Mercedes W124 Wont Start? Here’s Quick Solutions to Most Common Problems

Intro

As a skilled car mechanic with over two decades of experience, I’ve helped plenty of people struggling when their Mercedes W124 Won’t Start. And let’s be honest, not being able to start your car when you need to drive is incredibly annoying.

But don’t worry, you’ve come to the right place, no need to keep googling searches like “starting Mercedes problems“, I got you covered. My name’s Robby, a certified auto mechanic with over two decades of experience, and in this article, I’ll outline the frequent reasons for why your W124 doesn’t start. I’ll detail all the commonplace suspects so you can pinpoint what’s causing issues, plus what to do to resolve each specific situation. Drawing on my two decades of firsthand experience, I’ll provide usable repair advice to get your Mercedes W124 starting again ASAP!

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Why Won’t My a Mercedes Start?

Mercedes W124 wont start

Before we tackle the list of possible issues and solutions, it’s key to first gain an understanding of the core problem. When you climb into your Mercedes W124 and realize “it won’t start!”, there could be several things causing the headaches. Maybe the engine isn’t cranking at all, or possibly it’s turning over partially yet not igniting. Or you might hear clicking when you try to start it, but ultimately nothing happens. Each scenario can indicate various mechanical issues.

Common Reasons Why Your Mercedes W124 Won’t Start

There are numerous reasons why your W124 won’t start. Typical causes cover a weak or drained battery, broken alternator, starter motor complications, fuel system problems, plus electrical or wiring issues. Each of these issues can show up differently, needing specific methods of troubleshooting and fixing to get you back on the open road ASAP. All of which, we’ll delve into.

Symptoms of a Mercedes W124 That Won’t Start

Spotting these red flags will lead you to the main mechanical problem. For instance, when you turn the key or press the start button and you hear it clicking but no ignition, it often means a problem with either fuel delivery or ignition issues.

Analysis of The Reasons Why Your Mercedes W124 Won’t Start

The first step in fixing the no-start headache is pinpointing the specific source of the problem. So let’s take a closer look at the most frequent reasons behind the W124 failing to start when you turn the key.

Battery Issues in a Mercedes W124

car wont start but battery is good
Image Credit: MechanicAnswer.com

In the majority of cases, the most frequent reason a Mercedes W124 won’t start comes down to battery troubles. Specifically, a drained or weak battery prevents the engine from turning over. The car’s battery delivers the required power to start the engine and energize all your electronics. Signals of a failing battery include labored or difficult cranking, faint headlights, or a warning light illuminated on the dash. A battery charger can recharge a dead battery if you don’t have the help of another vehicle to jump start it, but do have an electrical socket nearby like at home.  And a portable jump starter lets you charge p the battery without another vehicle, and by the roadside without the need for an electrical socket, so you are never stuck.

Alternator Problems in a Mercedes W124

car wont start alternator

The Alternator keeps the battery charged by harnessing engine power while driving. A worn out alternator can easily stop your Mercedes W124 from starting since it fails to recharge the battery, draining it fully so that one day you hop in your wheels and it simply can’t start. Clues of a faulty alternator can be an illuminated battery or alternator caution light on the dash, dull headlights while idling, or a whirring noise from the engine while running.

Starter Motor Failures in a Mercedes W124

car wont start wont turn over

The starter motor is key to cranking the engine when you go to start up your Mercedes. In the event of starter problems, the engine may fail to crank, keeping your W124 from starting. Listen for clicking sounds when you turn the key or grinding as you try to start it, which could indicate starter issues.

Fuel System Issues in a Mercedes W124

car wont start fuel filter

This isn’t about running out of gas like a silly goose. Instead, it’s problems in the fuel system itself potentially leaving your W124 unable to start. Your car uses gas uses fuel to mix with air and runs the engine. So problems here like a clogged fuel filter or damaged fuel pump relay can result in the engine is unable to get the fuel it needs to start. Fuel injectors can also get clogged over time, so consider a fuel injector cleaner like Red Line to clean them out and improve starting.

