​Mercedes C Class W204 Service



Administrator World Garage

Mercedes-Benz C-class (body W204) is built on the same nodes and units as the older brothers in the brand. Does this unification mean a similar margin of safety and high reliability?

All cars with a body W204 — originally from Germany. Sedans and station wagons removed from the Assembly line in 2013, but a relatively fresh coupe is still available.

The car is not popular among hijackers — engineers could not waste energy on a very effective and complex, multi-component immobilizer.

The quality of the paintwork is good. If you find defects, it is only in the form of traces of unprofessional repair. The structure of the body is quite simple, so the repair does not require intricate technologies and tools.

How Mercedes-Benz E-class gets along in a taxi

The greatest distribution was received with engines of 156 and 184 forces. Practice has shown that the degree of forcing does not affect the resource of individual components and the motor as a whole.

We have already written about the problems of 184 HP engines in Mercedes E‑class, working in a taxi (ZR, 2014, № 7). All of this, albeit to a lesser extent, applies to all in-line gasoline engines C‑class.

The primary sore is the timing. Sooner or later, the chain is stretched because of the wear of the links, although it is designed for the entire life of the motor (the regulations do not even provide for checking its condition). The problem will be reported by the check lamp and the increased engine noise. It's good that stretching is not usually leap of the chain on the teeth and to meet the pistons with the valves.

Another weak link in the timing drive is the phase shifter couplings on both camshafts: the stops of the lead mechanism are broken. The motor again begins to work noisier, and during start-up the crackle is heard. Most often, at the time of stretching the chain expires and one of the couplings. If you do mind, then you need to change the time all the problematic nodes timing, not to open it again. Usually these troubles occur after 50 000 km, but it happened that the couplings died after 25 000 km. In this case, cases of re-replacement of timing elements are extremely rare.

Another common sore is the leak of the oil filter module.

Engine oil: life, replacement and uncertainties

The mechanical supercharger is very reliable. The only drawback is the increased noise level. Turbocharging also has a good resource: the service does not recall cases of its replacement. In addition, more frequent oil changes (every 10,000 km) will help to extend the service life of the turbine — to avoid the coking of its oil tubes.

Atmospheric gasoline engines V6 less popular. They are subject to the same problems with the timing drive, but to a lesser extent and at high mileage. There are oil leaks. After 60,000 km, the plugs at the rear of the unit heads on the transmission side begin to leak. Occasionally noted misting of the gaskets of the valve caps. On previous machines the control module is located in the decorative panels of the engine and suffer from overheating (often shedding items from the Board). There are workshops that are tolerable money to repair the module, out of order.

For all gasoline engines is characterized by the freezing up of the elements of the crankcase ventilation system. If you do not warm up the engine in the cold before driving, the oil begins to go directly into the intake system. The car is not available warning light: oil pressure (there is only a gauge of his level), so the drivers sometimes do not notice problems until the jamming of the motor. Such troubles happen not only with "Mercedes". BMW due to the frozen ventilation system, the pressure in the crankcase increases so much that sometimes the oil seals are squeezed out and the oil is thrown out. Even if you notice the indication of the dangerous level in time, do not be lazy to replace some of the elements of the ventilation system — just in case.

Mercedes-Benz C-class (body W204). When freezing the crankcase ventilation system on the V6 motors change its main part — the oil separator module on the engine block. But in inline engines often require replacement of the valve and the pipes that much time.
Does not possess the resource and attachment drive belt and rollers. On gasoline engines they are changed after 50 000-60 000 km because of the whistle.

The electronic thermostat is also short-lived. It sticks in the open position. Usually you can only understand it in the winter (system doesn't issue errors) — slow warm-up of the motor.

Pandora's box

Until 2010, paired with in-line gasoline engines worked 5-speed hydro mechanical "automatic". It appeared in 1996, has undergone several upgrades and is considered quite reliable: it lives up to 200 000-250 000 km — provided that there will not be several problems.
V6 motors have different volumes, but do not differ externally. In the picture on the left — the unit of the restyling machine. The decorative cover was changed, the engine control unit was moved to the side.

