Why does my Mercedes Benz engine misfire so often?

Engine misfires are one of the most common problems we see in many Mercedes-Benz cars. To be honest, it is not because MB cars are weak in this area, but because most owners forget that spark plugs are wear items and need to be replaced at the recommended intervals.

What kind of car is the 2009 Mercedes Benz GL Class?

The 2009 Mercedes-Benz GL-Class is a large seven-passenger luxury SUV available in three trim levels. The GL320 Bluetec and GL450 are equipped identically except for their power plants and wheels. The 320 comes standard with diesel power and 20-inch wheels, while the 450 boasts a V8 but downsizes to 19-inch wheels.

What was the problem with my Mercedes GL Class?

Had huge diesel fuel leak due to o-ring issues with the fuel filter, another $250 spent to fix that. Then I the air bag compressor failed, $875 to replace that, then had 1 air bag fail, another $1400. The rear power lift gated failed at cost of close to $2000 to replace it. The final nail in the coffin was the sale of the vehicle for $6500.

How many miles does a Mercedes GL450 have?

I’ve got a 2009 GL450 with 65K miles. My wife drives it for light suburban driving only. In general, we like the vehicle, but it has been in the shop at least every three months. We are now out of warranty and have had a flood of issues in the past month.

Where are misfire codes stored in a Mercedes?

Luckily for you, the misfire codes are stored in the ECU and are very easy (and inexpensive) to retrieve. To diagnose an engine misfire on a Mercedes all you need is a generic OBD II code reader that can be bought in some cases for under 20 at your local auto parts store or on Amazon’s Best Selling OBD II scanners list.

Can a clogged catalytic converter cause a misfire?

A catalytic converter that is clogged and is restricting the exhaust gasses from leaving the engine can also trigger multiple cylinder misfire. If your catalytic converter is clogged you will notice a drastic drop in fuel efficiency and real struggle getting your Mercedes to accelerate. If the cat is completely clogged your car won’t even start.

Why does my Mercedes Benz hesitate to accelerate?

-Air filter and throttle body are clean. -I haven’t changed the MAF in the 2 years that I’ve owned the car, and i tried running the car with the MAF unplugged; the problem was the same except now the idle was constantly low and rough. The problem is slowly getting worse. I’m contemplating ordering a new MAF or maybe a set of new coils..

What happens when catalytic converter is clogged in Mercedes?

If your catalytic converter is clogged you will notice a drastic drop in fuel efficiency and real struggle getting your Mercedes to accelerate. If the cat is completely clogged your car won’t even start.

Why does the engine stop working at idle?

This actuator receives information from the electronic control unit (ECU) so it knows at what RPM to keep the engine for a smooth and safe idle. When the actuator malfunctions, the engine gets no signal for idling speed and stops working.

When do Mercedes Benz motor mounts start to loose fluid?

CAUTION: Make sure no one is standing on the front or back of the car when you perform this test. Mercedes-Benz motor mounts are fluid filled instead of rubber mounts that are used on most cars. Mercedes-Benz the engine mounts start to loose fluid around the 100k mile mark.

Why does my Mercedes C class run rough off-idle?

21 people found this helpful. Hmmm, so what you’re saying is it idles ruff but passed that part of the test and runs smooth off-idle but fails that part because it’s running too rich ( too much fuel). If you had a vacuum leak at the throttle body you’ll be running lean not rich as you are now.

Why is my Mercedes Benz W210 running rough?

Many times, a lean running condition can be traced back to a cracked or torn boot in the system. A good quick way to check the overall health of the system is to take the oil filler cap off with the engine running. If the system is in good shape, the idle of the engine should drop and the car will run rougher.

What to do if Mercedes check engine light is on?

1. Turn ignition to position II. All dash lights should be on. Don’t start the car. 2. Locate the OBD-II port under the dashboard. Location of OBD II port used to retrieve Mercedes-Benz fault codes. 3. Plug your OBD II scanner and let it turn on. Use an OBD II scanner to check why the Check Engine Light is ON.

