Bojan Popic

Bojan Popic

Mechanical Engineer & Automotive Technician

Bojan Popic is a mechanical engineer and long-time automotive technician who creates and edits much of the visual and written content on Mechanic Base. His engineering background helps him explain complex vehicle systems in a simple, step-by-step way that anyone can follow.

Bojan has more than ten years of experience working with diagnostics, maintenance and component testing. He focuses on turning technical information into clear, practical guides that help readers understand how their cars actually work.

At Mechanic Base, Bojan produces detailed repair videos and collaborates on article editing to keep every post accurate, up to date and easy to understand.

Expertise and Certifications

  • Mechanical Engineer (B.Sc.)
  • Over ten years of practical automotive repair experience
  • Diagnostic process design and testing
  • Video production and technical editing

Areas of Focus

  • Educational repair videos
  • Vehicle system diagnostics
  • Step-by-step maintenance procedures
  • Editing and accuracy review of technical content

Featured Work by Bojan

Follow Bojan

Watch Bojan’s diagnostic walkthroughs on the Mechanic Base YouTube channel or explore his latest repair tutorials here on the site.

Bojans Latest Videos

These 12 bad driving habits are slowly destroying your car — and most drivers don’t even realize they’re doing them. In this video, I break down the most common habits that cause expensive repairs, engine damage, and unnecessary wear on your vehicle. If you want your car to last longer, run smoother, and avoid costly trips to the mechanic, this guide is for you. You’ll learn: 🚫 Habits that ruin your engine 🚫 Mistakes that damage your transmission 🚫 What kills your brakes and suspension 🚫 Daily driving habits that wear out the turbo 🚫 How idling harms your engine 🚫 Things you should never do when the engine is cold 🚫 Gas-saving myths that actually damage your car Most of these habits affect everyday cars like Toyota, Honda, Ford, Chevy, Nissan, Jeep, and Hyundai — and fixing them can save you hundreds or even thousands in repairs. #BadDrivingHabits #CarMaintenance #CarTips
12 BAD Habbits that DESTROY Your Car
How to change engine oil safely and correctly — even if you’ve never done it before! In this video, I’ll show you the full step-by-step process for changing your engine oil and oil filter at home. This method works for almost any car, and it can save you a lot of money compared to going to a repair shop. You’ll learn: ✅00:00 – Intro - how to change engine oil at home? ✅01:05 – Tools you’ll need & How to choose the right oil ✅02:45 – Draining old oil ✅04:25 – Oil filter replacement ✅05:30 – Installing drain plug (torque tips) ✅06:10 – Adding new engine oil ✅06:45 – Checking oil levels ✅07:45 – Final tips Whether you drive a Toyota, Honda, Ford, Chevy, Nissan, or Jeep, this guide applies to most vehicles sold in the US. #EngineOilChange #CarMaintenance #DIYCarRepair
How to Change Engine Oil (Step-By-Step Tutorial for Beginners)
Learn how to perform an easy DIY oxygen sensor test at home with this step-by-step guide. Testing your oxygen sensor can help you identify issues with your vehicle's engine and improve its overall performance. By following the simple steps outlined in this video, you can save time and money by avoiding a trip to the mechanic. The oxygen sensor plays a crucial role in maintaining the right air-fuel mixture, and a faulty sensor can lead to decreased fuel efficiency, poor engine performance, and increased emissions. With the right tools and a bit of knowledge, you can test your oxygen sensor yourself and get back on the road in no time. Whether you're a seasoned DIY enthusiast or just starting out, this video will walk you through the process and provide you with the confidence to take on the task. So, watch now and learn how to test your oxygen sensor at home with ease. What you’ll learn in this video: 00:00 Intro - testing the Oxygen Sensor 00:32 Check the O2 sensor with OBD scanner 03:25 Testing the O2 sensor with a multimeter 04:05 Check the wiring 04:40 Oxygen Sensor Location 06:37 How to clean the oxygen sensor
How to Test an Oxygen Sensor (O2) Easy DIY Guide