Electrical System or Wiring Problems in a Mercedes W124

car wont start electrical issue
Image Credit: MechanicAnswer.com

Ok, well yes that image is a joke, but I want to emphasize today’s cars depend greatly on electronics, opening up the number of things that can go wrong. Even in older models, the usual suspects include blown fuses, spark issues, damaged ignition switches, or broken sensors. Electrical issues and electronics like these may prevent your Mercedes W124 from starting. Be on the lookout for intermittent starting, warning lights, or failure to crank as hints of an underlying electrical problem. Pinpointing and fixing these typically requires an experienced mechanic near you.

Solutions: Let’s Get Your Mercedes W124 Starting Again!

If you think you might know what the issue may be, it’s time to figure out the reason behind your car’s starting failure, and then the next step is to attempt to fix the problem. Here’s advice for the common issues we’ve talked about already:

How to Identify and Fix Battery Issues in a Mercedes W124

car not starting but battery is fine

If you believe a battery issue is to blame for your Mercedes’s difficulty cranking, first check the battery terminals Verify they are corrosion-free, secure, and correctly connected. If the terminals are in fact corroded, try scrubbing them with a baking soda and water mixture.

Once you have checked the battery terminals, you can check to see if the battery is just out of charge, or worse, it’s old and weak, or dead and needs to be replaced. For this, you can charge the battery in a few different ways:

If the battery charges fully and performs as expected, the issue may be resolved. However, if the battery has aged or lacks capacity, replacing it will be necessary. Otherwise, even sufficiently charging it to start your W124 may only provide temporary relief before it likely runs out of power again soon. Using a multimeter or OB2 scanner to evaluate the battery’s condition can determine if it’s worth preserving or requires replacement. Suitable replacement batteries for your specific Mercedes can be found on Amazon here by entering your vehicle details to filter for the right fit and choosing a highly-rated seller.

Robby Recommends:

Portable Car Battery Jump Starter Charger - NOCO Boost Plus GB40

At Home Battery Charger - YONHAN - Fully Automatic

Jumper Cables by Energizer for Car Battery - Heavy Duty

NOCO Boost Plus GB40 1000A UltraSafe Car Battery Jump Starter

YONHAN Battery Charger Fully-Automatic

Energizer Jumper Cables for Car Battery, Heavy Duty

If charging your W124’s battery fails to solve ongoing issues like frequent draining and recharging even after installing a new battery, an underlying problem likely causes the excessive drain. Professional diagnostic services would then be needed to inspect and identify the root cause. You can also consult a mechanic online through us or obtain an instant quote from a mobile mechanic.

How to Identify and Fix Alternator Problems in a Mercedes W124

Car wont start replace alternator needed

If you think the alternator is the reason your vehicle won’t start, a test can confirm. If you can temporarily get the car running (you may need a jump start), with the engine on, detach the positive battery terminal. It’s probably the alternator if the engine conks out soon after disconnecting the positive lead. Keep in mind though this test can be risky and mess up sensitive electronics in your ride, so seeking advice from a qualified mechanic in your area or online is best prior to trying it.

If you figure out that the alternator is the problem, it’s a case of having it replaced. I recommend consulting an online or local mechanic as they will advise you on how difficult the repair is for your specific model, and you can work out if you want to try it yourself, or with the advice of an online mechanic

If you do want to try it yourself or take it to a local garage, you can often buy the replacement parts yourself cheaper than at the garage, but you need to know what to get for your model of Mercedes W124. You find all the information you need about your specific vehicle by searching online for something like “free Mercedes vin reports“, which is a purchasable report, that will give the specs for your vehicle and which parts are compatible, and then you can go get the alternator parts you need. However, an easier option is, Amazon probably has the alternator you need online, at a cheaper price, and their site easily shows which ones will go in your specific car model. Check the Amazon alternator page here

How to Identify and Fix Starter Motor Problems in a Mercedes W124

starter motor issues in a ford

If you wonder if the starter motor is the root cause for your W124 failing to start, listen for a clicking sound when you turn the ignition key. If present, but the engine does not turn over, the starter motor likely requires replacing. You can take it to a local garage and have them repair it, or repair it yourself with the help and advice from an online mechanic guiding you. 

