Are engine cleaners junk or legit?

[Submariner]

A recent post from Camino got me thinking - are all of the various engine cleaner products beneficial or junk?  There are lots of products that claim to clean deposits, injectors, etc but what is the reality behind these claims?

[shp4man]

A recent post from Camino got me thinking - are all of the various engine cleaner products beneficial or junk?  There are lots of products that claim to clean deposits, injectors, etc but what is the reality behind these claims?

Dirty injectors are rare these days unless you've run some contaminated fuel or something. Direct injection gas engines really do carbon up and cause problems, there is special cleaner for that. I don't know how well the pour in the tank stuff works.

[CaminoRacer]

Nothing much you can do for direct injection since tank additives still won't touch the top of the valves. Apparently Mazda's SkyActiv engines run the valves hot to burn off deposits.

I don't put a whole lot of faith in cleaners but they're a cheap thing to try if an engine is running funny or sluggish and it's not due to the spark plugs or coils.

[JWC]

In classes at the dealerships, we were told that using warranted fuels will prevent deposits that clog up fuel systems. Many small mom & pop places buy gasoline that is cheap because it doesn't have the additives that warranted fuels have, plus the octane ratings are not always what is advertised.

Of course that training ended when aftermarket companies came in and showed the managers how much money can be made by flushing the fuel system.

[MX793]

Nothing much you can do for direct injection since tank additives still won't touch the top of the valves. Apparently Mazda's SkyActiv engines run the valves hot to burn off deposits.

I don't put a whole lot of faith in cleaners but they're a cheap thing to try if an engine is running funny or sluggish and it's not due to the spark plugs or coils.

Seems like running a hybrid of port and direct cylinder injection address buildup on the valves.

[cawimmer430]

How long (years/mileage) until the carbon build-up from direct injection becomes critical? Will I notice this say in engine performance and perhaps worsening fuel economy?

[JWC]

How long (years/mileage) until the carbon build-up from direct injection becomes critical? Will I notice this say in engine performance and perhaps worsening fuel economy?

With the autobahn, just take your car out and floor it. We used to call it "blowing the engine out". In the rear view mirror you'd see gray smoke. I cured a couple of cars of misfires doing that.

[Submariner]

I've read several reviews (and watched several videos) all saying great things about Seafoam...have to do more research but it's a start...

[FoMoJo]

Seems like running a hybrid of port and direct cylinder injection address buildup on the valves.

Seems a few manufacturers are doing this on some of their engines, Toyota, Ford.  Apparently port injection is advantageous at lower RPMs and direct injection is advantageous at higher RPMs as well as having cleaner valves.

[Submariner]

https://www.youtube.com/watch?v=w9fTKZN0Eps

[Galaxy]

I love that channel.