motor along with a check engine light. On some C350s the error code is P0106 but check to make sure on your own particular vehicle. While the MAP sensor is not that inexpensive it certainly is quick and easy to replace. Replace a failed MAP with help from this article Applies to: C350 (2007-14), SLK350 (2004-14), CLS350 (2004-14), CLK350 (2005-14), E350 (2005-14), S...

Tumble Flap Actuator Repair - C Class - W204 - Mercedes-Benz Tumble Flap Actuator Repair Time: 1 hour Tab: $300 Talent: 1 Tools: T30 Torx, small flathead screwdriver Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Actuator repair kit, silicone grease, blue Loctite Hot Tip: Lube the ball cups Performance Gain: Better engine performance Complementary Modification: New injector O-rings Along with the variable intake runners on the intake manifold on the Mercedes C350 the manifold also has tumble flaps. These tumble flaps on each side of the intake help swirl the air entering the combustion chamber helping with performance and economy. While the system works reasonably well, over time carbon will build up on the flaps and cause more stress on the plastic actuator arm than the system was designed to handle. This usually results in the failure of the plastic pivot lever where it meets the actuator arm. If you drive the car long ...

Spark Plugs and Coils Replacement - C Class - W204 - Mercedes-Benz Spark Plugs and Coils Replacement Time: 2 hours Tab: $60 to $400 Talent: 2 Tools: T30 Torx driver, 5/16th spark plug thin wall socket extensionsand universal joints, small flathead screwdriver Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Spark plugs, coils if needed Hot Tip: Work on a cold engine Performance Gain: Better mileage Complementary Modification: New air filters Replacing the spark plugs on your Mercedes-Benz C350 is recommended routine maintenance though be it at much longer intervals than before. Mercedes recommends replacing the spark plugs on C350 models every 100,000 miles. With all the major engine design changes over the years, spark plugs now last up to three times as long as they did in years past. This is good and bad. It means you save money and time not having to service them so frequently, but run the risk of a spark plug seizing in t...

Engine Air Filter Replacement - C Class - W204 - Mercedes-Benz Engine Air Filter Replacement Time: 30 minutes Tab: $20 to $60 Tools: T25 Torx driver, rags Applicable Models: Mercedes-Benz C350 (2008-15) Mercedes-Benz GLK350 (2010-15) Parts Required: New air filters Hot Tip: Wipe down the inside of the airbox Performance Gain: If the old filter is really dirty, you'll pick up some power Complementary Modification: Change cabin air filter Every 10,000 miles or so, you should change the two engine air filters in your Mercedes-Benz C350. The air filters protect the air intake system, valves, pistons, cylinder walls, and engine oil from dust and debris that can be sucked in under normal operation. Replacement is a snap and should take only 30 minutes or so. There are two engine covers on the C350 along with two air ducts that you will need to remove to change the air filters. Removal is simple and easy. You only need a T25 Torx New to working on your car? Not sure where...

Camshaft Position Sensor Replacement - C Class - Mercedes-Benz Camshaft Positioning Sensor Time: 1 hour Tab: $40 to $900 Talent: 2 Tools: E8 Torx, small flathead screw driver Applicable Models: Mercedes-Benz W204 (2008-15) Parts Required: New camshaft position sensor Hot Tip: Clean the area before removing the sensor Performance Gain: Better control of fuel injection and engine timing Complementary Modification: Replace crankshaft position sensor Your fuel injection computer (DME) may output a code that indicates a faulty camshaft position sensor (CPS). These important sensors tell the car's computer where the cams are located in relation to the combustion cycle. The DME takes the signals from both the cam position sensors and crankshaft position sensor and calculates when to fire the fuel injectors and spark plugs. The sensors also work in conjunction with the variable cams. If the camshaft position sensors are not operating properly, your car will run very er...

