These don't seem to be major problems but they're making me curious and the second problem is the worst.

My truck is: 2004 F150 Lariat 4x4 with 5.4 V8 and 3.73 limited slip rear end.

1. I thought I smelled an electrical burn or coolant smell a few times when starting the truck. Oh and before I go any further, my truck sits outside all work with the front tilted slightly (just barely) down hill because of the way my driveway is. I usually only drive the truck a time or two on the weekend now. Ok, so I thought I smelled something so the next couple times I started it, I looked under the truck immediately after starting and I see a light mist or sort of smoke coming from the passenger side, rear of the engine just to the right of the exhaust. I thought then it must be coolant burning off. I see no leaks, the oil looks good and the coolant is not getting lower. My thought on this is it just got rain on the engine somehow and that water was steaming off when I started the truck? I haven't seen this the last few times I started the truck. Looks ok right now, but what are your thoughts? The most weird thing is that NOW the last few times I've started the truck (in the morning, not having driven it anywhere), I saw a short burst of liquid drip out. It was a small stream at first then quickly went to a small drip, then nothing. It looks like water. Is this coming from the heater core box or something? Just flushing out some extra moisture and it's no problem?

2. This is the one that's really driving me nuts. It seems to have happened pretty suddenly because I noticed it one day when driving and it doesn't seem like it's been getting progressively worse. I just noticed it one day. Here's the problem. When I'm driving, it feels like there's something constantly holding me back as if I'm riding the brakes. My gas mileage has gone down close to 2 MPG now (used to average around 15 MPG, now I'm getting more like 13 MPG average). In the past when I was on the highway on a flat stretch, I could let off the gas and it would coast nicely. Now, it feels like it almost immediately starts slowing down when I let off the gas. When I'm driving, I have to keep my foot on the gas and constantly keep it going or it'll start slowing and not coast like it used to. Even going down slight declines/hills, it slows down a little when letting off the gas. It's nothing extreme, but it's noticeable and driving me crazy. I had recently replaced both front brake rotors since they were sticking (happened before this problem) so I don't think it's a brake issue. I also put my hand on all the rotors after driving on the highway and none of them feel hot. They're just barely warm - normal. I even felt the rear end and it feels just a tiny bit warm but nothing unusual as far as I can tell. It doesn't feel like it's stuck in 4 wheel drive either - the steering is normal, turning is normal (you can feel it when it's in 4 wheel drive and it does not feel like it's in 4 wheel drive). Early this year I had the fluid in the front and rear differentials changed at the dealer.

So that's the scoop. Any ideas?...especially on that 2nd one. I'm going to take the truck to a trusted privately run repair shop and see if he can find anything obvious (obvious to him anyway) but if he doesn't see anything, I'm not sure what to do other than just keep driving it with the crappy mileage and wait for something to break or start smoking. I kinda hate to drive it on any long trips though since I feel like there's something really odd going on with it now and I don't know if it'll break down at some point because of whatever is going on. Oh and it has 133,000 miles on it now. Engine runs perfect. Transmission seems perfect.

 

1. You first question is actually two questions! ...the first part , I don't know. The second, (before the **** stars start in) was that coming out of the tail pipe? If so, probably just condensation (water), and normal.
2. Some owners have had the parking brake drag or seize, and that may be what the issue is. The parking brake is a drum system on the inside of the rear discs- you can't see it unless it is disassembled/removed from the truck. It might or might not be hot after driving depending on how bad it's dragging (if that IS the problem).

 

1. It's coming from under the engine. To the rear of the engine, right around where the tube that you see that I think is coming from the transmission. It's sort of in the area right below where I know that drain tube is that comes from the heater core box up higher. But basically it's right next to the engine, to the rear on the passenger side.

2. It's not the parking brake. I know they are drum brakes (for the parking brake) and I put my hand on that portion of the rotor/drum combo right after driving and it's cool. If it was dragging at all it would be very warm or hot.

 

#1....it could be your ac pan drain.....idk?

#2.....winter blend gas will cause a reduction in mpgs....

 

It's not the usual winter time reduction in mileage that I'm noticing and used to...it literally feels like something is holding me back and I have to give me more pedal than I used to. On a flat back road where I can do 50 MPH, I had to BARELY touch the pedal in the past...but now, it feels like I'm being held back and have to give it more gas to keep going.