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That one time SeaFoam actually worked

I’ve noticed that my Infiniti M35 seemed a little bit sluggish on the throttle. Not really bad, but i tend to drive that car somewhat aggressively and just felt a bit of lag and uneven performance.

I figured I’d waste some money on a bottle of snake oil and bought a can of SeaFoam, and added it to a nearly empty tank. I took my daughter to day care, went to class and let it sit with a warm engine for an hour or so. After I gave it a good, old fashioned “italian tuneup”, driving hard for about half an hour on the freeway consuming the majority of the remaining fuel.

With the tank nearly empty, I then added another bottle of SeaFoam to thetank, and filled the tank with the same fuel I normally buy.

Surprisingly, it does seem to be more responsive and accelerates more smoothly. It also seems to be running smoother cold. I’m not a huge believer in the stuff, but it did seem to help in this case.

I’m curious if anyone would have any insight on what, if anything, the SeaFoam might have cleaned, and of it’s a false-flag and if the problem will return once the SeaFoam present in the tank has been consumed?

Sea Foam is good stuff but I do believe you are supposed to use half the can directly to the throttle body to clean that out, then dump the rest in the tank. It smokes like crazy in the garage but does clean the throttle area.

Hmm. Is it possible then that the SeaFoam is just influencing the fuel performance, and it dodn’t actually clean anything?

I can’t afford to add a bottle of sea foam to every tank :slight_smile:

A regular customer brought his van in for regular service and left a bottle of expensive snake oil to add but adding it was overlooked. The owner called me that night many hundreds of miles away just to tell me how great the additive worked. I didn’t have the heart to tell him he was dreaming the benefits but I did add the bottle the next time he was in for service but there didn’t seem to be any improvement then. It was a really mysterious product.


You don’t need to add a bottle to every tank. Once it cleans the engine out, it’ll stay clean for a good while assuming it’s running right. I seafoamed my truck something like 3 years ago and haven’t needed to do it since.

It is entirely possible this is pacebo! especially since the responsiveness issue is pretty subtle here. I might just be trying to justify putting $23 of snake oil into my fuel tank :slight_smile:

But it does at least seem a little more punchy than it was prior. Kind of wondering if it cleaned the injectors or fuel lines? Not sure if that would make any sense. I just have a hard time seeing a quart of sea foam doing much of anything when diluted into fuel, even if it was added to a low tank, that’s still a few gallons.

Maybe if the tank was actually empty, I know it is a good solvent (i’ve def. cleaned parts with it), though I sort of doubt if it would be a good idea to try to run your car on SeaFoam alone.

ehh, yeah. IDK. I dumped a lot of sea foam into the tank and vacuum lines of my rusty El Camino and later my Volvo and it never seemed to really do anything.

Of course that doesn’t mean that SeaFoam doesn’t work, those vehicles had other problems. I just haven’t seen much benefit.

You keep calling it snake oil, but you’re treating it like a magic potion. It will fix specific things. Namely, it will fix certain accumulated deposits in engines. It will not fix bad spark plugs, or a blown head gasket, or a burned out headlight. If the vehicles had “other problems,” then someone needed to fix those other problems.

Seafoam is not snake oil. It doesn’t claim to do unrealistic things. It claims to clean the internals of the engine, within certain limits. True snakeoil claims to do unrealistic things, like increase horsepower and gas mileage simultaneously, or make your engine capable of running for thousands of miles without any oil in it.

Snake oil is for suckers. Magic potions are for Harry Potter fans. Seafoam is for people with engine deposits. The distinctions are important.


I’m exaggerating a little here because I just don’t really believe in the stuff from my personal experience. But I also understand that my experience is biased, and I also understand that some people swear by the stuff.

I’m sort of trying to sort of balance that out.

As I’ve stated elsewhere, I just don’t see how adding a little bit of solvent once or twice to several gallons of gasoline will have any one-time, lasting effect. Applying it directly via the vacuum is another thing entirely. OTOH it did seem to work, so I’m definitely Ok with being wrong, and that’s what I am posting here.

Given how I applied SeaFoam, could it have theoretically resolved the symptoms I am describing, and if so, how?

If the sluggishness were caused by sticking valves, then yeah, it could have. But that’s not the only cause of sluggish acceleration. That’s where my magic potion comments come in. Seafoam can’t diagnose the cause of your problem for you. The proper procedure is to figure out why the car is sluggish, and then apply the proper fix. That may or may not be Seafoam. But it’s… Rather silly to apply Seafoam without bothering to diagnose the problem and then conclude that Seafoam doesn’t work.

What doesn’t work is the guy diagnosing the problem.

I would agree with that completely.

But I don’t have the experience to easily diagnose a slightly sluggish acceleration and dumping some SeaFoam into the tank is a heck of a lot cheaper than hiring someone who does - especially for something that is more of an annoyance that is a reflection on my driving style than an actual problem - if that makes sense.

My question was more about if the solution was actually as plausible as I thought, given that I was sceptical that it would actually work.

If there was a resounding “no, that could not be accurate” then I’d just assume it was my imagination, and either have it looked at, or wait and see if it starts to affect daily driving. It is a 10 year old car after-all.

SeaFoam™ cured my cancer.


It will not fix a burned headlight…? … snake oil

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Makes pretty good blinker fluid though.

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Always a comedian in the bunch. It is a solvent and cleans carbon. I’ve used it to clean the throttle body and it does a good job on that. Mainly for a rough idle rather than acceleration. You can also use it as a gas stabilizer but I don’t and use B&S instead. It makes no great claims on the can other than what it is intended for. So agree with @shadowfax, comparing it to snake oils is like buying an engine degreaser to wax your car. Different products with different purposes.

I guess time will just tell if the system was cleaned to help acceleration or not, or if the octane was just raised with the additive. Really I think the directions are to add a can or 1/2 a can to 10 gallons of gas, not two cans to an almost empty tank. So when the tank is filled again, we’ll just see if anything is improved. By the way though, it doesn’t take a mechanic to take a look at the throttle plate to see if it is caked with carbon and to know it should be cleaned.


To be clear, I added one can to the almost empty tank, drove most of that out, then added another to the full tank.

I let it run a bit to make sure it wasn’t going to fart out then normally around town for a bit after that. During that trial it ran fine, and it ran fine on the highway. I figured the worst it would do is cause it to stall, being that people spray the stuff directly into the intake.

If there was any indication of trouble, I’d just push it over to the pump and fuel up.

I’m happy with Seafoam. My Koehler powered lawn mower that has always been fed non-ethanol gas has always be hard starting, yet after adding a double dose (2 oz/gallon) initially, and now back to single dose, starts quickly.
Haven’t yet used it in my car, TopTier gas seems to keep it clean.

The name of the product seems so horribly stupid that it’s hard to imagine it’s worthwhile.

@shawn_kearney The name of the product seems so horribly stupid that it’s hard to imagine it’s worthwhile.

I remember hearing of the history on a local car talk radio show but couldn’t remember. It goes back to 1930 in Indiana and then to Minneapolis as an auto product.

I’ve never used that product, but one time my Corolla developed a sort of annoying jerking misbehavior in slow speed neighborhood driving and a fuel injector cleaning treatment product added to the tank helped noticeably. I used a product called Clean Power as I recall , added it to the gas tank per the instructions. I only had to do this once, and that was at year 20 appx, of a 26 year timeframe of owning the car. I can’t guarantee the treatment is what fixed it, but if it didn’t I don’t know what did, and the misbehavior has never returned.