What is the likely effect of doing this over time? (Gas in radiator, misfire on one cylinder (P0301); gotta be the HG right?) Actually runs okay, or seems to. @NLXTACY and @Kay9Cop have had good luck with sealants, but they were also planning near-term rebuilds and I'm not sure that's in the budget. I run maybe 6k miles a year. Thanks for any help!