what could it be....?

Question

after about a few minutes, maybe more, of driving my truck there is a burning rubber smell and some smoke. yet when i opened the hood and restarted the engine it does nothing. it's like it doesn't want to do it if i'm staring at it. we just got the serpentine belt done about june/july. my sister's boyfriend thinks it might be motor oil spilled on the hot parts of the engine. i just don't want to have my truck blow up on me because i love my little truck.

Answer 1

it could be a belt that jumped (flipped over) and is slipping when you step on the gas and it would smell like burnt rubber. TRY THIS: Put the car in park and you give the car gas while SOMEONE else looks under the hood, then maybe you might catch where the smoke is coming from. Just a thought..

Answer 2

although there is a defitive difference between the smell of oil and the smell of rubber....your sisters boyfriend may be correct...look around the valve covers and on the exhaust to see if it looks like oil has leaked. Oil can also leak from the intake manifold...normally in the fron or rear of the intake and that will run down and get on your exhaust and make some smoke...it may be that it only leaks a little and thus it goes away after a few minutes. If it was a belt one would think you would be able to see it and it would do it all the time...also the belt would squeal if it was doing this...in most cases...and you say you just replaced it so that is most likely not the problem, Also...look at your wiring and be sure there is not any wires laying on something hot and burning.

Answer 3

This is a case when you have loaded more than required Engine Oil. When the truck is cool it might not be causing trouble to you. However, when the engine is heated up after a few miles of distance, the oil spils over.
The second possibility which you might be facing after a few miles is that your truck starts mis-firing due to faulty bore which permits your engine oil to reach out and hence throwing up smoke.

Answer 4

Good Question...and Wise of You to be concerned.
"mystery symptoms" are difficult to troubleshoot,,especially when they appear intermittently,or at random.

Your Sis's boyfriend had a good idea about Spilled Oil.
But USUALLY the smoke and smell from that will PERSIST for several minutes,,,long enough to stop>open hood>and see/smell.

MOST actual "underhood" conditions generally follow that scenario---they'll tend to last a few minutes,,long enough to see.

If You are confident in your ability to distinguish a Burning Rubber Smell from a Burning Oil Smell(not always so easy--but distinctly different),,,then it's a matter of determining the Possibilities of "What COULD it be?"

Really about the "Only Rubber" underhood is Fan Belts.
****BE CAREFUL When Engine is Running and You have the hood open!!!*****
Parts can come flying out,,,such as shredded FanBelt particles.

Try Running the engine a while with Hood OPEN to allow most the Heat OUT.
Then STOP the engine and Feel the fanbelts,,,they'll Be HOT,,but not "blistering hot".

Their appearance should be a sorta dull/matte look.
I mean on the contact surface area that drives them,,not the un-touched back.
Serpentine belts usually have contact on BOTH sides,,Inner and Outer Diamters.
V-Belts contact on each side.
If they look Glassy/Shiny/Glazed thats often an indication they're Slipping,,and overheating from the Friction.

Double check the "new" serpentine belt for any wear at it's EDGE/side,,,and also for any cracking in each individual ridge.
They will sometimes try to crawl in/out of proper place on their pulleys.

It's a Tuff Judgement,,,but the Pulleys and any Rollers/Idlers which contact the belts will be Shiny and "clean",,but they should NOT look GLASSY/Chromey/ Mirror-like/or otherwise POLISHED.
That indicates Slippage= Heat=Smoke & Smell.

Ya can look also for "rubber dust" around the belts' path,,pulleys,etc,,,,again it's judgement.
a little is Normal,,but very much is Not.

Another possibilty,,,there's a variety of Plastic Panels and covers and shrouds,etc.
The Mountings crack,bolts fall out,or they get damaged,or sometimes improperly Re-installed after servicing.
Make sure none of those panels have come loose and are Intermittently Rubbing on a Moving Part(Like Belt/Pully),,,
OR,,not touching a Hot area like Exhaust.

Realize too that such a prob MIGHT NOT happen while Parked.
The WIND from Driving down the road can push a loose panel into a Hot Exhaust for example,,,then when You stop to Look,,it's "springiness" returns it to an OK-looking position.
All LOOKS fine at a glance,,,till ya take off down the road again and the Wind pushes it back to the hot /burning position.

