if anything, it's the junk that it broke free from whereever.

FWIW, the concentrations that come in gas are much lower than what you get when you use additives. And yes, I've seen build up from engines that run "top tier". Top tier specifies a additive concentration that is twice the legal requirement (it also specifies no less than 8% but no more than 10% ethanol). While better than nothing, Top Tier isn't a cure-all for deposits and the like.

The places that the solvents in additives can break stuff free include the tank, the filter, the injector sieves (little mesh thinggies at the top of the fuel injector) and what's stuck on the back of the valves. All but the last can stick in the tip of an injector.

It's also possible that the cleaner did its job, that flow out of dirty injectors is improved, and the car idle point has shifted.

Also, fwiw, I've done much higher concentrations (full pint to 1/4 tank) and had no idle problems. I just figured that the higher concentration would do it's work that much faster, and when the tank was really close to empty, I'd just fill it all the way up and go about my business.

Matt

 

2004 MCS with 147,000 miles. I added a full pint to about a 2 gallon tank, drove it 10 miles or so, then filled it. After that, I reset the ECU, just for fun.

If any engine should be dirty, it should be mine, with all those miles. Yet, and this is purely anecdotal of course, my butt dyno tells me the engine is running even better than before.

I'd want a full tank of the best gas I could find if my engine was running rough. If the problem peristed with Seafoam in small quantities, I'd start to suspect something else.

That's my decidedly amateur opinion.

 

our cars run really rich to keep the knock demons at bay. This really adds to carbon build up in the combustion chamber. IF you use water injection (or water/meth or whatever) this tends to not only lower IATs but also clean off the carbon in the combustion chamber. IF the carbon keeps building up (and it will, even with top tier gasoline) eventually you'll start getting hot spots and the like, and will probably start to notice some ping that the knock sensor induced timing retard can't really address. Cleaners like this can clean out the combustion chamber and piston tops and help cure this problem. This is best done when you suck the stuff into the intake track and let it soak for a while. Old school people may remember squirting water into the carb throat to do the same thing. Anyway, that's why one would want to do it on the SCed cars.

Now for the newere Prince engine, I've been reading about carbon build up that has screwed up some engines but good! I also was reading that other direct injection motors were having problems with build up on the backs of some valves (from the vapors in the crankcase vent system). Turns out that the DI engines don't clean this stuff off the way the port injected fueling systems do, so sucking some of these solvents into the intake track of the new motors might be a good preventitive as well.

Anyway, if you're just happy putting gas into the tank that has higher than legally required detergent levels, that's fine by me, but there are some good reasons that an occational dose of higher concentrations is a good idea as well.

Matt

 

Added some seafoam to my mini and the car seemed to love it! So then i added it to my Bike, Snow blower, Lawn mower, all with good results, snow blow runs alot smoother now, recomended it to a friend for the Vw he just bought with 150,000 he said the car ran better after so Go Seafoam for me!!!
Never heard of it before a few months ago then it showed up @ the local auto parts store recently so I picked some up!!!!

 

Hey Dr O, would seafoam sprayed trough the intake tract mess up spark plugs? I've never administered seafoam in this manner before and would like to try it.

 

What would be an good mileage to start and how often is it needed?

 

If it did screw up spark plugs, which it doesn't, it wouldn't screw it up any worse than putting it in the gas tank. I've done this previously to good effect on an old turbocharged Volvo. I just dicsonnected a vacuum line, from the brake booster as I recall, and put the end from the intake into the container of SF. Then I'd blip the throttle and it'd suck the SF into the intake. It could have been wishful thinking, but I'm pretty sure my butt-dyno registered a few hp back that had been lost over the years.

This method beats the hell out of taking all the intake tubing off and spraying throttlebody cleaner into the TB.

 

is adamant about changing out plugs after a SeaFoam treatement, but I've "sucked it in" and not had issues... Anyway, I change my plugs pretty much yearly and tend to do the treatments before I swap out plugs...

The earlier in the intake track you suck it in the more stuff it will clean, but be carefull as it will suck it in really, really fast. I enlist a helper to keep the car running, and use a squishy tube so that I can pinch it to control the up-take.

Matt

 

Well, it seems my car is much happier today. I'll be putting about 70 hwy miles on tonight. Hopefully that will cook off a little more crud and finish "sucking it through." Like I said, it started up much more smoothly this morning, and may have actually been a little more responsive than Pre-SeaFoam. (According to my butt dyno)

Thanks for all the feedback guys, I'll let you know how this tank finishes up. I'm hoping my issues were just the initial chunks breaking loose in my engine.