How many spark plugs does a Mercedes Benz have?

Rember that Mercedes-Benz V6 and V8 engines utilize two spark plugs per cylinder. That is typical in Mercedes-Benz engines such as M112 M113 M272 M273 found on E, C, S, CL, CLK, ML, GL, G, R, SLK Class. For example, if you have an E320 (M112 engine) or E350 (M272) your car has six cylinders but requires 12 spark plugs.

What are the problems with a Mercedes Benz?

Top 5 Mercedes-Benz no start problems 1 Engine Click, No Start 2 Engine Dies Right After It Starts 3 Car turns over, but it won’t start 4 The car makes a clicking noise but won’t start. Hint: Starter Problem or Low Battery 5 Key will not turn the ignition More

What causes a Mercedes Benz to not start?

In most cases you will get a fault code related to one of the following: 1 ECM / PCM computer failure 2 Camshaft position sensor 3 Shifter Selector module 4 Fault codes related to driver authorization or immobilizer 5 Electrical problems

Why is the battery on my Mercedes Benz not working?

Hint: Starter Problem or Low Battery This may seem obvious, but an old battery is the root of many headaches and can cause all sorts of malfunctions on Mercedes-Benz cars. How old is the battery on your Mercedes-Benz?

What kind of engine does Mercedes Benz 300E have?

The lineup now consisted of the 300D 2.5 Turbo; a 300E 2.8 sedan with a new 2.8-liter twin-cam engine; 300E sedan; 300CE coupe; 300TE wagon; and 300CE Cabriolet with a new 3.2-liter 6-cylinder engine. Rounding out the line were the 400E and limited-edition 500E, with V8 power. All models now had dual airbags.

What kind of engine did Mercedes Benz have in 1990?

The 260E sedan used a 158-horsepower, 2.6-liter 6-cylinder engine. A new 217-horsepower, 3.0-liter inline six with dual camshafts went into this year’s 300CE coupe. Other models got a single-cam 3.0-liter inline six, rated at 177 horsepower. A turbocharged 5-cylinder diesel engine arrived in spring 1990, in the 250D sedan.

How big is the Mercedes-Benz 300 E class?

Engines Engine Size (liters/cubic inches) Engine Size (liters/cubic inches) 2.5/152 Engine HP Engine HP 121 Engine Torque (lb-ft) Engine Torque (lb-ft) 165 Avail. Trans. EPA MPG (city/hwy) MPG avg. as tested

When did the Mercedes Benz 300d come out?

A 300D sedan arrived in spring of 1994, as an early ’95 model, with a new 134-horsepower 3.0-liter diesel 6- cylinder engine. 1995 300/E-Class Only a handful of equipment changes marked the 1995 models, as Mercedes-Benz proceeded with the introduction of a redesigned E-Class for ’96.

What causes a Mercedes to go into lime home mode?

If you are reading a P0301 through P0312 code plus another code, let say P0100. It is very likely that the P0100 fault code which refers to a malfunction in the mass air flow sensor circuit is also causing the misfire codes and even a limp home mode. Lime home mode means the transmission gets stuck in gear, typically in second gear.

Why does my Mercedes Benz make a clicking noise?

It requires electrical power to crank the engine. The car makes a clicking noise but won’t start. Hint: Starter Problem or Low Battery This may seem obvious, but an old battery is the root of many headaches and can cause all sorts of malfunctions on Mercedes-Benz cars.

Why does my Mercedes C320 cylinder keep misfiring?

3) Once the cylinder misfire occurred, does it keep misfiring all the time or will it misfire in certain circumstances like high rpm, high speed, fast acceleration or something? Any estimate on what would it take to fix it and any estimate on reasonable cost to have it fixed?

How to diagnose an engine misfire on a Mercedes?

To diagnose an engine misfire on a Mercedes all you need is a generic OBD II code reader that can be bought in some cases for under 20 at your local auto parts store or on Amazon’s Best Selling OBD II scanners list.

What are the most common signs of engine misfires?

