Mechanic Scotty Kilmer's advice for avoiding an unnecessary trip to the shop: "They don't want you to know."

Visits to the mechanic in Spain are always a headache for drivers. The main problem is that detecting a fault in the vehicle means a significant outlay that ends up upsetting the monthly accounts. Some breakdowns are very expensive to repair , others are simpler, but the truth is that there are some effective tricks to avoid going to the garage.

At least that's what popular mechanic Scotty Kilmer wanted to convey. He's one of the most followed personalities in the automotive world on social media, specifically on YouTube. The expert wanted to share with his followers a tip that can save drivers an unexpected trip to the garage and a hefty bill. The secret lies under the hood.

This is the advice of mechanic Scotty Kilmer

The battery is often one of the most problematic components in a car. The Royal Automobile Club of Spain (RACE) explains that a clue as to whether this part of the vehicle is in poor condition "is when we notice that the engine speed isn't the same as when it was new and we hear a kind of rattling noise." Although many may think it's much more effective to have it checked by a professional, it's not always necessary to go to a mechanic.

Kilmer has offered a simple solution that can be implemented when the battery starts to fail. "I'm going to show you how you can fix a bad car by just tightening something ," he said in one of the videos on his YouTube account .

The professional analyzed the condition of a car that was experiencing idling problems . The problem was that it was causing the car to stall. The most striking thing was that the vehicle wasn't displaying a warning message on the instrument panel. After a thorough inspection, Kilmer noticed a problem : "When I grab the negative terminal, it wiggles all over the place."

He was able to detect that a loose battery connection was the main cause of the malfunction. This is something that goes completely unnoticed because it doesn't issue any visible warnings. Kilmer revealed that this is a tip that many mechanics "don't want you to know." To fix it, you need to tighten it so it doesn't move: "It starts perfectly, which is a cheap fix."