2000 Honda Accord smells like burning rubber when climbing a hill at highway speeds

[TurboTravis]

Hey guys,

I have a 2000 Honda Accord (4 cylinder) with 395000 miles. I replaced the engine at 290000 with a used serviceable unit. It has done this for awhile and I cannot find the source...

It produces a noticeable burning rubber smell when climbing a significant hill at highway speeds. It's more noticeable with the windows down. All of the obvious stuff can be eliminated (belts rubbing on something, tires rubbing on something, etc). It's not being caused by any external friction source, and there are no oil leaks. I've even tried extending the exhaust exit past the bumper. There are no exhaust leaks. I've tried removing the valve cover vent from the air intake tube and venting it externally with a long hose that dumped about mid-chassis. I recently removed the dipstick and capped it off with a piece of rubber and a bolt (thinking that excess crankcase pressure was exiting past the loose fitting stick). I think that helped reduce the odor but it could be placebo. Any ideas?

-Travis
...............

 

[brianl703]

Have you tried checking for a build-up of road debris on the top of your muffler or other parts of the exhaust which could be heating up and causing the smell when the engine is under a heavy load for long enough?

Road debris contains a LOT of rubber, from tires. This will smell when it gets hot.

A similar thing is known to happen with the Chevy Volt when it's run in mountain mode and the engine is running hard to charge the battery up. (The Chevy Volt needs to have a sufficient charge in the battery to go up a significant grade at Interstate speeds, because the gas engine isn't powerful enough to do it by itself, so it needs both the electric and gas motors. Mountain mode ensures that there is sufficient charge.)

 

[dishdude]

Car has so much power you're roasting the tires and don't even realize it.

 

[HowAboutThis]

How much oil does it use? Leaking somewhere under heavy load?

 

[2009Caraman]

I will bet money it is a sticking rear caliper. Get the symptoms to surface then quickly pull over and smell behind the tires.

Edit. The burning smell is likely the pads not the tires. It only happens uphill because gravity pushes brake fluid back. This happened to me. It took me a year to figure it out.

 

[OilUzer]

Other possibilities:
Maybe seeping oil or trans fluid burning and noticeable when things get hotter going uphill.
Or hot or burning trans fluid with TC unlocked going uphill.

is it manual or auto?
Clutch burning smell?

 

[10WSmuckers]

Check your trans fluid. Do you stay in a certain gear for a long time when going uphill?

 

[partspro]

Slipping belts at the higher rpms maybe ??

 

[TurboTravis]

Have you tried checking for a build-up of road debris on the top of your muffler or other parts of the exhaust which could be heating up and causing the smell when the engine is under a heavy load for long enough?

Road debris contains a LOT of rubber, from tires. This will smell when it gets hot.

A similar thing is known to happen with the Chevy Volt when it's run in mountain mode and the engine is running hard to charge the battery up. (The Chevy Volt needs to have a sufficient charge in the battery to go up a significant grade at Interstate speeds, because the gas engine isn't powerful enough to do it by itself, so it needs both the electric and gas motors. Mountain mode ensures that there is sufficient charge.)

I will inspect the top of the muffler-thanks for the suggestion!

 

[TurboTravis]

I will bet money it is a sticking rear caliper. Get the symptoms to surface then quickly pull over and smell behind the tires.

Edit. The burning smell is likely the pads not the tires. It only happens uphill because gravity pushes brake fluid back. This happened to me. It took me a year to figure it out.

Very interesting-I will look into this.

 

[TurboTravis]

Check your trans fluid. Do you stay in a certain gear for a long time when going uphill?

I've kept the trans (auto) properly serviced. It does not leak or use any fluid or show signs of excess heat or wear material.

 

[circuitsmith]

Are there any missing exhaust heat shields?