Is your car emitting blue smoke from the exhaust? This can be a sign of a serious issue, such as engine burning oil, which can lead to costly repairs if left unchecked. In this video, we will explore the common causes of blue smoke from the exhaust, including worn piston rings, bad valve seals, and turbo smoking, as well as pcv valve problems. We will also discuss the symptoms of oil burning, such as oil in the exhaust, and how to diagnose the issue. Additionally, we will provide tips on how to fix the problem, including the potential blue smoke repair cost. If you're experiencing car problems, such as blue exhaust smoke, it's essential to address the issue promptly to avoid further damage to your vehicle. Regular car maintenance and automotive repair can help prevent issues like blue smoke from the exhaust, so be sure to check out our channel, mechanicbase, for more information on car repair and engine diagnostics. By understanding the causes and symptoms of blue smoke from the exhaust, you can take steps to fix the problem and get back on the road. WEBSITE: https://mechanicbase.com/ Inquiries: https://mechanicbase.com/contact-us/ Facebook: https://www.facebook.com/mechanicbase/ What you’ll learn in this video: 00:00 Intro – Why blue smoke happens 00:40 Blue smoke from exhaust causes 05:13 When to keep driving and when to stop 06:45 Repair costs and what to expect #BlueSmoke #ExhaustSmoke #EngineProblems
Blue Smoke From Exhaust? Causes & How to Fix it
Engine noises, rough idling, and hard starting can often be linked to the symptoms of a bad timing belt, especially when the belt begins to stretch, wear, or lose tension. In this video, we walk you through the early warning signs of timing belt problems and explain what happens as the belt begins to fail. You’ll learn how the timing belt keeps the crankshaft and camshaft synchronized, why even slight wear can affect performance, and how catching issues early can help you avoid catastrophic engine damage. In a separate section, we look more closely at bad timing belt symptoms so you can recognize misfires, oil-soaked belts, unusual ticking noises, poor acceleration, and rough running before these issues turn into major failures. We also explain why some engines suffer bent valves or damaged pistons when the timing belt slips or breaks, and how to tell the difference between normal wear and warning signs that require immediate attention. We also break down the timing belt replacement cost, covering what affects the price and why this job is often more expensive than it seems. Since many vehicles require replacing the water pump, tensioners, and pulleys at the same time, we explain what to expect and how to plan for the full service. What you’ll learn in this video: 00:00 Intro 00:47 Bad Timing Belt Symptoms 03:29 Wet Timing Belts (Belt in Oil) 04:23 Timing Belt Replacement Schedule 05:01 What a Timing Belt Does 06:25 Timing Belt Location 07:19 Timing Belt Replacement Cost 08:35 What Happens If the Timing Belt Breaks WEBSITE: https://mechanicbase.com/ Inquiries: https://mechanicbase.com/contact-us/ Facebook: https://www.facebook.com/mechanicbase/ Common searches related to this topic include: bad timing belt symptoms symptoms of a bad timing belt timing belt failure symptoms timing belt noise timing belt in oil timing belt replacement cost signs of a worn timing belt timing belt diagnosis when to replace timing belt what happens if timing belt breaks Learn how to recognize timing belt warning signs early and understand the true cost of replacement before serious engine damage occurs. Mechanic Base gives you clear, trustworthy guidance on car diagnostics, repairs, and maintenance. Whether you're tracking down engine issues, fixing electrical faults, or handling routine service, we make every repair easier to understand and more affordable. #TimingBelt #EngineTiming #AutoRepair
Symptoms Of A Bad Timing Belt (and Replacement Cost)
Cleaning your engine bay can feel intimidating, but with the right method, it’s completely safe and a great way to keep your vehicle in top condition. In this video, we walk you through how to wash your car’s engine safely without risking electrical damage, corrosion, or sensor problems. You’ll learn which components must be protected before spraying anything, how to choose the best engine degreaser, and the correct tools to use so you remove grease and grime without harming delicate connectors. This step-by-step guide gives you the confidence to clean under the hood just like a professional detailer. We also explain the safest way to rinse your engine bay, how much water is actually needed, and how to avoid high-pressure spray that can force moisture into wiring or ignition components. Whether your engine is lightly dusty or covered in years of built-up oil and dirt, these techniques work on nearly all modern vehicles, including