The most common situation to notice misfires is on high gears, low RPM, and the accelerator to the floor. Rough acceleration is a typical sign that your engine is misfiring.

Can a bad spark plug cause an engine to misfire?

If you have separated spark plugs, unplug each coil to see if you can find out if any cylinders are not responding. Replace if you find one faulty or have a trouble code stored for one ignition coil. 2. Bad Spark Plug The second most common cause of a misfire is bad spark plugs.

Can a faulty fuel injector cause an engine to misfire?

A faulty fuel injector will cause your engine to misfire, and these can be pretty difficult to diagnose without flow testing them. Injector problems are not very common on newer cars, and because of this, you want to check out the other possible causes first, but it is absolutely worth checking.

What causes an engine to misfire in a new car?

7 Common Causes of an Engine Misfire 1 Bad Ignition Coil (New Cars) / Distributor (Old Cars) 2 Bad Spark Plugs 3 Intake Manifold Gasket Leaks 4 Low Fuel Pressure 5 Injector Problem 6 Low Compression 7 Wrong Air-Fuel Mixture

How can you tell if your car engine is misfiring?

Rough acceleration is a typical sign that your engine is misfiring. Sometimes, the engine will misfire on idle also; your engine sensors will get faulty values, and the air-fuel mixture will get messed up. This can cause a very uneven idle, which can jump up and down, and the engine may also shut off on idle.

Can a bad crankshaft sensor cause engine to run rough?

You will feel, and maybe hear, this as a brief stutter in the engine. You might feel that the engine runs rough or vibrates at idle, say, when you’re sitting at a red light. This is similar to the above in that it stems from poor spark timing. As seen with rough idling, sometimes crankshaft position sensor problems are worse at low engine speeds.

Why does my car run rough at idle?

That is to say combustion may be disrupted. You will feel, and maybe hear, this as a brief stutter in the engine. You might feel that the engine runs rough or vibrates at idle, say, when you’re sitting at a red light. This is similar to the above in that it stems from poor spark timing.

How much does it cost to diagnose a Mercedes-Benz misfire?

The cost of diagnosing the P0300 MERCEDES-BENZ code is 1.0 hour of labor. The auto repair’s diagnosis time and labor rates vary by location, vehicle’s make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour. When is the code detected? When a misfire occurs, engine speed will fluctuate.

What does a P0300 cylinder misfire code mean?

The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If no leak are found the next step is to replace the spark plugs. If the problem persists more tests needs to be done to diagnose problem, see “Possible Causes”

What are the problems with a Mercedes SL600?

Seems like a small problem, but wait until it rains. Next, air conditioning wasn’t blowing cool air and the brake warning lights were coming off all the time. There were also oil leaks, as Hoover pointed out, as well as a problem with the car’s famed hydraulic suspensions.

What happens when a Mercedes engine misfire occurs?

As soon as an engine misfire occurs on a Mercedes-Benz, you will notice poor engine performance and strange vibrations that in some cases can be felt even in the driver cabin. The first thing that comes to mind when you get an engine misfire is: “This is going to be expensive.” Take a deep breath because in most cases it doesn’t have to be.

What causes a cylinder to misfire in a Mercedes?

In most cases, a cylinder misfire is caused either due to old spark plugs that need to be replaced. A failed ignition coil or a bad spark plug wires. If none of the above fixes your misfire problem carefully analyze the fault codes, it is possible that misfire may be indirectly caused by another problem in the engine.

How does the engine control unit detect a misfire?

The engine control unit can detect a misfire in some different ways, depending on what car model and engine you have. The engine control module is using a lot of sensors to know when to ignite the spark plug and when to inject the fuel into the cylinder and to optimize the air-fuel mixture.

What causes an ignition coil to misfire in a car?

The most common problem when it comes to misfires is the ignition coil. Some vehicles have a separate ignition coil on each spark plug, while some cars have one coil with a sparking cable to each spark plug. Older cars have a distributor and, in some cases, also an ignition coil.

Can a cylinder misfire cause no other codes?

