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22 January 2008
I ran a search on Seafoam; if people used it, where they injected it, the results, etc. I didn't quite find the answer I was looking for. I'd like to give it a try but would first like an experienced mechanic or user's advice.

Thanks for reading.

I was skeptical, I did the treatment on a fuel injected Camry and the difference was amazing. It ran a lot smoother after the treatment. The owner originally had the throttle body professional cleaned treat the rough idle problems but it didn't make a big difference. I poured some down the throttle body, some went into the brake booster vacuum hose and some in the tank. Tons of smoke came out and the car ran awesome after it was all said and done. There are a lot of threads on various forums and people seem to swear by it. Made me a believer....
I once tried soaking valves and carboned-up pistons in a few different chemicals, including Sea Foam. After a couple days I took the parts out and tried to remove the carbon. No difference that I could tell. The carbon wouldn't wipe off, seemed just as hard as the stuff that didn't get the treatment. Maybe it somehow burns off easier in a combustion chamber, but that wouldn't help deposits on the valves at all.

I dunno. The stuff is cheap and I can't see it hurting anything, so give it a try and see what it does for you. Then post back.
FWIW, My mechanic recomends it. I've used it in all my vehicles as a preventative. Seems to be fine.
My brother used it in his Integra, with positive results. It smoked alot while doing the treatment which from what I understand is a good thing as relayed from a Mechanic friend. Car runs smoother and better gas mileage I might add too... I would say defineatly something to try in a higher mileage car with carbon buildup etc...
Ok,all these responses helped a lot. I guess the only thing that remains before attempting it is to find out where is the best place to inject the stuff? I'll be using the liquid version.

Should I let the PCV hose suck it in? Pour some through the TB? Both? Once I get this info I'll give it a good try and post my results and ultimately give the seafoam challenge for the NSX a solid review. Thanks guys.

It has some use in older carbureted engines but modern fuel injected engines don't get carbon buildups that would benefit from treatment with Sea Foam. Save it for your outboard and lawn and garden equipment.
The one thing I've learned from this site is, if Briank, Larry Bastanza, or Rob {Ron98}, chimes their 2 cents in, you can pretty much take that to the bank.:wink:
I tried the stuff in my 94 Ford Ranger a few months ago. It was idling rough. So I dumped a little in the tank, then fired up the motor and had the vacuum line on the brake booster suck the rest in, that went directly into the intake manifold. God that think smoked like crazy and looked like smokey enough that the neighbors thought my truck was on fire. Kinda embarrassing. Few minutes later, drove out of the neighborhood and tried to burn it all out down the highway looking like a bad gross polluter. 5 miles later, it was clear.

End result.... Didn't notice a difference. Next day, truck idled like pure shit and would cut in and out while driving. Not safe. Figured maybe the smoke somehow killed my O2 sensor. For some reasons, I changed spark plug wires and added +4 plugs. Truck ran like a champ, better than it's ever ran even when almost new. Odd.
92 NSX, check this link out:


I'm sure BrianK is knowledgeable of a lot of things. However, a friend of mine, an experienced mechanic, has shown me visual proof of the results of a properly administered can of seafoam. After using it on a 2002 RSX type S ( fuel injected mind you) we took a look inside the intake manifold and saw that what was once a previously an oily, carbonated mess, is now cleaner by IMHO at least 80%. This was an RSX with almost 127k miles on the clock. As far as mechanical performance goes I don't know it's true effect but I don't see how a cleaner IM wold hurt it. :biggrin:

I know a lot of these responses sound like an advertisement but it's hard not to when the product has been proven to show some positive results. As far as
the scenario afore mentioned by KoolAid, it didn't seem to worsen the problem the truck was having so I have yet to read about a negative outcome.

With all that being said I'll be trying it today, tomorrow at the latest and will post my results.

seafoam seafoam seafoam :biggrin:

it will bring the fire department everytime. :wink:

I have ran seafoam through a couple of my cars.

besides the cRaZY smoke screen you get, personally I have "noticed" better mpg and idle.

as Brian said above... efi engines do run very effectively however sometimes carbon does build up. If you consistently drive the nsx at lower rpm and never really get up in to the higher rpm echelons of bliss, you might have some carbon build up.

seafoam works on the same basis as water ( very small amounts ) in your engine + detergents.

very small amounts of water will generate steam in your combustion cylinders. this steam will over time work loose the carbon build up on the pistons and heads which has many benefits including returning the engine back to its original compression, removing heat spots caused by carbon build up, help lower the detonation thresh hold, increase fuel "octane", cleans out the exhaust manifold and exhaust system for less ex flow restrictions.

my problem with seafoam is distribution.

since the directions on the can to taken an vacuum tube such as the brake booster and "suck" in the fluid a little at a time. only 1-2 cylinders closes to where the hose comes in will get the fluid since the seafoam is not suspended in the air but rather in liquid form and flowing against the walls of the intake manifold.

it is imposable to get even distribution in to every cylinder.

