Seafoam Treatment

[grimsubaru]

I have a 91 subaru impreza. I once had my subaru mechanic hand me a bottle of Seafoam engine treatement while he told me to run a half bottle of it through the engine oil and the other half through the gas tank. I placed the Seafoam treetment in my oil, and gas (when tank was about 1/2 full). Ran it for a day, and changed the filter and oil out the next.

I had no adverse problems to start, and have continued doing this throughout the years of this car without issues.

Does anyone know what the advantages are of doing this treatment every other oil change. Am I needlessly spending $10 every year. I live in a cold climate and the car has 260k and has always been parked outside. My biggest concern is that the instructions to seafoam do not seem to match what the mechanic said.

Any thoughts? Or suggestions for alternative chemicals.

Topic

[Gary]

Speaking from my experience with the stuff, adding it to the gas tank is a good practice as it helps clean the fuel system, intake, and valves. I regularly add it to my own gas tank. That said, adding it to engine oil can be good and can be bad. It is opening Pandora’s box really. The carbon from the ring grooves and such can clog the pickup screen and cause a potential failure. On the other hand it can fix dieseling and preignition issues by the carbon removal. Adding it through the intake is usually a safer bet as long as you know what you are doing(making sure not to wash out the cylinders with the stuff!). Make sure that if you add through the engine oil that you keep close tabs on the oil and as soon as its lookin really dirty, change it! I personally would not regularly add it to my oil or a customers due to the risks unless I was actually having a problem.

EDIT: I forgot to mention that the mechanic is wrong if he is telling you to add half to your oil! You should follow the instructions on the can to the letter when adding to engine oil or you can cause excess wear to the cylinders through dilution of the oil.

[grimsubaru]

I just did the Seafoam treament on my Subaru Legacy 2000, a recent purchass last fall. It has quite the history of sitting in the swamp, and once had a replaced warped head gasket (a common failture on this engine’s year).

A bottle of SeaForm is 1Pt, (16 Fl Oz), and the subaru takes 4 quarts of oil. so half bottle is just a little over recomended. I drove about 10 miles looking for a car wash on saturday night. Then changed the oil the next morning. The oil did come out quite black, but no foam or sludge, a little more dirty than I expected for such low miles. Perhaps the blackness is the carbon, after the treatment of SeaFoam. Again, I have no idea of the history on this car, so bi-annual oil changes don’t sound like a bad idea. I’ll just keep buying Mobile 5w-30 from wallmart and change it often along with new FRAM-TG3593A oil filters.

The antifreeze looks glows fine, and maintined its level. So I’m thinking the blackness of the oil is a buildup of bad oil collected from years of sitting, finally getting disolved in the SeaForm treatment.

The car does throw an error code, something about the evaporative emmisions. It goes on, stays on, but sometimes turns off on long rides. When i remove the gas cap, I don’t get the puff of vapor like normal. Could this be a rusted out gas tank? I cleaned the rim of the cap, and it doesn’t build up pressure. Shall I get a new gas cap? It could of course be the wiring, cause I see some splices. I ran my own splice parallel to the onces added. Its hard to test these circuits, I’m not sure when they activate. I started lookin into this because of the code, and my idle sometimes drops low (like 200 rpm) then quickly returns to its sweet spot at around 600rpm.

[zero]

I would advise against EVER driving a car with any sort of oil cleaning additive in it. Every similar product I’ve ever seen says NOT to drive the car.

If you really want to help your car follow the instructions to introduce it through the intake manifold. I can almost guarantee it will run better, Especially if the engine is good and hot when you do it. It’ll blow any carbon build-up right out.

[Author]

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