Ford, Chevy, Dodge, Toyota, Honda, and more. You’ll also learn how to dry the engine properly, prevent water spots, and finish the job with simple detailing tips that restore a fresh, factory-clean look. This tutorial is perfect for anyone who wants to improve appearance, prevent corrosion, and make future maintenance easier without putting the car at risk. With a little preparation and the right method, washing your engine bay is completely safe and surprisingly easy. WEBSITE: https://mechanicbase.com/ Inquiries: https://mechanicbase.com/contact-us/ Facebook: https://www.facebook.com/mechanicbase/ What you’ll learn in this video: 00:00 Intro 00:45 What to protect before washing 02:30 Best engine degreaser and tools 04:00 How to safely rinse the engine bay 05:45 Drying and finishing touches 07:00 Engine bay detailing tips Common searches related to this topic include: how to wash engine safely how to clean engine bay engine bay cleaning wash car engine without damage degrease engine bay safe engine cleaning how to cover engine before washing engine bay detailing guide cleaning engine components is it safe to wash your engine Learn how to safely clean your engine bay, avoid electrical damage, and make your car look like new. Mechanic Base gives you clear, trustworthy guidance on car diagnostics, repairs, and maintenance. Whether you're tracking down engine issues, fixing electrical faults, or handling routine service, we make every repair easier to understand and more affordable. #EngineCleaning #CarDetailing #CarMaintenance
How to Safely Wash Your Engine (DIY Step-by-Step Guide)
If your engine is running rough, idling unevenly, or showing an EGR-related Check Engine Light, properly testing the EGR valve is one of the most important steps before replacing anything. In this video, we walk you through exactly how to test an EGR valve using both a vacuum pump and a diagnostic scanner so you can determine whether the valve is functioning correctly. You’ll learn how the EGR system regulates exhaust gas flow, how the valve interacts with the intake, and why a stuck or restricted EGR valve can cause hesitation, poor acceleration, or increased emissions. These tests work on most Ford, Chevy, Dodge, Toyota, Honda, and diesel engines. We also go through the most common EGR valve trouble codes and explain what each one means in real-world conditions. Whether the code indicates low flow, excessive flow, or circuit malfunction, we break down how to interpret the data and confirm the root cause. You’ll learn how to check the valve movement with a vacuum pump, how to read live data with a scan tool, and how to verify that the passages and hoses connected to the EGR system are not blocked. To help with planning your repair, we also outline the typical EGR valve repair cost, including what affects the price and when cleaning the valve may be a more affordable option. This gives you a clear idea of what to expect before visiting a shop or attempting the repair yourself. WEBSITE: https://mechanicbase.com/ Inquiries: https://mechanicbase.com/contact-us/ Facebook: https://www.facebook.com/mechanicbase/ What you’ll learn in this video: 00:00 Intro 01:13 Typical EGR valve trouble codes 02:27 How to test EGR valve with vacuum pump? 03:30 How to test EGR valve with a diagnostic tool? 05:00 Symptoms of a bad EGR valve 06:30 How the EGR valve works? 07:30 Repair costs and final tips Common searches related to this topic include: how to test an egr valve egr valve test bad egr valve symptoms egr valve diagnosis how to check egr valve egr valve vacuum test egr trouble codes rough idle egr valve egr system problems egr valve repair cost Learn how to diagnose EGR valve issues, confirm common symptoms, and avoid unnecessary parts replacement. Mechanic Base gives you clear, trustworthy guidance on car diagnostics, repairs, and maintenance. Whether you're tracking down engine issues, fixing electrical faults, or handling routine service, we make every repair easier to understand and more affordable. #EGRValveTest #EGRValve #CarDIY
How to Test an EGR Valve (DIY Guide)
