Carbon Cleaning Valved

[bobski1]

Currently have the intake off and the valves are quite heavy with carbon, currently looking for a mobile person to come and walnut blast of carbon clean but failing that wouldn't mind doing it myself but just wondering what people have used to do so, is it a case of coating in brake cleaner and going at it with a plastic brush?

[ssray]

Nitromores (even the modern stuff) will help with the carbon

[tapkaJohnD]

Carbon, of course, will burn - it's called charcoal. So get it hot enough, give it plenty of air and:

https://www.youtube.com/shorts/hOE-WdOaMXU

[Smint]

What we used to do when engines were simpler. was whip the head off give the head and tops of pistons a full decoke and re-grind the valves back in, taking the opportunity for new valve stem seals which would be in the head gasket set, might slip a set of new valve springs in too depending on how the compressed.

[GreenV8S]

bobski1 said:

Currently have the intake off

Do you mean you've got the head(s) off?

Taking the intake off would typically enable you to see the backs of the valves but not enable you to clean them.

[InitialDave]

GreenV8S said:

bobski1 said:

Currently have the intake off

Do you mean you've got the head(s) off?

Taking the intake off would typically enable you to see the backs of the valves but not enable you to clean them.

Direct injection engines can be quite bad for building up clag on the back of the valves, as there's no fuel wash to keep them clean - with the intake off, you can clean this off e.g. by walnut blasting.

[Smint]

InitialDave said:

Direct injection engines can be quite bad for building up clag on the back of the valves, as there's no fuel wash to keep them clean - with the intake off, you can clean this off e.g. by walnut blasting.

ISTR reading Toyota use a secondary injector or similar on the 2.0 litre engine in their hybrids which bathes the intake valves with fuel to help prevent carbon build up.

Diesels with poor EGR designs (are there any that are not) would say hold my beer when it comes to choking the entire intake from EGR to combustion chamber.

[GreenV8S]

InitialDave said:

Direct injection engines can be quite bad for building up clag on the back of the valves, as there's no fuel wash to keep them clean - with the intake off, you can clean this off e.g. by walnut blasting.

Doesn't that leave the blast media in the engine?

[InitialDave]

GreenV8S said:

Doesn't that leave the blast media in the engine?

You do it with the valve closed and suck it out the port again.

[Sardonicus]

InitialDave said:

You do it with the valve closed and suck it out the port again.

< This, walnut blasting is perfectly safe if carried out correctly , if the manifold is off the car cellulose thinners/gunwash will strip the st outta carbon soak then toothbrush , same applies to used pistons .... come up like new when soaked

[bobski1]

ideally would love to walnut blast it but nobody near me does it mobile and those that do are not interested in the distance given for very little work.

I think I might try the cellulose thinner and just leave it on there for a few hours with the valve closed and see how it goes, scrub with a brush and suck out what is left.

[TwinKam]

bobski1 said:

ideally would love to walnut blast it but nobody near me does it mobile and those that do are not interested in the distance given for very little work.

I think I might try the cellulose thinner and just leave it on there for a few hours with the valve closed and see how it goes, scrub with a brush and suck out what is left.

Use vacuum created by a pump or compressed air, do not use an electric vacuum cleaner...