Below is some text (paraphrased and edited) from a question I posed about a procedure suggested by a forum member for putting SEAFOAM into the crankcase of your engine. I would be interested to learn how effective and safe this procedure really is and what experience people have had with putting solvents directly into their oil. The procedure was explained as taking a vacuum hose (like the brake booster) and running the engine to pump the solvent directly into the engine crankcase (according to directions on the can), then letting it stall out and letting the solvent 'soak' (I guess?), and then running the engine again. My questions are:

Doesn't this expose the engine to dislodging a large oil clot? Doesn't it change the lubricative properties of the oil in the engine by diluting it significantly and possibly causing damage? Do Ford mechanics actually do this procedure at a dealership? Should you really let a vacuum hose suck SEAFOAM into the crankcase? Why would you want to let the engine stall out and leave it 'soak' for a few minutes? Wouldn't this damage sensors like the exhaust gas/O2 senors? Wouldn't it coat the sensors in some way (like with more carbon) and/or the cats? It just seems that there would be too much risk of long term damage (by diluting the oil) if you did this. How would you even be able to measure whether the procedure was effective or not? Wouldn't you want to change your oil immediately after the procedure to flush out the dilution and sludge? Does this really work and is it safe? I've used SEAFOAM in the fuel system and I do think it works there, dislodging gunk in the system and injectors, but I really wonder about the crankcase idea.

 

Fisrt off, using a vacuum hose to "suck" the seafoam into the engine isn't really putting it in the crankcase, it's being sucked into the intake system and eventually into the combustion chamber through the intake valve. I don't really see how this would harm the engine any more than putting it into your fuel tank, much the same result, only you're getting it into the flow before the injectors. I don't see any harm in it. It's just a detergent, much the same as techron is.

Second, I'm guessing the reason you'd want it to stall out and let is soak is so that you ensure there is an adaquate amount of the seafoam on the valves, etc and it has time to sit there and work. If you just run a can through without letting it sit it probably won't have enough contact with the deposits to clean the heavier ones. Now I have no experience with seafoam, so I'm just guessing.


Now, about putting it directly in the crankcase (through the oil filler, or where ever) I'd be curious to see answers also. Personally I think you're right, I wouldn't want to leave it in there too long. I have a feeling it's a high detergent agent and is going to knock loose all kinds of nasty stuff, so I would think put it in, run it for a day or so and then do a complete oil change.

 

I have put seafoam in the fuel system, crankcase and through the intake. When you pull it in through the intake you are cleaning out the cylinders and valves. I am always amazed at the amount of smoke that is put out during this process. The smoke is all the carbon and junk being cleaned out of the cylinders and valves. As far as why you let it sit, thats just what the can says to do. I believe that letting it sit is making sure it has time to work.

I used seafoam in the oil of my explorer when I first bought the truck. I poured it right into the oil and drove the truck for a day and then changed the oil. You don't want to leave it in there long; just long enough to clean out the junk.

I have run seafoam in 7 or 8 vehicles now without a problem. They run a heckuva lot better after the seafoam treatment.

 

I ran Sea Foam through my 97 Expy and noticed an increase in MPG and it seemed to have better throttle response as well. I've heard you should replace the plugs and O2 sensor after using it, but I did neither and have had zero problems.

 

I used on my '01 Expy with great results. I'd add it into the crankcase a few days before an oil change to let it clean out the build-up. I'd also add 3/4 a can to the fuel tank to clean out the injectors and put 1/2 a can through the brake-booster line. Smokes ALOT but the car runs alot smoother afterward.

 

Now THAT's funny.......

Carbon is a by-product of combustion. It doesn't burn. I guess you could say it's "already burnt"?

The smoke you are seeing is the SeaFoam being burned by the engine. Several other things, like Marvel Mystery Oil, transmission fluid, etc. that have been poured in intakes over the years by people will cause this same smoke. But, it ain't the carbon burning.

 

I have never heard of replacing the plugs and O2 sensors after using it. I used seafoam in my 97 F150 and got the same results as you, improved MPG and increased throttle response. I think I will be running a can through my truck again. I ran the last one around April.

 

This is one of those things that is recommended because of a problem that "might" be caused by using SeaFoam.............

As the detergent does it's job, there will be some carbon flakes that will break loose and pass through the engine. Some of these, if large enough and shaped correctly, "could" become wedged in the plug electrode and cause the plug to either fire poorly, or possibly becume shorted out. There also exists the same scenario with the 02 sensor.......carbon becoming lodged on the probe and causing an incorrect reading. Like yourself, most prople won't benefit from the replacements unless carbon fouling becomes apparent.

Just a side note.........after you add SeaFoam or Marvel Mystery Oil (if you pour it in the intake), have another person blip the throttle while you hold a towel in front of the exhaust. You'll be amazed at the carbon fragments that come out.

 

Interesting comments thus far, thanks.

So, what is it that we are doing when we cause the truck to stall? How does it stall? Do the plugs get soaked, or is the intake fuel/air mixture that drastically (and immediately) altered (enriched beyond factory specs or controllability by the engine itself)? How is forcibly stalling an engine a good thing?

So far, from your feedback, some of you are telling me that the following is how you are 'measuring' effectiveness (and safety/reliability) of this procedure:
1. increased throttle response
2. increased mileage

How long do results 1 and 2 above last for the average driver? How do you measure the effect of diluting the oil, especially in the stall procedure?

 

How long do results 1 and 2 above last for the average driver? "

That all depends on how & how far you drive.

How do you measure the effect of diluting the oil, especially in the stall procedure?

As was stated before, when you suck it in through the vacume lines, you DON'T dilute the oil. It goes into the intake and cleans the fuel system.
When added to the crankcase, then & only then does it cleanall the areas that your oil goes.

Does it help???? Some people think so.... Some think as I do that for MOST people & in most cases, it isn't needed.

 

OK.......let's see how far I can go on this..............

The engine is purposefully stalled by introducing the material into the intake in such volume that you create a rich condition that is beyond the engine's ability to ignite. In other words....too much liquid, not enough oxygen. The engine is flooded, basically.

The reason that you want to choke the engine into a stalled situation is so that you can leave some of the material in the engine in it's original state, and not have it burned away by a running engine. Make sense?

As far as diluting the oil, I have never (and will never) used any of these things in the crankcase. Only in the intake. Does some of it pass by the rings and mix in with the oil? Possibly. But the amount would be minute. So I can't answer that part of your inquiry.

What are your benefits in the long term? A clean engine is a more efficient engine. The reduction of carbon in the combustion chamber will help your engine make it later in it's life. Is it necessary? Who knows? Does it help? Probably. Will it hurt anything if used properly? Nope. Like LEADER said, under most driving conditions, in engines under 100,000 miles, it's probably better for your peace-of-mind, than it is for your engine.

 

Boy that is 100% correct Seafoam is a solvent/oil mix it will smoke a lot and IMHO clean no better than just using some ceap plain mineral spirts.
bruce

 

thats not true, I have seen people put only 1/3 of the bottle into the break booster and TONS of smoke piled out, I put 1/3 of the bottle into my car and hardly any came out, If it truley is just the seafoam burning this wouldn't happen.

 

I was curious if it was just the Seafoam causing the smoke too, so I put some through my Expy when I got her new. No smoke. There are a few post on here with several theories about the smoke.

 

I've successfully used Seafoam to clean out 2 stroke engines, (chainsaws and weedwackers). I also run a can thru my vehicles gas tank every 10k miles.