A loud ticking or tapping noise under the valve cover can be alarming, and noisy valve lifters are one of the most common causes of engine tick. In this video, we break down why lifters become noisy, what happens inside the valvetrain when oil flow is restricted, and how you can fix lifter tick without immediately replacing parts. You’ll learn how cold starts, low oil level, poor oil quality, sludge buildup, and worn components affect lifter movement and why hydraulic lifters are especially sensitive to changes in oil pressure and viscosity. These steps apply to most engines, whether you drive a Chevy, Ford, Dodge, Toyota, Honda, or similar modern vehicle. We also walk you through practical solutions to quiet noisy lifters safely. From choosing the right engine oil and using additives to flushing the oil system and checking for low oil pressure, the video shows what to try first before considering major repairs. Understanding how valve lifters work, how they receive oil through the valvetrain, and the signs of restricted flow will help you diagnose the issue more confidently and avoid long-term damage caused by insufficient lubrication. To help you plan ahead, we include a clear overview of the valve lifter replacement cost. Because labor time varies widely depending on engine design, this section explains what influences pricing, when lifter replacement is necessary, and when cleaning or improving oil flow is enough to restore quiet operation. WEBSITE: https://mechanicbase.com/ Inquiries: https://mechanicbase.com/contact-us/ Facebook: https://www.facebook.com/mechanicbase/ What you’ll learn in this video: 00:00 Intro - What causes noisy lifters 00:46 Check Oil Level 01:21 Use Different Engine Oil 01:53 Flush Engine Oil 02:47 Use Valve Lifter Additive 03:39 Check Oil Pressure 05:31 How Valve Lifters Work 06:30 Valve Lifter Replacement Cost Common searches related to this topic include: noisy valve lifters valve lifter tick fix lifter ticking noise how to quiet lifter noise engine ticking at idle hydraulic lifter noise lifter noise on startup valve lifter cleaning lifter tick causes low oil pressure lifter noise Learn how to diagnose noisy valve lifters, reduce engine ticking, and prevent long-term damage. Mechanic Base gives you clear, trustworthy guidance on car diagnostics, repairs, and maintenance. Whether you're tracking down engine issues, fixing electrical faults, or handling routine service, we make every repair easier to understand and more affordable. #ValveLifters #EngineNoise #AutoRepair
Noisy Valve Lifters? Common Causes & How to Fix it
A faulty MAF (Mass Air Flow) sensor can cause a wide range of drivability issues, but before replacing it, the most important step is proper testing. In this video, we show you exactly how to test a MAF sensor using both an OBD2 scanner and a multimeter so you can confirm whether the sensor is actually bad. You’ll learn what normal MAF readings should look like, how the sensor measures incoming air, and why incorrect airflow data leads to rough running, hesitation, poor fuel economy, or even stalling. These procedures work on most vehicles including Ford, Chevy, Toyota, Honda, Nissan, BMW, and many others. We also walk you through the most common MAF sensor trouble codes, how to interpret the scanner data, and what patterns often indicate a failing sensor. If your car is idling roughly, stumbling under acceleration, or showing inconsistent airflow readings, these diagnostic steps will help you determine whether the MAF sensor, wiring, or another component is responsible. You’ll also learn how to check voltage signals with a multimeter, verify sensor responsiveness, and ensure your engine is getting accurate air-flow information. To help restore performance, we also cover how to clean a MAF sensor safely, which cleaners work best, and which mistakes to avoid. Cleaning can often fix contamination issues and bring the sensor back to normal operation without replacing it. WEBSITE: https://mechanicbase.com/ Inquiries: https://mechanicbase.com/contact-us/ Facebook: https://www.facebook.com/mechanicbase/ What you’ll learn in this video: 00:00 Intro 00:40 MAF sensor codes 01:45 Testing with OBD2 scanner 05:10 Testing with a multimeter 06:45 Cleaning the MAF sensor Common searches related to this topic include: bad maf sensor symptoms how to test maf sensor maf sensor multimeter test maf sensor obd2 readings signs of a bad maf sensor maf sensor voltage test cleaning maf sensor maf sensor diagnosis rough idle maf sensor maf trouble codes Learn how to test your MAF sensor accurately and avoid misdiagnosing other engine components. Mechanic Base gives you clear, trustworthy guidance on car diagnostics, repairs, and maintenance. Whether you're tracking down engine issues, fixing electrical faults, or handling routine service, we make every repair easier to understand and more affordable. #MAFSensor #MAFTest #CarDiagnostics
Bad MAF Sensor? How to Test with Multimeter or OBD2
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