Why does my 350SD’s check engine light come on when I start it?

It's okay if your check engine light comes on when you first start your vehicle. This is a sign that your vehicle is testing its circuits. The light should go off shortly. Bring your vehicle in if it doesn't.

Why is my Mercedes-Benz 350SD making engine noise?

Strange under-the-hood noises can point to problems within your Mercedes-Benz 350SD engine. Tapping or knocking could mean you need an oil change. Whistling sounds could mean you have an intake leak or misaligned belt. Squealing can be traced back to a loose fan belt, and grinding could be a sign that something is wrong with your brakes — not the engine.

What could damage a Mercedes-Benz engine? [ordered-list-1-item-3-1]Are you unknowingly damaging your Mercedes-Benz 350SD engine?

Some driving habits are not so great for your engine. These include driving on a near-empty gas tank, revving your engine while the vehicle is in Park, or slamming the gas pedal while the engine is still cold. Steer clear of these habits to help protect engine performance and efficiency.

Can I add water to my Mercedes-Benz 350SD radiator?

An emergency is the only time you should consider putting water in your radiator. Outside of that, it’s recommended you use a pre-mixed coolant or a 50/50 blend of water and coolant. However, if you need to continue driving your 350SD when you’re out of coolant, having water in the coolant reservoir is better than nothing.

Why did my 350SD engine suddenly stop?

Your 350SD car engine could stop suddenly due to low fuel, electrical issues, overheating, a faulty ignition system, mechanical troubles, or sensor problems.

Where can I go for Mercedes-Benz 350SD repair?

Your local Firestone Complete Auto Care offers Mercedes-Benz 350SD engine repair. Schedule an appointment today at one of our thousands of locations nationwide!

Engine Repairs for Your 1991 Mercedes-Benz 350SD

Learn about

1991 Mercedes-Benz 350SD Trim Options

Select your Mercedes-Benz 350SD trim level to learn more about Mercedes-Benz-recommended engine repair. Use the following chart to find information.

L6/3.4L

Repairs for Your 1991 Mercedes-Benz 350SD

Stuff wears out. Even your Mercedes-Benz 350SD’s engine parts and components will change. We’re here to help when something stops working. Select a service or repair below to learn more about what we can do for your 1991 Mercedes-Benz 350SD.

We Know Mercedes-Benz 350SD Engines

Mercedes-Benz 350SD drivers trust that their 350SD will take them near and far. You may have even been thinking about that when you bought it. However, even your trustworthy engine is subject to wear and tear. Things can go sideways sometimes. If they do, you’ll have to find a dependable 1991 Mercedes-Benz service center — quick! Luckily, you won’t have to look far, since Firestone Complete Auto Care has 1,700+ locations across the country. We've serviced millions of vehicles since 1926, and our professional technicians are trained to service Mercedes-Benz 350SD engines. Schedule an appointment if you're experiencing problems that could require engine repair. After all, Firestone Complete Auto Care is one of the most popular picks for professional engine repairs thanks to its service and affordability.

Illuminated Check Engine Light on 1991 Mercedes-Benz 350SD

An illuminated check engine light on your Mercedes-Benz 350SD is one of the first signs it's time to 'brake' for engine service. A check engine light that’s on or flashing could be a symptom of a serious problem in your fuel injection, Possible causes can include a failing oxygen sensor, worn spark plug, issues with your catalytic converter, or an engine vacuum leak, to name a few potential sources. Bring your 350SD to Firestone Complete Auto Care to get computerized diagnostics and we'll determine exactly why your check engine light is on. Other signs your Mercedes-Benz 350SD engine needs some TLC are oil leaks, or misfiring.

Mercedes-Benz 350SD Engine Repair

If your 1991 Mercedes-Benz 350SD needs engine repair, our technicians will provide you with a thorough explanation beforehand. We make recommendations, but you make the final decision. If a repair can wait, we'll let you know. But if immediate repairs are necessary for your safety, we’ll make sure that's clear, too. We want to give you all the details you need to make an informed decision about your engine repairs. Turn to Firestone Complete Auto Care for your 1991 350SD engine repairs and you can drive easy knowing that we use Mercedes-Benz-approved parts and fluids — serpentine belt, motor oil seal, sensors, or another part.

Questions About 1991 Mercedes-Benz 350SD Engines

Why does my 350SD’s check engine light come on when I start it? It's okay if your check engine light comes on when you first start your vehicle. This is a sign that your vehicle is testing its circuits. The light should go off shortly. Bring your vehicle in if it doesn't.
Why is my Mercedes-Benz 350SD making engine noise? Strange under-the-hood noises can point to problems within your Mercedes-Benz 350SD engine. Tapping or knocking could mean you need an oil change. Whistling sounds could mean you have an intake leak or misaligned belt. Squealing can be traced back to a loose fan belt, and grinding could be a sign that something is wrong with your brakes — not the engine.
What could damage a Mercedes-Benz engine? [ordered-list-1-item-3-1]Are you unknowingly damaging your Mercedes-Benz 350SD engine? Some driving habits are not so great for your engine. These include driving on a near-empty gas tank, revving your engine while the vehicle is in Park, or slamming the gas pedal while the engine is still cold. Steer clear of these habits to help protect engine performance and efficiency.
Can I add water to my Mercedes-Benz 350SD radiator? An emergency is the only time you should consider putting water in your radiator. Outside of that, it’s recommended you use a pre-mixed coolant or a 50/50 blend of water and coolant. However, if you need to continue driving your 350SD when you’re out of coolant, having water in the coolant reservoir is better than nothing.
Why did my 350SD engine suddenly stop? Your 350SD car engine could stop suddenly due to low fuel, electrical issues, overheating, a faulty ignition system, mechanical troubles, or sensor problems.
Where can I go for Mercedes-Benz 350SD repair? Your local Firestone Complete Auto Care offers Mercedes-Benz 350SD engine repair. Schedule an appointment today at one of our thousands of locations nationwide!