If you need it, one of the cheapest and easiest places to get a new starter motor, for your exact vehicle model is on the Amazon here.

How to Identify and Solve Fuel System Problems in a Mercedes W124

clogged fuel filter car wont start

If you think a fuel system issue might be causing the no-start, tune your ears for the fuel pump noise when you turn the key to “on” before attempting to start the car. The pump should make a quiet humming for a few seconds. If you can’t hear that noise, the fuel pump could be faulty. Problematic starting, stalling, or poor throttle response may also result from a problematic or clogged fuel filter. Filter and pump issues usually require a professional mechanic to diagnose and fix them properly, often using fuel pressure testing and precise diagnostic equipment. Later in this article, I detail the best ways to get help from a local Mercedes mechanic near you. 

How to Repair Electrical or Wiring Problems in a Mercedes W124

fuses to check when car wont start

If you think it’s an electrical circuitry problem, first examine the fuses for the ignition system, and swap out any that have blown. If your W124 starts after this, it was a successful, cheap fix! But if your Mercedes W124 refuses to start, even sometimes, the ignition switch itself could be faulty. Warning lights on the dashboard could additionally mean a faulty component. These can be intricate problems needing a professional mechanic to identify and fix (see below advice on local mechanics).

How to Prevent Starting Issues in a Mercedes W124

As my dad used to say: “An ounce of prevention is worth a pound of cure”. Here’s how to prevent future troubles starting your W124:

Regular Maintenance of Your Mercedes W124

Regular maintenance on car to prevent starting issues

Regular maintenance is critical to avoiding issues, including oil changes, checking the battery, cleaning terminals, replacing the fuel filter as needed, and having a mechanic check over the car regularly. If unsure about maintenance for your model, consult a mechanic locally or online for guidance.

Drive Your W124 Regularly

drive regular to avoid car troubles

If your Mercedes W124 happens to sit motionless in your garage or front yard for extended times without being driven, the battery can decrease as it is not being recharged by the engine running, through the alternator. Try your best to use your Mercedes W124 regularly to maintain a charged battery. If you remember you haven’t driven your car in a while, take it for a brief spin around town to ensure there is still a charge left.

Note: Letting the battery entirely drain is also bad for its longevity, so try to avoid that.

Pay Attention to Warning Signs

Check Engine Control Light on a Vehicle Dashboard

If you notice any abnormal things like unusual sounds, changes in driving and performance, or warning lights lit up on the dashboard, do not ignore them. These are often early signs of an issue that should be addressed ASAP before they escalate into larger problems later on. Consult with a mechanic locally or online about these problems and get advice on if they require attention.

When to Ask a Mercedes Mechanic Online

If your schedule is packed, or you gave fixing the no start yourself an honest effort but with no luck, consider consulting a Mercedes mechanic online. It delivers expert guidance in just minutes from the comfort of home, and is far less expensive than a tow and diagnosis at the local garage.

Advantages of an Online Mercedes Mechanic

Happy mechanic repairing car looking at camera

By detailing what you’ve already tried and sharing specifics on the no-start issue, online mechanics can then offer a custom action plan to help get your car started again. With so many Mercedes mechanics available they can help fix nearly any problem, it doesn’t if matter it’s your W124 that’s having issues or a Mercedes Vito won’t start, the online mechanics can help sort anything in no time. And with many household budgets tighter these days, the convenience and affordability of online mechanics help, keep your wallet happy too.