The main is related to the cooling system common to the box and the engine. It happens that to 100 000 km antifreeze penetrates into the box, which is why the "machine" begins to twitch and, if you do not pay attention to it, dies quickly. It is bad if the radiator is clogged with dirt: the box is sensitive to overheating. The usual interval of washing the radiator with a full removal — 60 000 km or every three years.
Since 2010, the five-stage was replaced by a seven-stage unit created on the basis of its predecessor: an additional planetary series and a package of frictions were added to the box. The more complex the site has become less reliable. The problem of the cooling radiator, which drives the antifreeze into the box, remained unsolved; in addition, the unit began to suffer more from overheating. The first thing is to die a little, the clutch of the higher gear. In addition, the control Board located inside the node (the control unit itself is located outside) may fail at any time.

Most of the problems happen because of illiterate operation — for example, when the reverse gear is turned on, without waiting for the machine to stop completely. In such modes, the mechanical elements of "automata" suffer from shock loads.

Regulations prescribe the replacement of oil in the box every 60 000 km, and to reduce this interval has not washed away.

In the front suspension, adjustable wheel bearings are used, which require maintenance at each maintenance. If you do not adjust them, the backlash will be so large that the brake disc will start to touch the caliper bracket — repair will cost a pretty penny.

Through 60 000-80 000 km die silent blocks trailing arms. They are available as individual parts.

To 100,000 km give up and start banging on the front shocks. Usually they are changed immediately with the support bearings, which by this time, too, very tired.

In the rear suspension to 60 000-80 000 km need to change the silent blocks of the front support beam. It's the only weak link. In General, the reliability of the front and rear suspension can only envy.

Front brake pads enough for 30 000 km, rear — 45 thousand. In winter, possible increased wear of the rear pads due to the active work of the stabilization system.

Mercedes-Benz C-class (body W204). Changed control Board, a seven-speed automatic that install when replacing, the old are living longer — at least three years. The benefits of changing the supplier of spare parts are evident.

Changed control boards seven-step "automatic", which are installed when replaced, live longer than the previous — at least three years. The benefits of changing the supplier of spare parts are evident.

Differential does not cause much trouble. Seals reducer worried 150,000 km, and cases of replacement of the anther actuator unit.
With 4MATIC all-wheel drive transmission problems will not arise, except that to 100 000 km may require replacement of the anther drives and the front gearbox oil seals. Even the 3.5 l motor is not able to harm the clutch in the distributor.

With steering the situation is ambiguous. On the one hand, the power steering and the rail almost do not cause problems: nothing knocks, does not flow. Everything is relatively smooth with rods and tips. Trouble lurked in an unexpected place — in the lock of the steering shaft. In a "perfect" moment, it may jam without the ability to rotate the ignition key.

On previous models, the repair meant replacing the entire steering column. On the updated machines, the engineers made the unit collapsible: the blocker can be replaced separately. But the question of durability is not solved. Since the blocker belongs to the anti-theft system, it can only be ordered and changed from an authorized dealer.

Zone of comfort

"Crickets" in the cabin — a very rare thing, as well as electrical failures. Sometimes the CD drive of the audio system fails. Other problems are mainly related to the ingress of moisture on the control units (for example, when washing too thoroughly) and their subsequent corrosion.

In inline gasoline engines often flowing oil filter module at the junction of plastic and aluminum. With sudden changes in temperature (usually in winter), the contact surface simply warps.

In inline gasoline engines often flowing oil filter module at the junction of plastic and aluminum. With sudden changes in temperature (usually in winter), the contact surface simply warps.

Air conditioning works without complaints. Compressor replacement cases are rare. As a rule, every two years it is necessary to wash the radiator (without removal can not do) and refuel the system.

The front optics are not subject to melting or fogging. On previous machines periodically fail ballasts xenon in the headlights. On the updated such problems are not present, but often the LEDs in the headlights Shine a different color. The manufacturer does not consider this a defect, so no service shares are not carried out.

Rear lights also do not cause problems — except in rare cases of melting connectors on the boards.


Typically, the owner C‑class simply goes to scheduled maintenance and change the consumables. But if there are serious problems, it will not seem enough — repair of roads!

Mercedes-Benz C-class (body W204) is built on the same nodes and units as the older brothers in the brand. Does this unification mean a similar margin of safety and high reliability?

Administrator World Garage


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