Mercedes-Benz M274 Engine Timing Chain

Background

Mercedes-Benz has a long history of manufacturing highly reliable and powerful V6, V8, even V12 engines. They are some of the most famous and durable engines in  the Euro world.

How good are their 4 cylinder engines you ask? Not that great, is the truthful answer. One of the areas where we see frequent issues is the timing chain.

The M274 is a very capable engine, with great features. It boasts:

- All aluminum construction, head and block

- Turbocharging

- Direct Injection

- Variable Camshaft Timing

It's the way of the world, man. 2 liter 4-cyl turbos are here to stay.  As it is in such widespread use, its weak spots are well-known, and proven solutions have been developed to address them. Having worked in hundreds of them, we at CarHavn EuroTech know them very well.

Like a fine Swiss watch, your engine has a precise internal mechanism where the power generated in the pistons is transmitter to the camshafts. The timing chain job is to transfer that power to the crankshaft, which turns the transmission. This needs to happen very precisely, as the engine turns approximately 500-7000 times a minute.

The Issue

Even though timing chains were supposed to be lifetime, reality has shown that they need to be replaced in the M274 engine need to be replaced every 100K miles. This job includes the intake and exhaust camshaft sprockets, guides, tensioners, and chains.

Symptoms

A failing timing system has some specific signature symptoms in this engine.

• Rattling or whine in the timing chain area
• Elongated crank times (sometimes)
• A Check Engine Light on (sometimes)
• Diagnostic Trouble Codes set in the car's computer (sometimes), including some of the following:
• P001685 - The position of the intake camshaft  (cylinder  bank 1) is implausible relative to the position of the crankshaft. There is a signal above the permissible limit value.
• P034100- The position sensor for the intake camshaft (cylinder bank 1) has a malfunction.
• P001177 - The position of the intake camshaft (cylinder bank 1) deviates from the specified value. The position cannot be reached.

Repair

This is a major repair that needs a highly-trained MB mechanic, very specific high quality parts, specialist and expensive tools, and a laptop with xentry official MB software to perform final adjustments.

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Additional Work

When doing the timing chain, a number of parts need to come out. We always advise our guests to take advantage of the opportunity to save on labor, and upgrade parts like water pump, thermostat, drive belts, coils, and spark plugs, oil filter housing gasket, valve cover gasket. These can be done for the parts price alone, or minimal additional labor.

Result

A smooth running M274 with no codes! All of our customers can feel the difference in the way the car drives, but most importantly, you will be avoiding the high and expensive risk of a massive mechanical event in your engine.