You can describe the issues you’re having, ask Mercedes mechanics unlimited questions, and even submit pics and videos so you can show the mechanic what you mean. You can connect with them via instant messenger or voice chat, whatever you like. The Mercedes mechanic will ID the problem, recommend the best fix for your specific situation, and even guide you on basic repairs step-by-step.

Whether you want an expert second opinion or are simply short on time, online repairs assistance is there when you need it. Give it a try to see firsthand how convenient fixing problems can be.

So feel free to try out our Mercedes repair questions service and see for yourself!

When and How to Get a Local Mercedes Mechanics Help

automobile mobile mechanic

When your Mercedes W124 won’t start, and you are unable to repair it yourself, thinking about how to get your vehicle to the garage can be a nightmare. There are options like roadside services, that come to you and can provide simple fixes to get your car moving enough again, so you can get it to a mechanic garage for proper repairs. You can also use a towing service, but these can be costly, easily into the hundreds of dollars. A much better option is the use of a mobile mechanic, who will come to you at your home, place of work, or by the roadside, and carry out repairs there and then for you, so you can get your W124 started again ASAP.

So if you think a mobile mechanic is the best solution for you, instead of searching on Google something like  “home mechanic near me“, the best in the USA that also covers most towns is YourMechanicI have personally recommended them to countless people across the country and they always have a great experience.

Reasons I recommend them:

  • They use experienced ASE-certified mechanics
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  • Low Cost compared to regular garages

If you would like to know more, the process to use them is this.

  1. Visit their official website here: YourMechanic
  2. Get an instant free quote for what you need
  3. Book a time and place for the mechanic to come to you
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Super easy, super reliable, super convenient, and highly recommended.

Conclusion

In short, when your Mercedes W124 doesn’t turn over, it can be a major inconvenience. However, understanding what might be causing the issues, being able to diagnose them, and knowing what actions are required in each case, and where to find help if needed, will be a huge help. Keep in mind that regular maintenance is vital to preventing most car issues.

Frequently Asked Questions (FAQs) When a Mercedes W124 Won’t Start

Mercedes W124 won’t start but lights turn on?

If your Mercedes W124‘s lights illuminate but it still won’t start, the issue may not be related to the battery. It’s highly possible there is a problem with the starter motor. Investigate if you hear any clicking sounds when attempting to crank the key. If so, the starter motor is attempting to activate but failing. Get a mechanic inspect the starter motor – it may need to be repaired or replaced.

Mercedes W124 won’t start but has power?

When your Mercedes W124 has power (lights, radio etc work) but does not start up, there may be a fuel delivery problem. Issues like a faulty fuel pump relay could stop fuel getting to the engine. Without enough fuel, combustion can’t happen and the engine won’t start. Listen near the back seat when cranking the key – you should hear the fuel pump prime for a few seconds. If not, have a mechanic check the fuel system.

Mercedes W124 won’t start but battery is fine?

If your Mercedes W124‘s battery checks out OK and is fully charged, but the car still refuses to start, the underlying cause is likely electrical. Possible issues include a bad ignition switch, broken sensor, or wiring problems. As electrical issues can be tricky, diagnosis by a professional mechanic is best. They can correctly pinpoint the specific electrical fault and have it repaired.

Mercedes W124 won’t start just clicking?

When you turn the key and just hear clicking but the engine doesn’t crank, the most common cause is a faulty starter motor. The click comes from the starter solenoid attempting to activate the starter motor, but the motor itself fails to spin up the engine. As the starter motor needs physical fixing or swapping out, consult with a reliable mechanic to get your Mercedes W124 running again.

What if my Mercedes W124 won’t start up?

First things first, take a deep breath and don’t panic. Look for any odd noises, flashing lights, or changes in how it runs that could point to the issue. Most likely the culprit is one of the common problems we will talk about here. If you still can’t identify the exact issue, you’ll have to consult a trusted Mercedes mechanic locally or online.

How do I know if my Mercedes W124 won’t start because of the battery?

