Car Repair Myths and Bad Advice That Can Cost You Big

When something goes wrong with your vehicle, it's tempting to turn to a friend, a YouTube video, or a random online forum. But not all car advice is created equal — and following the wrong suggestion can do serious damage to your vehicle or even put you in danger.

At Harrell & Beverly Transmissions & Auto Repair, we’ve seen some wild recommendations over the years. Here are just a few examples of what not to do, and the safer, smarter alternatives.

Examples of Bad Car Repair Advice

1. “Touch the Battery Cables Together to Reprogram the Transmission”

We recently had a customer with a Chrysler 300 that wouldn’t accelerate beyond 40 mph. Someone told him to disconnect the positive battery terminal and touch it to the negative post to reset the transmission. This was a dangerous suggestion and we're glad they brought the vehicle to us!

🚫 Why it’s bad advice: Touching the positive and negative terminals can cause a short circuit, spark a fire, or even make the battery explode.

✅ What you should do instead: Bring the car in for proper testing and evaluation. Transmission issues need to be diagnosed with professional equipment and procedures — not sparks.

2. “Just Unplug the Check Engine Light”

Some people think that if the light is annoying, it’s okay to just disable it.

🚫 Why it’s bad advice: That light is a warning system for a reason. Disabling it doesn’t fix the problem — it hides it, potentially allowing major damage to go unnoticed.

✅ What you should do instead: Have the vehicle properly tested. At Harrell & Beverly, we use advanced tools and experienced technicians to interpret what the light means and determine the real issue.

3. “Add a Bottle of Transmission Fluid Conditioner and You’ll Be Fine”

Some quick-fix products claim they can solve transmission slipping or rough shifts.

🚫 Why it’s bad advice: Additives may temporarily mask symptoms, but they don’t fix internal transmission problems. In some cases, they can even make things worse by altering fluid properties.

✅ What you should do instead: If your transmission is acting up, have it evaluated by a shop that specializes in drivetrain systems (like us!). Catching issues early can help you avoid a full rebuild.

4. “You Don’t Need to Change Transmission Fluid, It’s Lifetime Fluid”

This myth often comes straight from the manufacturer’s marketing materials.

🚫 Why it’s bad advice: “Lifetime fluid” doesn’t mean forever. Over time, even sealed transmission fluid breaks down and collects debris. Waiting too long can cause internal damage.

✅ What you should do instead: We recommend a fluid exchange at regular intervals — and we use OEM-compliant equipment and fluid to ensure long-term performance. Check with your preferred mechanic on your vehicle's recommended intervals.

5. “If It Ain’t Broke, Don’t Fix It” (Especially for Brakes, Fluids, and Filters)

Delaying maintenance to save money now often leads to bigger expenses later.

🚫 Why it’s bad advice: Waiting until something fails can leave you stranded or cause collateral damage to other components.

✅ What you should do instead: Follow your maintenance schedule and get regular inspections. Preventative care is always cheaper than a tow truck and a major repair bill.

6. “Bleed the Brakes by Pumping Them With the Engine Running”

🚫 Why it’s bad advice: This can introduce air into the ABS system and damage the brake booster or master cylinder.

✅ What to do instead: Brake systems should be bled following the proper sequence — often with the help of a scan tool for modern ABS systems. Leave this one to the pros.

7. “Tighten the Lug Nuts As Much As You Can With a Pipe”

🚫 Why it’s bad advice: Over-tightening can warp brake rotors, strip threads, or break wheel studs. It also makes removal difficult in emergencies.

✅ What to do instead: Always use a torque wrench and follow manufacturer specifications. We torque every wheel to spec here at Harrell & Beverly.

8. “WD-40 Will Fix That Squeaky Belt”

🚫 Why it’s bad advice: WD-40 is a water-displacing lubricant, not a belt conditioner. It can damage rubber and attract dirt, leading to faster wear or even slippage.

✅ What to do instead: Check the belt and tensioner for wear. If it’s squeaking, it probably needs to be replaced — not sprayed.

9. “Don’t Worry About Oil Changes if the Car Still Runs Fine”

🚫 Why it’s bad advice: Modern engines run tighter tolerances and depend heavily on clean oil. Skipping oil changes leads to sludge buildup and engine failure.

✅ What to do instead: Follow the oil change interval for your driving habits and environment — and always use the correct oil grade.

10. “Just Disconnect the Battery to Fix Electrical Issues”

🚫 Why it’s bad advice: Disconnecting the battery won’t fix a sensor fault or module issue, and may even erase trouble codes that are useful for diagnostics.

✅ What to do instead: Have the system properly scanned by a pro. It’s better to fix the real issue than wipe away clues.

Final Thoughts: Real Car Help, Not Myths

There’s no shortage of car tips floating around the internet and backyard garages, but not all of them are safe — or even remotely accurate. When it comes to your vehicle, sticking with professional testing, timely maintenance, and trusted repair processes will always be the smarter choice.

At Harrell & Beverly Transmissions & Auto Repair in Sanford, we don’t just fix cars — we help our customers avoid bad advice, save money, and drive away safely. If something sounds off (or too good to be true), give us a call. We’ll help you sort fact from fiction, and keep your vehicle in top shape.

📍 Located in Sanford, FL

📞 Call 407-322-8415 or schedule an appointment today