If you put too much Sea Foam in your car’s engine oil, is it harmful to the engine? [SOLVED]

Good question, Silvino.

Do not exceed 1 oz of Sea Foam per quart of oil. If you have more than 2-3 oz total over the recommended amount, I’d change the oil just to be safe. (example: if you added 9 oz to a 5 quart oil system).

Some people will drain just enough to bring it back to the recommended ratio. (example: if you have a 5 quart oil system and you accidentally added 10 oz of Sea Foam (twice the recommended amount), drain half the oil (2.5 quarts), and then fill it back up with 2.5 quarts of fresh oil.

But why? I have a tundra with 250,000 miles that was heavily neglected due to a passing soul and it went 18,000 miles on the last oil change. I have low oil pressure so what harm can I actually do?

Hi Steve,

Adding significantly more than 1 oz of Sea Foam per quart of oil will alter the oil’s viscosity beyond what is recommended by vehicle manufacturers. We do not recommend doing that. That can cause some serious problems in an engine. For more info on oil viscosity and Sea Foam, check out this article: https://seafoamworks.com/shop-talk/understanding-oil-viscosity/.

Hope that makes sense and let us know if you have any other questions!