 

Start now, and use some every 5,000 miles or so.

So would a spray bottle filled with seafoam and sprayed into the intake tube (air filter off) be acceptable?

Glad it is working out for you.

 

Pre TB would clean gunk off that, but the air velocity is pretty low. Post TB has the vacuum to really suck the stuff in. Probably the best place is the grey plastic tube that goes in pre SC. I think that might be the break booster line. That can be tapped into by the side of the cylinder head by the air box...

Most of the time I use some extra IC boots that I modded for pressure drop testing. But that doesn't clean the oil off the SC...

Like I said, I'm not sure what's best.

Matt

 

you can use the grey line prior to s/c that goes to pcv valve .

 

Pics of what you're referring to? I've been meaning to use another can of Seafoam but haven't gotten around to it. If this is better than just putting it in the gas tank, I'd like some tips... TIA

 

i ran SF through my classic mini and it ran really rough and crapped out on me once...just kept revving and blipping the throttle and after a bit it started to run fine....best guess is your mini is just spitting out the crap that was gunked up in there...just run a good tankful of gas through it and u should be good to go

 

https://www.northamericanmotoring.co...he-answer.html

There's a link in there to an audi forum as well....

Basically, you suck a bunch into the intake, shut off the motor so that some of the stuff can soak the deposits, then fire up the car and let it rip!

Matt

 

sorry my kids off at school and i'm a computer illiterate sap . it's the line coming off valve cover on passenger side . it changes over to a grey hard plastic line ... and goes under the inter(after) cooler . just pull the grey line from the big rubber line going to the valve cover on passenger side(pcv valve) . start car and make sure the grey line is sucking air, you'll feel it if you put your finger over it . if it's sucking it's good . back to here and now .... so add the seafoam with home made funnel of paper very slowly while someone holds rpms at 2000 . very important . very slowly . and make sure car is fully warmed up so cylinder temps are hot !! but have patience and add it slowwwwwwwly ,trickle . so you dont hydrolock a cylinder .

 

when doing this, have whomever turn the car off while at elevated RPM and let the stuff soak in the cylinders for 15-30 min. Don't keep dumping the stuff in after the engine is off.

When you start up the car again, raise the revs a bit and watch the smoke come out!

Matt

 

I used this method and got a bunch of black smoke for a while. Did not stop and let it soak so I will probably do that next time.
I am not sure the car ran better but the black smoke seems to indicate something was knocked loose.

 

I recently did this as I was getting pinging at high loads. Sucked up some Seafoam thru the PCV and let it soak for 15-20 minutes. Poured the rest in the fuel tank. Fired it up after waiting and the smokeshow began! Car runs solid now with no pinging at all.

 

You cleansed the residual carbon deposits which raised the compression causing pinging!

 

I think it has more to do with glowing "hot spots" from the deposits than an increase in compression.

 

The increased compression ratio can be more of a factor than you think. For an R56 'S' engine with a compression ratio of 10.5:1, a layer of carbon only 10 thousandths of an inch thick on the piston face, valve faces and combustion chamber walls will raise the static compression ratio to 11:1. If it builds up to 20 thousandths of an inch thick, the compression ratio will be 11.7:1.

Needless to say, increasing the compression ratio that much on an engine where premium fuel is already recommended is inviting knocking/pinging, even without taking into account the hot spots and poor heat transfer due to the carbon buildup.

 

if it's IAT related, the timing retard and fuel dump should quenck knock. If it's hot spots, I don't think the timing retard or fuel dump would quench it. If it's higher compression ratio, then I'm not sure.... I'd expect the engine designers to put normal carbonization thicknesses into the "operational envelope" of engine management, but maybe then again not...

Matt

 

I'd think that since retarding the timing and dumping fuel will reduce the dynamic cylinder pressure, that would take care of any knocking from a deposit-induced increase in compression ratio, so that may be how the engineers decided to address the matter. The suboptimal timing/fuel settings would cancel out the performance increase you'd otherwise see with increased static compression, so there might not even be an overall power loss with the retardation and fuel dump. (I can't say the same for fuel economy, though).

 

How does this affect the car in the long term? Previous threads have said that over long mileage hauls that SF will wear down the engines internals? I don't want to do this as a "quick fix" only do be spending several thousand more down the road to replace parts that wouldn't have otherwise failed.