In cases where there’s a cylinder misfire code, but no other codes. The ignition or fuel delivery system may be borderline; and not yet bad enough to set a code of its own. A shorted or open fuel injector solenoid, or a shorted or open coil will usually set a code.

What causes a car engine to misfire at idle?

Worn piston rings, worn or broken valves and worn cylinder walls, as well as worn cam lobes can also contribute to the problem. When the engine misfires, you may have trouble getting your vehicle up to speed.

What happens when Mercedes diesel engine is not running?

As Mercedes DPF traps and holds soot, with time it reaches a point when it needs to be ‘emptied out’. This is done by regeneration. During this automated process, engine computer rises exhaust gasses temperature over 630°C. This burns up soot particles. However, if the engine is not running correctly automatic regeneration will not be started.

Is it OK to drive an engine that is misfiring?

Instead from that, misfires can damage other sensors in the engine like the O2 sensors. So, I would never recommend driving an engine that is misfiring for any long distances. Short distances to your mechanic workshop without putting a load on the engine is fine, but do not ignore the misfires and keep driving.

Can a 4 cylinder engine misfire on a 3 cylinder car?

If your 4-cylinder engine is misfiring on one cylinder, it may sound like a three-cylinder engine. If your car’s sound is extraordinary, it’s most likely misfires on every cycle that you can hear. So, when you suspect that your engine is misfiring, where should you start looking for the problem?

What are the signs of an engine misfire?

However, a misfire will be considered in conjunction with the following signs: 1 Check engine light 2 Engine stalling 3 Rough idle 4 Slow acceleration 5 Excessive fuel consumption 6 Hard starting the vehicle 7 Low fuel pressure 8 Low compression More …

What causes a car to misfire after 50, 000 miles?

After 50,000 miles or so, OEM carbon-core ignition wires develop too much internal resistance, which weakens the spark and increases the risk of misfire. High-mileage plug wires also can develop cracks that leak current to ground or to other wires, shorting the spark before it can reach the plug.

When do I get a misfire code on my engine?

Misfire codes do not always indicate there is an issue with the ignition system. A misfire code is set when the computer detects a situation where there is an unexpected change in crankshaft speed. With most engines, the crank sensor is the key component in determining a misfire.

How to activate Bluetooth connectivity in the 2007 Mercedes E350?

Locate the passkey on the Mercedes-Benz cradle adapter with Bluetooth. The pass code will appear on a sticker. Write down this number for future reference. Open the center console on your 2007 Mercedes E350. Slide the cradle adapter upward into the contact plate. The cradle will snap into place and make a clicking sound when successfully installed.

How do you install a cradle on a 2007 Mercedes E350?

Write down this number for future reference. Open the center console on your 2007 Mercedes E350. Slide the cradle adapter upward into the contact plate. The cradle will snap into place and make a clicking sound when successfully installed. Turn the key to the first available position. Press the button on the cradle for approximately three seconds.

How is a misfire detected in a Mercedes Benz?

This is far more effective at detecting misfires than engine systems that use the crankshaft sensor/speed analysis detection method. As with all the late-model Mercedes-Benz engine control systems, injector pulse is shut off by the PCM on the misfiring cylinders to protect the catalytic converter.

Why does my Mercedes engine misfire when I change the spark plug?

Keep this in mind especially if you change the spark plugs in your Mercedes and you are still getting an engine misfire. Fuel pressure can cause engine misfire as well.

Are there any Mercedes Benz cars that have misfire DTCs?

Car 3: 2002 S600 originally had multiple misfire DTCs that would set intermittently on all 12 cylinders. Mercedes-Benz had many problems with these vehicles setting misfire DTCs when the vehicles were under warranty and issued a special troubleshooting diagnostic guide.

The most common situation to notice misfires is on high gears, low RPM, and the accelerator to the floor. Rough acceleration is a typical sign that your engine is misfiring.

What happens when one cylinder is not firing?

