Just looking for some advice, it’s been like this since I got the car about a month ago. Anybody know why the bumper sags like this? If so is there anyway I can fix it or do I need a whole new bumper? It’s not flush around the headlights (pictured below) and there’s a small gap between the hood and bumper.

 

Probably missing or have bent bumper support brackets or possible front end collision that was never repaired correctly.

 

^ I'd agree with the prev. A collision would push the bumper such that the mounting points wouldnt be lined up quite right. Keep in mind that a little bit of imperfection there would quickly be noticeable. See if you an check the headlight alignment. Are they both straight/tight?

 

In my experience, the fender liners and lower engine cover were designed to help stabilize the front bumper. OP doesn't mention what condition those parts are in, but without them, the bumper will sag.

 

dkmura is correct. Also the fender nuts/inserts appear to be damaged or missing based on the gap shown in the 1st picture (focus on the corner of headlight where fender and bumper meet). This looks like typical accident damage not being repaired properly. Make sure your undertray/splash shield and fender liners are present and properly mounted, then work your way up to the other items (ex: fender nuts/inserts, radiator core support, and foam impact absorber). I would suggest removing the entire front bumper for proper investigation. You may find a lot of other things needing attention. Better to just get the whole thing squared away at once vs. finding new surprises later. Luckily most of these parts are fairly cheap.
Good Luck!
-Icer

 

I am fairly new to 350z's only having purchased one a month ago but I've already been under it and have done quite a bit of work under chassis and noticed the bumper assembly.

The 'under pan' plastic assembly really does seem to do a lot to support that bumper. On most other cars I've seen you can run around without one and not have structural support issues.

I thought I could take it off and drive around with it (not in rain) until I do fluid services next week. However, noticed immediately that without that piece all buttoned up the bumper cover really becomes un-rigid and wobbly. SO I put it back fully and even fixed many of the mangled edges and nuts that had been bottomed on a few times. Bump is fully stiffened and even better than it's beginning state. The top clip is held in by the plastic type jam/nut body paneling things and those seem to go loose all over the car as they age and brittle.

The only other Z I saw was a 23k mile 06' and it had been in an accident and had a new front bumper cover. It was totally perfect except that one of the headlights had that ominous gap on one of the headlights. I passed on that one. So my guess there was aftermarket bumper that fit 90% and they tweaked it to be as good as it could be. My current has it's OE and though there it's not perfect, does not have any gap on headlights, with or without the pan cover/bracing. If you do have an OE part I'd consider replacing all worn fasteners top and bottom.