Oil and Filter Change - C Class - W204 - Mercedes-Benz Oil and Filter Change Time: 1 hour Tab: $60 to $200 Talent: 1 Tools: Oil filter removal tool, 13mm wrench, 8mm socket, floor jack, jack stands, wheel chocks, safety glasses, torque wrench Applicable Models: Mercedes-Benz C350 (2008-15) Mercedes-Benz GLK350 (2010-15) Parts Required: Oil and Filter Hot Tip: Get the engine warm before you drain the oil Performance Gain: Longer engine life Complementary Modification: Flush your cooling system One of the most common tasks to perform is replacing your engine oil. Frequent oil changes are perhaps the most important procedure you can do to maintain and prolong the life of your engine. With the better oils that are available today, the requirement for frequent changes is diminishing. Even though Mercedes Benz recommends oil change intervals that are much further apart than in the past, I usually recommend that you keep the changes under the 5,000-mile limit. If you don't ...

Wiper Blade Replacement - C Class - W204 - Mercedes-Benz Wiper Blade Replacement Time: 15 minutes Tab: $35 Talent: 1 Applicable Models: Mercedes-Benz W204 (2008-14) Parts Required: New wiper blades Hot Tip: Clean windshield before installing new blades Performance Gain: Better visibility in inclement weather Complementary Modification: Clean windows One often overlooked wear item on your car is the wiper blades. This is one of those things that can easily ruin your day if the weather suddenly turns bad. Replacement of the blades is very easy and should take no longer than 15 minutes. If you live in a wetter climate, then you'll understand the importance of wiper blades that work well. If running the wipers just streaks the windshield, it's time for new blades. Lower quality blades tend to dry out or crack quicker than quality ones. Quality blades are more expensive, but they last longer and do a nicer job of keeping the water off the windshield. Most wiper blades f...

Valve Cover Removal - C Class - W204 - Mercedes Benz Valve Cover Removal Time: 4 hours Tab: $20 Talent: 1 Tools: T30, T25 Torx, E10 Torx, 17mm wrench Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Sealant Hot Tip: Clean around the covers before removing Performance Gain: No oil leaks Complementary Modification: Replace worn out hoses The valve covers on the C350 have no gasket between the cover and the head. There is only a thin film of sealant used to seal up the top of the motor. The cover is also used to hold the cams in place and incorporate the journal for the cams. The covers are also not interchangeable with other heads so if you damage it while working on it you need to replace the head as well as the cover. For this reason USE great care! The procedures for replacing the left and right side are very similar but do have a few differences that are pointed out below. You have to move different accessories out of the ...

Knock Sensors Replacement - C Class - W204 - Mercedes-Benz Knock Sensors Replacement Time: 30 minutes Tab: $35 to $70 Talent: 2 Tools: E10 socket, torque wrench Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: New knock sensors sensor, intake manifold gasket Hot Tip: Don't work on a hot engine Performance Gain: Piece of mind on engine knock Complementary Modification: New injectors There are two knock sensors on the Mercedes C350 and they play an important part of the engine management system. The sensors detect knock or ping in the motor, which is pre detonation and can cause serious and expensive damage to the motor. If knock is detected the sensor will tell the management system of the engine to severely retard the ignition. Besides an error code you will notice a lack of power and throttle response. The sensors are easy to replace once you get access to them. Unfortunately, you will need to remove the fuel rail, injec...

Oil Level Sensor Replacement - C Class - W204 - Mercedes-Benz Oil Level Sensor Replacement Time: 3 hours Tab: $30 to $50 Talent: 1 Tools: 13mm wrench, 8mm socket, E10 Torx, extension, floor jack, jackstands, wheel chocks, safety glasses, torque wrench Applicable Models: Mercedes-Benz C350 (2008-14) Mercedes-Benz GLK350 (2010-14) Parts Required: Oil level sensor, sealant, oil Hot Tip: Do NOT use anything metal between the mounting surfaces Performance Gain: Working sensor Complementary Modification: Change the oil filter If your oil level sensor has failed you will have to remove the oil pan to replace it and then you will need to clean the mounting surfaces really well and use a good high quality sealant. I recommend Drei Bond 1209. I have used this for years with great results, and it is available at Pelican Parts. Make sure to carefully follow the instructions on the sealant you choose to use and allow it to dry and seal completely. Also you do not need to use a lo...