Why do I smell burnt hair when I drive?

General Discussion
,
1

I have a 1998 Merc Mystique. Great car. Under 100,000. Drives nice. But, when I drive I always smell burnt hair! Recently replaced all 4 brakes and an oil change. Still, burnt hair. Engine temp stays neutral. Car behaves normally. I am at a total loss.

2

There could be a dead rodent in the engine compartment. A small oil leak burning off can produce a whole lot of stink

1 Like
3

There might be a problem with the new brakes IF the burning hair started right after they were changed.

To test this… After driving the car to the point you smell burnt hair, stop and check how warm each wheel is. Be careful, they might be really hot. If you find any that are significantly hotter than the others, you have a sticking caliper. If you have two that are hot, it might be a bad master cylinder. Either needs to be fixed right away.

1 Like
4

Additionally, check the wheel temperature with an infrared thermometer or a meat thermometer. The IR unit is more accurate, but you are really looking for a difference in temperatures. The meat thermometer should be accurate enough for that.

5

Check to see if a plastic bag melted onto your exhaust system. the smell will last for a while.

6

You might try some experiments to narrow the odor-causing culprit down.

  • Do you notice it outside your idling car?
  • If noticed outside of idling car, is it worse from the engine compartment, or elsewhere?
  • Do you notice it inside your idling (vs driven) car?
  • Do you notice it more or less with A/C on vs off?
  • Do you notice it more or less with heater on vs off?

I expect you already know that just b/c it smells like burning hair, it might not actually be burning hair, could be something else. If it is burning hair, my first guess is a rodent has made its way and died in the hvac blower-motor cage area.