i wish to purchase a subaru with 23000 miles. under the hood i noticed what looked like soot...whiteish. is this leftover from a flood. car had two owners and the last for only 7 months before it went to an auction. current dealer purchased it out of state from an auction. after my visit dropped the price quite a bit. how ot know if this car was in a flood.

If it has brand new carpet, there is a clue. Or mold and odor on old carpet. White substance under hood could be emulsion -yes- water and oil really can mix and produces a white substance. There is a reason the second owner only had it for 7 months and got rid of it at auction for whatever he/she could get. Otherwise you list your car for sale and not dump it at auction. Avoid this car in my opinion. You don't say the year but low mileage or not something is not quite right

I just looked at your other question and TST is spot-on I shold have thought of that. Get a Carfax.!!

Do a DMV title search... If anything turns up that says or has " Salvage "on it , AVOID IT LIKE THE PLAGUE. It means an insurance co. wrote it off as a "total" .Forget mileage... you can buy a used speedo on Ebay for less than a hundred bucks.Trust you "GUT".