Signs that your Mercedes’s battery is the issue include, a slow cranking engine, dim headlights, and battery warning symbols lighting up on the dash. You can also check that the battery terminals are clean, corrosion-free, and tightly fastened. If your battery is older it’s probably best to just replace it completely.

How to prevent my Mercedes W124 from failing to start in the future?

To prevent this frustration from repeating, regular upkeep is vital. This includes oil changes, inspecting the battery and scrubbing its terminals, replacing the fuel filter when necessary, and getting your Mercedes W124 evaluated by a mechanic routinely. Also, be diligent about drive the car regularly so the battery stays charged.

Can I consult an online mechanic if my Mercedes W124 fails to start up?

Yes, you can. An online mechanic service like ours can offer instant expert Mercedes mechanic aid and suggestions, without you having to leave your residence. If your vehicle fails to start and is stuck in the driveway, this is particularly beneficial.

In what ways can websites like MechanicAnswer.com lend a hand if my Mercedes W124 isn’t starting?

We link you with certified Mercedes technicians who can offer recommendations particular to your exact situation. You can update them about your auto problems, ask unlimited questions as needed, and even submit videos or pictures so you can comprehensively demonstrate the problem. The mechanic will be capable to aid, diagnose the problem, and recommend the best solution and talk you through it.

Interesting Mercedes W124 Facts

Did you know that the Mercedes W124 was the first car to have a passenger airbag as a standard feature? That’s right, this iconic vehicle was ahead of its time when it came to safety features. Not only that, but the W124 also had a self-leveling suspension system, making it one of the most comfortable rides on the road. And get this – the W124 was so well-built that it’s not uncommon to find models with over 500,000 miles on the odometer and still running strong. Talk about durability! Plus, with its timeless design and luxurious interior, it’s no wonder the W124 has a cult following to this day. So if you’re having trouble getting your W124 started, just remember all the amazing features that make it such a special car, and you’ll be back on the road in no time!

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Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just £5.
  2. Get help from a Mobile Mechanic. We  recommend Fixter. They will come to you and fix your vehicle at a time that suits you. Instant free quote online below. We recommend the online mechanic first, as it’s cheaper for you, and you may not need an in-person mechanic.

Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just $5.
  2. Get in-person help from a Mobile Mechanic. We recommend YourMechanic. They will come to you and fix your vehicle at a time that suits you. Instant free quote online below. We recommend the online mechanic first, as it’s cheaper, and you may not need an in-person mechanic.

Choose Your Mechanic

1. Chat with A.I. Mechanic (Robot Robby)
  • Free 7-day trial
  • A.I. Mechanic that is trained by our human mechanic writers. As helpful as a human mechanic for expert advice, troubleshooting, and repair guidance.
2. Chat with a Human Mechanic Online
  • Join for just $5, and $39/month. Cancel anytime
  • Real human ASE-certified mechanics available 24/7

Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just $5.
  2. Get in-person help from a Mobile Mechanic Near You. They will come to you and fix your vehicle at a time that suits you. If there are none near you, you will be redirected to the online mechanic.

Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just £5.
  2. Get help from a Mobile Mechanic. We  recommend Fixter. They will come to you and fix your vehicle at a time that suits you. Instant free quote online below. We recommend the online mechanic first, as it’s cheaper for you, and you may not need an in-person mechanic.

Which Mechanic Suits You?

  1. Chat with an Online Mechanic to get instant, unlimited help and advice for 1 full week, for just $5.
  2. Get in-person help from a Mobile Mechanic. We recommend YourMechanic. They will come to you and fix your vehicle at a time that suits you. Instant free quote online below. We recommend the online mechanic first, as it’s cheaper, and you may not need an in-person mechanic.

Where Can I Find My VIN?

Your vehicle’s unique Vehicle Identification Number (VIN) can be found on the title document, the vehicle registration, and the insurance policy. It is a series letters and numbers like this as example: WAUGC0896JA235262. The VIN can also be located on the following locations on the vehicle itself:

how to find VIN on vehicle