Under the Hood: Add Sea Foam to keep water out of gas tank?

McClatchy-Tribune Information Services

October 31,  2017

Q: I add some Sea Foam Motor Treatment to my carís gas tank twice a year with the hope that it will take care of any water that has accumulated in the gas tank due to condensation. Is water in the gas tank an issue most people should worry about? Is Sea Foam doing what I hope itís doing? Am I just wasting my money?

ó Phil M., Victoria, B.C.

A: You didnít mention the year your car was manufactured. Vehicles built in the past 20 years have fuel systems that are well-sealed against evaporative loss, which should minimize moisture intrusion. Iím thinking the most likely way water would enter the tank would be through contaminated fuel.

Sea Foam claims to keep the fuel system, part of the intake system and combustion chambers clean. It also keeps fuel fresh and is purported to help with moisture contamination. Iím not privy to information that proves any of this, but the product does have a significant following of folks who think itís useful.

If youíre using an E-10 (10 percent ethanol) top-tier fuel, youíre already doing pretty well on cleanliness efforts, and the ethanol absorbs moisture, bringing it through the system. My í97 Chevy Tahoe has arguably the worst fuel injection system ever, and I toggle back and forth between Sea Foam and Techron every couple of months to keep the engine running smoothly. Even when I lapse and the engine becomes missy, adding either product brings back smoothness within a week or so. Ed, my fuels guru, says a bottle of quality cleaner provides about 10 times the cleaning agents of a tank of top-tier fuel.

Q: I have a 1990 standard transmission Toyota Celica All Track Turbo with just over 120,000 miles. It has not been driven for six years. What do I have to do to drive it again?

ó William

A: Cool car! Your largest concerns will be the battery, fuel system, brake system, cooling system and tires.

Replace the battery. Fuel remaining in the tank and injection system will be stale and nasty. It would be best to siphon out as much as possible, refill the tank with fresh fuel with an additive such as those mentioned in the answer above, then change the fuel filter after a few hours of running and again in a month or so. Your brake rotors will be rusty, and hopefully the parking brake wasnít applied all this time, as it could be bound up. Cleaning up the rotors would lessen the chance of fouling the brake pads, and a flush and refill of brake fluid is needed. Sticky or leaking brake calipers are possible, but not likely. Drive it and fix them as needed.

Renewing belts and hoses and draining and refilling the cooling system is a good idea. Hoses deteriorate from the inside, making inspection difficult, and you want to avoid a corrosion issues with the coolant. Itís not a bad idea to also renew the spark plugs. They didnít deteriorate from sitting, but the retaining threads are ready for some exercise. Check the tire identification number on each tireís sidewall (look for "DOT" followed by a string of letters and numbers). The final four numbers are the week and year the tire was manufactured (0310 would be the third week of 2010). If theyíre approaching 10 years, consider replacing them, regardless of tread remaining.