So if ya can SEE any plastic panels,,use a flashlight or something and make sure there's no burned-spots.
Especially if it's anywhere Near the exhaust system.
You can even push/pull on them to see if they're mounted solid.
Use something like a broom handle to Carefully Push/Pry the panels to see if they're loose or attatched well.


Oil can smell like Rubber,,very close.
Again,,WIND can push any leaked oil to a Hot Place,,,which wont happen while Parked.
Tricky to Find,,cuz even a Tiny bit of oil can make a BIG stink with lottsa smoke,
Then it burns off and is gone,,,and hard to find the source.

Auto Transmission Fluid CAN smell a lot more "plastic" than engine oil.
Sometimes it will foam at driving speeds and some will come out and find a place to get hot and burn.

If you have an Automatic Transmission,,,1st thing is to make sure it's NOT Overfilled.
And the fluid is so clear/light,,it can be tuff to See Leaks,,,so LOOK CLOSELY.

Look around the Radiator Fan area.
Some Fans are surrounded by Shrouds which have a sorta Flaps on them,,almost like Curtains or Blinds.
Under certain conditions those flaps blow open to allow airflow,,normally they're closed simply by gravity or their own "springiness".
It's POSSIBLE that one could be loose and intermittently contacting a Hot area,,or rubbing on a belt,etc.
You may not necessarily HEAR any possible Rubbing sound,,if it's happening.

Smoke and Smell from underhood comes down to 3 basic things
1)Fluid Leaking on a Hot Part
2)Belts slipping and Overheating
3)A Part touching a Hot Area that it should not be

-Try turning Steering wheel back & forth,,maybe squirting Steering Fluid intermittently?
-Try With AirConditiong On and Off,,maybe A/C Belt slipping?
- Try Driving in a "Safe" place,,where ya drive till it smokes then Immediately Stop SAFELY and open hood and Look??
-The entire exhaust system starting at the engine--the Exh manifold itself--should be DRY looking and consistent in it's coloration/appearance.
If You see any Dark Spots especially,,or any unusual looking spots or splotches,,,thats suspect to be caused by a Fluid Leak,,or something touched & burned there.

One other thing---not as unusual as it may seem--is "Road Debris".
Mostly,, Plastic Bags.
They can get stuck under a car,,and intermittently Contact the exhaust or something hot.
The Smell is USUALLY persistent,,and there's Usually NO visible Smoke.
But it's worth checking,to eliminate that possibility.
The Actual Item may be Long Gone,,,but it can leave a patch of material stuck to the exhaust which takes a long time to burn off.

Plastic itself can be weird when melted on a hot surface.
It initially will be very volatile,,a relative Low temp will burn it and make smoke & fumes.
Then the longer it burns,,,the HIGHER the temp required to make it smoke and fume.
I've seen SEVERAL times where a blob of plastic had burned to just "charcoal",,and remain stuck to exhaust but INERT--No More Smoke/Fumes.

One Odd effect of that property is that HIWAY speeds can raise the exhaust temp Hi enough to make the plastic smoke & burn.
Idle speeds while parked in the driveway MAY not create High enough temps to further Burn the increasingly crispy plastic.
So the Burning Smell is intermittent,,,it comes and goes with Driving conditions,,,even though it's same blob of plastic stuck to same spot.
Sounds Crazy,,,doesnt happen often,,,but it DOES happen.
And VERY tuff to find without careful inspection.

If You cannot find the Prob,,,DEFINITELY take it to a reputable Shop.

It's Not doing that "for no reason".
And the actual Problem can just as easily be something Silly/Simple/Harmless as it can be VERY DANGEROUS,,even Disastrous.
And it can cause EXPENSIVE further damage.

Above ALL ELSE,,BE CAREFUL poking around under the hood or even when looking Under the truck.
Especially if you have the engine running.

Dont just "hope the prob goes away" even if it seems to go away.
Your safety and Your Lil' Truck's safety is important enough to find out for Certain what the cause is.

Good Luck!

Answer 5

You may also want to have your brakes checked. Could be that the brake pads are dragging against the rotors.

Answer 6

it could be oil or gas on the spark plugs. change the spark plugs and that should solve the problem.