Also if you try the seafoam treatment, only a little fluid can go into at a time.

If too much fluid gets suck in at a time, this can result in hydro lock, a condition where water displaces air in the cylinder and since water can not be compressed, all the force of the rotating engine is applied on the rod bearings resulting in a spun bearing.

I always had this remedy in mind where you get a handheld pressurized spray bottle. the ones where you pump up and then hold the trigger resulting in a consistent spray of fluids. you can get these for 5$ at Wal-Mart. Anyways, because the mist is much smaller and you can actually inject the fluid upstream in the intake tube before the air splits to individual intake runners, you will probably get a better distribution of fluids and the seafoam product will be more effective.

for all the trouble. I would pass. Instead I would take the NSX out for a spirited drive on the freeway and put to good use the awesomeness of the complete 8000 rpm rev range.

If any of you are interested in water injection, it is a very effective way to keep your engine clean from carbon and to increase octane of the fuel by slowing the flame front.

Warm regards

Awesome response Rob, we were actually thinking about how we could distribute the seafoam throughout each cylinder. I've heard of people running some of it through the fuel tank. I'd imagine it would get to the cylinders in this way pretty significantly.

yes you can run it through the fuel tank but the concentration will be next to nothing. also i do not know if the fuel and seafoam will mix.

do not put this product in your crank case or mix it with any other oil like they advertised.

run it directly through the intake manifold with a spray bottle... or not at all.

get a spray bottle and give it a shot :)

tell us how you like it. also do it in an open lot... if you like living on the edge do it in your garage and see the neighbours come running..... to watch... not to help with the "fire" :D
like ron said, carbon will build up if you do not drive the car the way it was intended to be used. this is a common issue on motorcycles that are ridden by 'born-agains' and do not get their neck wrung out on consistent basis.

if you choose to use this kind of a product i strongly recommend using an aerosol-can product made by yamaha and sold in bike shops. the mist gets nicely dispersed throughout the cylinders and actually works quite well. no, it will not fix your leaky guide seals etc. but it will clean the injectors and remove the carbon. i have no experience with seafoam brand but i do not like the application process of just pouring it in.
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I gotcha swerve.The entire reason I'm doing it is because I just bought the car from someone and I've been doing some other maintenance on the car. I have no idea how the previous guy drove the car but I do know that the clutch fluid was so filthy it stained the reservoir, the MTF wasn't much better,and he had an intake installed that he painted himself. I took off the filter to clean it and discovered a large piece of masking tape inside of the filter! So I'm pretty much trying to do everything I can to keep the car healthy(er). :biggrin:

while working at a dealer as a kid, i can't even tell you how many times i was asked by the techs to take the car (mostly m-bmw's) out and give it an 'italian tune-up' as the owners would just plug along, not run it through the rev range, foul the plugs and carbon-up the works etc. it was lots of fun for me and easy money for the dealer.
you can drive your car any way you want but no matter how you look at it nsx is tuned for performance not economy and it will appreciate the occasional exercise.
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Ron98 = Rob not ron :biggrin:

meh, give it shot. it wont hurt.

make sure to do it right before an oil change. the seafoam will leak past your rings into the oil so change it out once the treatment is over.
Wow, Rob you're reading my mind! I haven't posted on this thread yet because after thinking it over I was gunna do it right before next oil change. :biggrin:

BG makes a superb cleaning system that I've had very good results with.

It's a 2 step process where a pressurized head unit sprays the "chemical" into the engine intake while the engine is running. After this is done you use the second chemical "spray bomb" which will ultimately kill the engine.

Then it's your turn::wink:

Wait 15 minutes. Start the engine and kill every living insect within 20 yards and watch passers by run for cover. :eek:

I last used it on a 560SL that wasn't driven regulary and it made a heck of an improvement on the idle, acceleration and driveability.

The diesel truck guys seem to like Seafoam too.

Re: Some useless trivia

This probably has no application to the NSX, but some of use it to decarbonize the seals on our 13-B Mazda rotary race engines. On those, oil is injected at the big honkin' Weber carburator. In addition, the engine builder recommends Red Line 2 stroke oil added to the gas as well to lube the seals. But sometimes they can get too much oil and the seals can get carbon'd up and stuck open.

To use the stuff, we get the motor up to race temp, then pull the plugs and inject some SeaFoam into the chambers while turning the motor over by hand to get it in all chambers and on all seals. Let it soak awhile (30-45 minutes), fire it up, burn the stuff off and piss off everyone in the paddock. But it's a great tune-up according to some old timers: I'm still not sure myself, but that's the theory.