A MECHANIC has revealed a simple DIY engine check that can save you hundreds of pounds in repair bills in seconds.
Scotty Kilmer, who has over 50 years of experience in the motors business, explained the maintenance hack on his YouTube channel.
Scotty explained how you can use a key engine component as a rule of thumb to check the health of the whole system.
The condition of your spark plugs can tell you if your motor is on the blink and even reveal a range of specific issues.
In the video, Scotty showed off a selection of spark plugs of different ages and ran through what each one meant.
He said: "Here's a brand new spark plug.
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"It's not going to look like that unless you just put them in.
"But here's a spark plug that was in for 100,000 miles.
"It's got a nice tanned colour, there's no burnt carbon really.
"That means you engine's in good shape."
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However, he then held up a plug that wasn't in as good condition.
Scotty noted that the darker colour around the metal coil on the plug and the buildup of carbon on the rim were both indications that the engine was burning oil.
That would suggest an oil leak, which can have several causes.
If you see this on your spark plugs, it's a good idea to take it into a garage to determine the root cause.
But, there is a third option which reveals a more specific issue with your fuel.
Scotty showed one plug which was still in almost new condition on the lower part of the white insulator that runs through the core of it.
The tip of the insulator, on the other hand, was discoloured where it protruded from the metal coil.
That, according to Scotty, that the fuel is contaminated with improper additives or that the fuel injector is distributing it unevenly within the cylinder.
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Both could have serious ramifications for the performance of your car so if you see this, get it checked straight away.
It comes after a major car brand rolled out its final ever diesel model as it heads into a new EV era.