When one cylinder is not firing correctly, the engine will become unbalanced, and this can cause heavy vibrations inside your cabin on acceleration or at idle. 4. Check Engine Light Modern cars have great monitoring for all the different car sensors on the engine.

What kind of engine does a Mercedes Benz have?

That is typical in Mercedes-Benz engines such as M112 M113 M272 M273 found on E, C, S, CL, CLK, ML, GL, G, R, SLK Class. For example, if you have an E320 (M112 engine) or E350 (M272) your car has six cylinders but requires 12 spark plugs.

How to know if your Mercedes C class is idle?

Check for vacuum leaks with a smoke generator injecting smoke into any vacuum line and see where the smoke comes out. That’s a leak that needs to be plugged. Other than that, there is the Idle Control Unit computer and the Idle Control Adjustment Valve, all which control the idle.

What is the misfire code on my 420?

So next most common possibility would be MAF. codes are for misfire on cylinder 3 and 5. On the 420 the trick is to swap coil packs to different cylinders and see if the misfire code follows. If so, replace the affected coil packs. I’ve had 4 coil packs fail on my 420. I also didn’t see miles.

What should I do if my engine misfires?

I have check engine electronics on and odb codes P0300, P0301 & P0306. if the misfires follow the coil. I think you have a vacuum leak since it changes with temperature. I mist the whole intake system little by little with engine starter fluid or carb cleaner (use something that does not damage oxygen sensors).

What’s the idle RPM on a Mercedes 500SL?

What is strange now is that if I start car cold, it does everything right, starts idle at about 1000 rpm then drops within a very short time to idle at about 550 rpm. All is well even while warming up but the moment I hit the gas and let off, the idle only drops to about 1100 rpms so it’s not just creeping up on its own like before.

What are the problems with a 1991 Mercedes 500SL?

Top 1991 Mercedes-Benz 500SL Problems 1 Bad Switch/Blower Motor Resistor Assembly May Cause Inoperative Heater Blower Motor 13 people have reported this 5 2 Hard/soft Tops May Develop Problems Due to Age 11 people have reported this 5 3 Transmission Oil Seals May Leak on High Mileage Vehicles 8 people have reported this 2

What to do if your Mercedes possition sensor is not working?

Don’t start the car. Press and hold the gas pedal for at least five seconds. Keep the pedal pressed. Turn ignition off but do not remove the key. Now release the gas pedal. Remove key. Wait a minute before you restart your Mercedes. This allows resetting the High and Low points of the gas pedal.

What to do if your Mercedes throttle sensor is defective?

Your options are to replace it with a new throttle position sensor. Mercedes-Benz dealerships would be happy to help you or any Indepdement mechanic. Or you can replace the throttle position sensor yourself to save money. If your throttle body is defective, you may not be able to repair it yourself.

What causes lack of acceleration in a Mercedes?

Symptoms include lack of acceleration when you press the gas pedal or vehicle trying to stall. The fuel pump is not providing the required fuel pressure to keep up with the engine demands. Mercedes may jerk during acceleration from a stop. Happen when you hit the gas pedal to the floor.

Is there a problem with the Mercedes possition sensor?

Mercedes-Benz throttle body or throttle position sensor found on C-Class, E-Class, S-Class, CLK-Class, SLK-Class may fail causing idle issues, no idle or poor acceleration. Symptoms of defective Mercedes throttle body or throttle position sensor include: A common problem that you may notice is that the car drives fine under normal acceleration.

How to troubleshoot Mercedes Benz air suspension problems?

Learn how to troubleshoot Mercedes-Benz Air Suspension Problems. You decide to buy a Mercedes-Benz, maybe an S-Class, CLS-Class, R-Class, CL-Class or E-Class. One day you hear of other Mercedes-Benz owners having suspension problems. The next day you start having air suspension problems yourself.

What does fault code p0301 through p0312 mean?

If you are reading fault codes such as P0301 through P0312, that means that most likely the problem is with one of the cylinders misfiring. This is due to a bad spark plug, spark plug wire or ignition coil issue. If you are reading a P0301 through P0312 code plus another code, let say P0100.

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