Why does my 840i’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. It’s just your 840i firing up its circuits. The light should turn off in a bit, but come see us if it doesn't.

Why is my BMW 840i making engine noise?

Strange engine sounds can be a sign something’s off in your BMW 840i. Knocking or tapping could be a symptom of low oil. 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 BMW engine? [ordered-list-1-item-3-1]Are you unknowingly damaging your BMW 840i engine?

Certain driving habits can damage your engine and should be avoided. These habits include 'running on fumes,' flooring the gas pedal while the car is in Park, or accelerating too quickly, too soon. Protect your engine’s performance and efficiency by distancing yourself from these habits.

Is it okay to put water in my BMW 840i radiator?

While it’s not recommended, you can use water in your 840i radiator in emergencies. Normally, you should only use a 50/50 mix of coolant and water or a pre-mixed coolant. However, if you are completely out of coolant and must continue driving, it’s better to have water in your coolant reservoir than nothing.

What can cause a 840i engine to suddenly stop?

If your 840i car engine suddenly stops, it could be due to overheating, low fuel, a faulty ignition system, sensor problems, electrical system trouble, or mechanical issues.

Who fixes BMW 840i engines?

For BMW 840i engine repair, trust your local Firestone Complete Auto Care. You can make an appointment today at any of our thousands of locations across the U.S.

Engine Repairs for Your 2025 BMW 840i

Learn about

2025 BMW 840i Trim Options

Select your BMW 840i trim level to learn more about BMW-recommended engine repair. Use the following chart to find information.

BMW 840i Repairs and Services

Nothing stays the same forever. Even your BMW 840i's many parts and pieces. When something breaks or fails, we’re ready to help. Select a repair or category to learn more about 2025 BMW 840i services.

We Care for BMW 840i Engines

BMW 840i engines are known for their reliability. You may have even been thinking about that when you bought it. Even so, pieces and parts can break down over time. Things can go sideways sometimes. When they do, you might find yourself searching for 2025 BMW 840i engine repair or replacement parts. That's when it's time to head to Firestone Complete Auto Care. We've serviced more than 500 million vehicles since 1926, and our technicians know BMW 840i engines. Schedule an appointment if you're experiencing problems that could require engine repair. Firestone Complete Auto Care offers both trustworthy and affordable engine repairs.

Illuminated Check Engine Light on 2025 BMW 840i

If your 840i check engine light is on, it’s time to get it looked at. A check engine light that’s flashing or steadily illuminated could point to problems with your or emission control system that won’t go away on its own. Possible causes can include a failing oxygen sensor, bad spark plug, a clogged catalytic converter, or an engine vacuum leak, to name a few possible causes. Bring your 840i in for an on-board diagnostic check and we'll determine exactly why your check engine light is on. rattling sounds, oil leaks, or a sinking feeling that something’s wrong.

BMW 840i Engine Repair

If your 2025 840i engine needs repairs, our technicians will provide you with a thorough explanation beforehand. We never do any work without your sign-off. If a service can wait, we’ll make sure you know. But if immediate repairs are necessary for your safety, we’ll make sure that's clear, too. We want to provide you with the information you need to make an informed engine repair decision. By choosing Firestone Complete Auto Care for 840i engine repairs and you can drive easy knowing that we use BMW-approved parts and fluids — cambelt, engine oil seal, fuses, or other parts.

Questions About 2025 BMW 840i Engines

Why does my 840i’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. It’s just your 840i firing up its circuits. The light should turn off in a bit, but come see us if it doesn't.
Why is my BMW 840i making engine noise? Strange engine sounds can be a sign something’s off in your BMW 840i. Knocking or tapping could be a symptom of low oil. 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 BMW engine? [ordered-list-1-item-3-1]Are you unknowingly damaging your BMW 840i engine? Certain driving habits can damage your engine and should be avoided. These habits include 'running on fumes,' flooring the gas pedal while the car is in Park, or accelerating too quickly, too soon. Protect your engine’s performance and efficiency by distancing yourself from these habits.
Is it okay to put water in my BMW 840i radiator? While it’s not recommended, you can use water in your 840i radiator in emergencies. Normally, you should only use a 50/50 mix of coolant and water or a pre-mixed coolant. However, if you are completely out of coolant and must continue driving, it’s better to have water in your coolant reservoir than nothing.
What can cause a 840i engine to suddenly stop? If your 840i car engine suddenly stops, it could be due to overheating, low fuel, a faulty ignition system, sensor problems, electrical system trouble, or mechanical issues.
Who fixes BMW 840i engines? For BMW 840i engine repair, trust your local Firestone Complete Auto Care. You can make an appointment today at any of our thousands of locations across the U.S.