So, i'd like to clarify, the improper way to run Seafoam through the car's intake system is to use a vacuum line that only feeds one cylinder. If you used the brake booster vacuum line, you've only been feeding a single cylinder.

In this picture below, you can see the brake booster vacuum line directly feeds a single runner (either Cyl 3 or 4). This means your Seafoam is not at all distributed to any other cylinder.





In this picture below, you can see the PCV vacuum port feeds the plenum before it divides into the 6 runners. While you'll never get perfectly even distribution, hopefully some of your Seafoam gets to each runner.

 

I never even thought of that before....

Good call!

 

Good point. On newer vehicles with an electric PSV (evap Purge Control Solenoid), use that hose - it should be sited from the factory for optimal distribution of evaporative emissions (fuel vapors). In general, try to get as close behind the throttle body as possible.

 

wow i had quite a few people tell me not to run through the pcv and through the brake booster. i did get way more smoke through the brake booster thats for sure

edit: im an idiot. didnt see the forum this was in

 

Hehe no offense....!!! But... ??

I think its been pretty clear that the 3.4l seafoam treatment is through the PCV hose for at least the last 7 years I have been a member here!

 

I hope that's the case for everyone. These posts lead me to believe otherwise:

https://www.yotatech.com/forums/f2/s...65/#post637781

https://www.yotatech.com/forums/f2/s.../#post50598716

https://www.yotatech.com/forums/f2/s.../#post50736894

https://www.yotatech.com/forums/f2/s.../#post50736894

https://www.yotatech.com/forums/f2/s.../#post50736894

 

Good point, personally I recommend putting it in the gas tank.

 

not everyone chooses to search and not everyone has common sense to see its only hitting one maybe 2 cylinders from the booster. But yes the pcv is usually the best place on all motors.. usually...

 

Wow! I can't believe it. Always seemed obvious to me. Doesn't the can say to put it in the PCV hose?

Anyways, interesting. Glad you posted this. I am sure its going to help a lot of people.

 

Good post.

Let me ask a question. Adding it to the gas can help clean injectors and the complete gas system. And sucking it into the engine is a much higher volume of seafoam and tends to clean the valves and cylinders better. Remember that sucking it in won't clean the injectors.

I guess that wasn't really a question but more of a statement.

 

Guys ever notice when you put it in your gas tank your exhaust is white?

 

^ not for me, only when i did it in the intake

 

My guess would be, No. This would be because the seafoam is diluted heavily by the gas.

When it's used in the gas it's mission is to clean the fuel system including the injectors.

When used by sucking it into the engine by a vacuum line it's mission is to breakdown and remove the carbon buildup. The high concentration of seafoam and the carbon being burned cause the smoke.

 

so what color smoke are you guys seeing by pulling seafoam through the intake? white?

 

Yes white seems to be the norm at least in all my applications.

 

Ok so it is true that it doesn't actually work and the white smoke is the just the seafoam itself buring? I've never seen carbon burn white. Just curious what kind of difference or affect you guys have seen doing this?

 

I personally did a service on a car with about 140,000 miles on it and one part of the service is the sea foam clean through the intake while I was waiting on an upsell headgasket job on the same car, afterwards they called and said do the headgaskets and when I took the heads off, those combustion chambers were nice and carbon free, I swear by it since then.

 

definitely works. i didnt pass smog one day, did seafoam(with a few other things) passed the next day.

 

What did the combustion chambers look like before the Seafoam?

 

Usually a Subaru with over 100,000 miles I spend about an hour scraping and cleaning carbon from both heads. This car just about 10-15 min. No I do not have a before and after comparison on the chambers of the same car, but a car that came in 20,000 miles overdue for spark plugs and 5000 miles over on his oil change, he obviously didnt take care of it, and from the thousands of headgasket jobs I have done, this was the cleanest next to the 1700 mile mishap from another dealership.