Mechanic reveals one thing that means you should walk away when buying a second hand car

Cars are expensive - that's a fact.

So for many of us in the cost of living crisis, it can be a smart choice to buy second-hand if you spot a good deal.

There are of course things to watch out for when buying this way as sometimes there's a catch.

Thanks to one mechanic, people have realised a major red flag to look out for when you're in the market.

TikTok user @jackofallbeards shared a 'Buyer Beware' video to help out other fellow drivers when they're out buying a new set of wheels.

At first, the Jeep shown in the video seems to be totally normal with nothing to it.

Jackofallbeards/TikTok

“This is a 2015 Jeep Cherokee, 159,000 miles. You’re gonna see a lot of vehicles like this on the market right now,” he explains.

The mechanic described that it's not the specific vehicle that he is about to warn about but second-hand vehicles in general.

“I want y’all to look out for oil on the dipstick. Near perfect, super clean.

"That itself is not a red flag.”

Moving on to the oil cap, the bearded driver reveals the real problem. Strings of some thick substance can be seen as he pulls off the cap.

"You see how it strings? That means they put some super thick stuff in here," he continued.

Then, he goes on to show how this thick oil can affect the car's performance.

The video cuts to the man firing up the engine which he describes as "quiet" and normal.

Monty Rakusen/Getty

However, when he revs the engine, a rattling noise can be heard which is believed to be an indication of future problems.

“If you ever see the oil get stringing off the oil cap like that, run away,” the TikToker advised.

“She needs a motor."

In another video, the mechanic says he reckons the previous owner might have used a thicker oil as a temporary fix for an issue. Despite probably being effective, it's likely to mask a more serious underlying problem.

"dude I buy cars man. that's good advice. I never knew that. I mean I know they put stuff in there but I always wondered," one user said, happy to have learned a new trick.

Another wrote: "Great public service announcement!"

A third replied: "thank you. I'm a retired single woman looking for a vehicle, so thank you!"