Hey guys lately I have been noticing my gas millage dramatically dropping, the meter says around 16.2-16.7. I also notice from my rear driver side a burning smell (almost like the smell of welding metal) near my tire. I noticed that the rotor is extremely hot, so hot that if you spit on it, it evaporated instantly.
I have not notice the car pulling to the side, just have noticed a little rougher of a ride on the highway (Was not sure if that was just because of winter tires).
Any ideas?

 

Stuck caliper. Pry the brake pad off the rotor and see if travels normally. Might have to take the brakes off and reseat/replace the brake pad.

 

Yup, most likely you will need a new rotor and fresh pads too.

 

And go ahead and replace the other caliper as well.

 

Like already said it's a stuck or seized up caliper. You'll need either a new/reman caliper or an overhaul/rebuild kit from Nissan as the caliper piston on that wheel isn't retracting. Even if you can get it to temporarily free up it'll happen again soon if the real issue isn't resolved and if one is seized you can bet the other isn't far behind and should be replaced/rebuilt as well.

I had the same thing on my G35 where it started as a constant pulsation feeling at speed and the car felt sluggish. Before I could get it home it seized up completely to the point it was like doing a brake stand each time you tried to get rolling and was smoking hot.
If you're fairly good mechanically Nissan sells a caliper rebuild kit for about $40 that will do both rear (non brembo) calipers with new piston bore seals, outer water seals and a special grease for the piston seals. You'll also want to service the caliper slide pins while they're out and grease them up with the stuff provided in the kit for them as well.
Upon disassembling my calipers it was clear the pistons and bores were all corroded up from water getting in after the outer piston seals had cracked. Rebuilding both of them start to finish didn't take more then a few hours and then I spent the money saved on new rotors and pads since the ones on the stuck wheel were completely toast.

 

I have the same problem on my Z. I was doing a search hoping to find an answer. I have replaced my left rear caliper and I still have the same problem. I had my brakes inspected and the mechanic said they are working correctly, including the parking brake. So, are there any other possibilities as to what is causing this heat? My Z is an 08' Enthusiast with 47K miles.

 

The slider pins can also cause this.

 

I replaced the pins and used new lube as well. I've had the car for just under a year and this is my first issue with it. Replacing the caliper is the extent of my ability. Now I'm just scratching my head and hoping I don't have to take it to the dealership. $$$

 

This is highly unlikely but you may want to pull the rotor and inspect the e-brake pads, actuator and springs. Because they are drum type they self-actuate once applied to the drum surface. If the springs that pull the pad away from the surface are damaged or broken they may be applying pressure unintentionally. To remove the rotor you'll have to not have the e-brake engaged.

Once you put it back together you’ll want to adjust your e-brake engagement point. You’ll notice a small hole (probably with a rubber grommet plugging it) that is on the surface that meets with the wheel hub. Align that to the actuator adjustment screw inside the e-brake assembly and use a screw driver to move the e-brake pads towards or away from the brake hub surface. You’ll notice a change in the hand brake feel as you do this. Be sure to inspect and adjust both rear brakes.

 

I took it to the dealership today and they called around lunch time to let me know I needed to replace the caliper (even though I already did this on Saturday) and their recommendation was to replace both calipers, new pads, and resurface both rotors. They had all parts in stock and wanted
$800+ to complete it. I don't have that kind of $$ right now. I've already replaced the caliper. I guess I'll start replacing one part at a time until I find out where the problem is. Wish me luck!

 

Was waiting for an update, was actually thinking bearing maybe.

 

Any updates?
MY Car just had new brakes and rotors installed. I had brought the car to body shop to get a bumper repaired and resprayed. It sat for 2 weeks.
I pick it up and the first thing i noticed with a click click click sound when driving. The faster i went the car started feeling sluggish. When I pulled over thinking I had a flat or something I feel a crazy amount of heat coming out of rear passenger wheel well..