Engine carbon clean?

[StephMurphy]

Are these worth the money? Do they really achieve much? Anyone had it done and been pleased with the results? I'm thinking of having it done on our old workhorse 2.0 TD Hyundai Tucson.

[PaulKemp]

Snake oil.
You can chuck some Redex through it and achieve similar

[Fore Left]

Walnut blasting on a highish mileage direct injection engine is definitely worth it. Search how gunked up the intakes get. Terraclean on the same engine would have little to no benefit at it'll only be cleaning the cylinder bores.

Terraclean on a non-direct injection engine. Maybe. Some people say it makes the engine feel 'like new' others noticed no difference.

[tapkaJohnD]

https://www.youtube.com/watch?v=xIijYgvxW0g

This seems effective (and exciting!) although I suspect it contributed as much to climate change as a small African country.

Others just spray water into the air intake!