How often is it suggested (or safe) that you use Seafoam for top engine cleaning. After 5 years running with timing 1 tooth off (no cel or code) I wonder if I am still suffering from carbon buildup after one treatment (still pinging with 89 octane, 87 suggested). Will it do any harm to retreat again after only 2 days?

Never retreat, Brus. Always try to move forward.

 

How much have you driven since you ran the Seafoam? Actually I don't think it would do any harm--kinda' like a super heavy dose. Maybe that's what you need after 5 years. Wouldn't get in the once-a-day habit though.

 

Any other opinions?

When oil is introduced in combustion it make the car ping more easily.