Doesn't make sense. There is so much dirt / salt and crud getting into the engine rusting everything out. Is this a stock fender liner? Seems a bit too open. I had an 05 that never had mud and salt get up into the engine and cause rust. It would stay very clean. Can't remember what the liner looked like though.

Passenger side front

 

mine comes down further than that... it does a good job keeping crap out of the engine bay

 

Looks just like my fender liner.

 

his looks like it is pushed up a bit higher than yours

 

What year model is your truck OP? I'm on the mobile version and can't see all the info. My 04 has a similarily designed fender liner and it sucks! Luckily I don't have to drive down any nasty roads very often but when I do my engine bay gets caked with water and mud.

 

Looks the same as my 07 and old 04. I never had rusting issues even in PA but I have always thoroughly washed.

 

The truck is a 2007. I just picked it up used last month. I'm wondering if the previous owner just never washed the thing. Lots of bolts and clamps and such have rust on them. When I went to look at the truck the engine absolutely caked with mud, the dealer washed it up and now it looks like this:

 

2008 XL, did you paint all of that? That looks immaculate!

 

Thanks, yep, I repaint the entire undercarriage every spring. I've always used the Rustoleum rattle can. This year I'm going to get the same satin Rustoleum, but in the bigger can and apply by brush.

If you look in the folder that I took that pic from, you'll see the rest of my undercarriage.