I don't think it will hurt anything. Heck we ran with ours like that for about a full year and we full time. Like any other mechanical beast, it should be changed, but this certainly isn't life threatening, at least in my opinion. I had no idea ours was in need of changing, we bought the bus and I thought that was just the way it was. The things you learn as you get into it<grin> But, easy access on the D60 to change it, and easy to do. Much easier than a new rad, CAC and oil cooler<grin>