I did it in my HHR a few weeks back before I changed the plugs. I used the brake booster line and it smoked pretty good.

 

The intake valves don't see any fuel so I doubt the quality of gas has anything to do with it ..... it's just one of the problems that happens with DI motors.



I have seafoamed my car 3 or 4 times in the last 28K miles...... and it really smokes like a bitch and produces blackish gray smoke. If it was just burning off the seafoam it would be white ...or so ive been told.... so it must have had some contaminates in it .

 

Just because you are direct injected doesn't mean that the bottom of your valves would have any fuel on it or any carbon deposit build up there. Just clarifying the "valves don't see fuel".

 

It think it's safe to say that one characteristic of DI engines is that the intake valves are know to get deposits on them ...... So i'm fine with buying a can of seafoam every 5K miles or so and running it threw the motor.

My comment on the "valves dont see fuel " was meaning that there is no fuel running past them on the way to the cylinder .....so there isn't anything to stop carbon/oil from building up . I might pop the intake off and take a look soon..... I'm curious to see what it like in there.

 

Understood. Either way, its good maintenance.

 

if you want to see some valves from are motor then i will go take a pic of mine while my motors apart ok intake side see a lot of build up

 

That would be cool to see how good/bad they are ....... thx

 

So I finally came around to seafoam the valves this weekend..

Even after 65k KM they didn't smoke all that much.. I seafoamed twice and got about the same amount of smoke each time.. just a bit..

Guess that 94 octane petro canada gas burns well

 

this motor is direct injected, he needs to seafoam every oil change, no gas on them to clean em and if u dont seafoam, u will have very dirty valves. even seafoam isnt really enough, but it helps

 

that vac line that goes into the top of the manifold. if u can get the spray type seafoam use that, its much easier, just takes longer