I have done a search on this but can't seem to find anything consistent on it... Basically when I check the radiator cap, the coolant is clean, red, and consistently full... But Today I was doing weekly check on fluids and other things. I checked the coolant dipstick and found it was coated in a yellowish sludge that completely covered the markings on the dipstick! My mates with LS2 VEs reckon they get it too but I cant seem to see anything about it online. Is it actually normal for Gen4s to do this? My engine is the 6.2ltr LS3... Everything looks, seems and runs perfect, apart from seeing this. Is it something to do with the stuff in the coolant? Can anyone confirm if this is normal and part of the LS2,LS3s nature?