The legendary Mercedes-Benz C-Class (W204) is one of the coolest cars we've ever driven. Yes, it may seem a bit outdated today and it may be worse than newer Mercedes vehicles. But this is a classic car that is perfect for pretty much all people. Whether you are short or tall, thin or overweight, you will always find it good to drive.
Key features and my opinion about the engine
- Production years:2002-2015
- Average lifespan of M271:180,000-210,000 miles
- Fuel supply type:port or direct injection
- Power range:122-204 hp
- Fuel efficiency:bad
- Engine block material:aluminum
- Engine reliability score:medium
- The most common problems:weak timing chain, carbon buildup on valves, various leaks, fuel leaks into the oil pan.
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What are the symptoms of the timing chain issues in your W204?
The vehicle was produced from 2007 to 2014 and had 11 versions of engines, 7 of which were gasoline ones and they were presented in the US. Of course, the brightest ones are the 3.5 V6 and the 6.2 V8 for AMG versions, but it doesn't matter which engine you have under the hood of the vehicle, you can still have timing chain issues (unless it's a belt engine, but then you will probably have timing belt issues).
So, here are the symptoms that may indicate problems with your timing chain:
- the engine may start rattling suddenly - it will still work, but rattling will disturb you a lot;
- misfiring errors or just some other symptoms of a misfiring engine;
- some metal parts in the oil pan or on the dipstick;
- bad start or inability to start the engine at all;
- in most cases, the check engine light will come on;
- metal parts in an oil filter are possible if the problem is fatal;
- the engine loses its power and goes sluggishly as hell.
Well, if you experience some of these symptoms, you may be sure that one of the most probable reasons for them is the chain. It may be just stretched and still sitting in its initial place (a positive scenario) or it may have jumped a little and changed the timing (bad scenario).
In the worst-case scenario, the chain will jump a lot and the pistons will bump over valves which will lead to a very long and extremely expensive repair. In most cases, an engine swap will be a cheaper and more rational option.
Why is the chain causing problems in your Mercedes W204?
The chain may cause some trouble just because it's old and stretched. This is the most obvious reason. Have you been driving your W204 for more than 150,000 miles without looking at the chain? Well, this is the case - you need to change the chain along with the tensioner and some other parts that come in a kit.
Chains can also stretch because of some problems with your engine. For example, bad oil can cause the chain to stretch because oil is used to maintain the chain in optimal working condition and avoid overheating and other issues.
Also, in W204, your habits may be one of the reasons why your chain died so soon. If you are one of those lucky guys who got a Mercedes C-Class equipped with the manual transmission, never leave your vehicle on an incline with just the first gear on and without a handbrake on. Why? Because your car will basically hang on the chain and will stretch it pretty fast.
In other cases, bad installation or cheap parts may be the reason why the chain didn't live long. For example, if you decide to change just the chain, without its tensioners, pump, and other parts, one of the parts may fail pretty soon and stretch the chain again.
How to fix the problem with the chain in a Mercedes W204?
Your C-Class will be OK if you follow the guidelines given in the owner's manual. Replacing a chain is not recommended directly, but after 120,000 miles, you should have the valve clearance checked and measured. If it's not OK, the chain should be replaced.
We would recommend changing the timing chain in your Mercedes W204 at 120,000 miles and then changing it every 80K miles. This way, the engine can go much more and you will not kill it just because the old chain fails once.
Unfortunately, you can't do anything once the chain fails unless you are a very experienced specialist in engine overhauling and mechanical repair. We believe the best way will be to stop trying to start your engine and to have it repaired by professionals. Of course, inquire about the price of this repair, because sometimes replacing the engine will cost you the same money.
About the authors
The CarAraC research team is composed of seasoned auto mechanics and automotive industry professionals, including individuals with advanced degrees and certifications in their field. Our team members boast prestigious credentials, reflecting their extensive knowledge and skills. These qualifications include: IMI: Institute of the Motor Industry, ASE-Certified Master Automobile Technicians; Coventry University, Graduate of MA in Automotive Journalism; Politecnico di Torino, Italy, MS Automotive Engineering; Ss. Cyril and Methodius University in Skopje, Mechanical University in Skopje; TOC Automotive College; DHA Suffa University, Department of Mechanical Engineering
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