that photo is how a lot of Nissan engine bay's look if they had an owner that didn't know to clean them at least 1 time after the original purchase. the car came from Nissan with a coating of cosmolene on most things under the hood and if it never gets washed off it collects dust and dirt and this is how it ends up looking. nothing detrimental really, just needs the original cosmolene washed off. would prolly clean up nicely, pita when it gets this bad though.