I have a 2004 F-150 Lariat supercrew. It has only 11,000 mi on it. Tonight after driving 20 miles, I pulled into my driveway and suddendly the cab filled with a strong smell of burning rubber. Smelled like a vacuum cleaner drive belt burning up. I went to the front of the truck and noticed some faint white smoke coming out from the right headlight area. I immeidately opened the hood, but could not see any visible smoke...but did get a strong smell of burning (rubber or plastic).

I turned off the truck and touched the main belt, and it was not hot at all. I reached in and touched the compressor flywheel, and it was extremely hot. I looked for other belts, any wires that may have come loose and made contact with hot engine components...but found nothing.

I started the truck back up and at idle not a real bad smell. So, I took it out for a quick ride, and sure enough, the cab filled with the smell. I left the truck running and went around to find where the smell was strongest...and found it to be in the right front wheel well. I looked everywhere for signs of smoke or anything....but could not see anything. Did notice that at idle the smell was barely there, but when rev'd up, smell came back strong.

Has anyone had this happen to thier truck? Any suggestions on what it could be...how to fix it? Affriad to drive it....are there other belts that I cannot see?

 

Sounds like the compressor pulley is either binding or seized completely and the belt is just sliding around it. If that's the case it's only a matter of time before the belt breaks and leaves you stranded. There's just the one belt that drives all the components so your problem is definitely there somewhere.

 

Hi Tbird69, thank you for your reply.

I am not very mechanical. But when I ran the truck tonight I did not have the air on at all (in off position). After I got home and was checking for the cause, I did turn on the air and noticied that the compressor did "click" on, and at that point the center of the pully did spin....and cold clean, fresh smelling air was coming thru the vents.

Could the compressor pully be frozen only when the system is off? Would the Air conditioning be working if the pully was frozen or hung up?

The smell is strongest in the right wheel well and the compressor is right there on that side....and it was very, very hot to the touch, while the belt was much cooler. Is there a definitive way for me to test to see if the pully is frozen?

 

The A/C wouldn't be working if the pulley was frozen. It's designed to "freewheel" when the system is off so the belt can continue to drive the other accessories. It's odd that the A/C pulley got so hot in the first place. Personally I would pull the belt off and check all the pulleys to make sure everything is turning properly.

 

Have you ever replaced the headlight bulbs? Maybe it could be the bulb melting the housing?? Just a Idea??

 

Also, look for any pieces of plastic that may have come loose and dropped down into a "hot" area of the engine compartment. When I bring home a new vehicle, I scour the engine compartment for little plastic protective caps and covers that are likely on certain assemblies when they're installed.

My wife's new Escape had a at least 4 or 5 of these things laying loosely in the engine compartment when I brought it home, and if I remember correctly, I found 1 or 2 in my new F-150 as well. I suspect that most just drop onto the floor of the assembly plant, but some apparently fall off into the nooks and crannies of the engine compartment.

If one rattled loose and fell down into an exhaust manifold, it could cause a distinct burning smell until it eventually melted away to nothing. Just an idea.......

 

Try the blower motor or the heater resistor.

 

My wife's 'yota had a similar problem. I took it to the dealer, and it turned out that one of those plastic grocery bags had gotten itself wrapped around the exhaust system somehow. After a couple times driving it, it melted away, no more smell!