Intermittent burning smell?

[RyanRR]

Since you smell it outside sometimes, my guess is that it is not the HVAC and it’s something under the hood. The HVAC draws air from just below the windshield, so if you have some fumes coming up from under the hood, they can get sucked into the cabin when the HVAC is on, but the smell will be reduced when the HVAC is off. If the problem was in the HVAC itself, I don’t think there is any way you’d smell it outside the car.

You mention that you checked the manifolds and don’t see anything. I’m not sure how you are checking, they appear to be completely shielded on my car - I can’t see any part of the exhaust manifold itself, and its pretty tough to get a look all along that lower edge of the valve cover as well. Might be able to see with a borescope. Valve cover leaks seem to be pretty common in these cars, and generally don’t leak enough to change the oil level (just a seep) until they get pretty bad.

The other thing that occurs to me is a slipping belt, which can cause a burning smell.

The slipping belt is interesting, next time I smell it I'll see if I can pinpoint the location better or determine if it's a rubbery smell. I was poking around looking at the exhaust and everything when I had it up on the lift (benefit of having access to the public works garage!) and I did the best I could to look for leaks or signs of burning/burnt oil.

I’ve smelled burning PS fluid or Transmission fluid (hydraulic type smell) once or twice, usually on long interstate trips once I get off on an exit. Transmission states it will vent excess fluid and it happens to drip on the exhaust.

I'll check that a bit closer next time I get underneath it, the exhaust pipes all looked clean (minus the occasional small spot of rust)

 

[Greggnvt]

Our 2013 LR4 had a leaky valve cover, driver side. There were actually some drips on the garage floor but really only noticed it when coming off the highway and sometimes you would even see some "wisp" of smoke coming from under the left front fender. If not a fluid leak, could it be the brakes?

 

[MDJ2015]

Vehicle:
2013 LR4
124,800 miles


I've put 10k on my LR4 since I bought it in October of last year, it spends 95% of it's life cruising @ 70-75 mph.

In the past 2-3 months, I've noticed an issue where I get a somewhat strong odor of something burning from the front end, and I notice it most easily when I have my heat on. Turn the heat off and the smell goes 90% away, but I can still smell it even after parking. Next morning the smell is gone from the garage, and I don't smell anything after starting it up and driving to work (45 minute commute each way).

Initially I thought it may have been the odor of coolant, but after a few moments I realized it didn't have that distinct burning coolant smell. Coolant levels are fine, and my oil looks fine when I changed it a couple weeks ago.

I've probably experienced the smell 3-4 times in those 2-3 months. Each time I had the heat on somewhere between 65-72*.

I can't see any leaking fluids anywhere in the engine bay or underneath. I have newer rotors and pads and nothing looks oddly worn (dragging brakes, etc), and it doesn't really smell like brakes anyway.

I'm at a loss as to where I should be looking next, any suggestions would be great!

I had a very similar problem. It was inconsistent and the dealer couldn’t replicate it. One day I noticed wisp of smoke from the A pillar. I had replaced my windshield a year or two earlier and some wiring in the A pillar was messed up. I was able to get it fixed cheaply.

 

[Frank8]

When my 2016 LR4 was new it had intermittently sticking front brake pads - the pistons would freeze and the pads and rotors got smelly hot. It was intermittent and sometimes didn't last long but I could smell it especially if the heater was on. It also stank up my garage with a sort of burning smell.

You might check to see if the rotors are hot the next time you smell it. It's a characteristic brake odor - not like oil or coolant.

Frank

 

[skiwpk]

I have the same smell. Burning but not oil related. Replaced passenger side valve cover and power washed the engine to remove residual oil (thought the burning was oil), but that didn’t solve it. My mechanic suggested it was the cabin air filter burning, but I haven’t had a chance to confirm.

 

[puckball55]

Since you smell it outside sometimes, my guess is that it is not the HVAC and it’s something under the hood. The HVAC draws air from just below the windshield, so if you have some fumes coming up from under the hood, they can get sucked into the cabin when the HVAC is on, but the smell will be reduced when the HVAC is off. If the problem was in the HVAC itself, I don’t think there is any way you’d smell it outside the car.

You mention that you checked the manifolds and don’t see anything. I’m not sure how you are checking, they appear to be completely shielded on my car - I can’t see any part of the exhaust manifold itself, and its pretty tough to get a look all along that lower edge of the valve cover as well. Might be able to see with a borescope. Valve cover leaks seem to be pretty common in these cars, and generally don’t leak enough to change the oil level (just a seep) until they get pretty bad.

The other thing that occurs to me is a slipping belt, which can cause a burning smell.

i just had my valve cover gaskets replaced . i have 2013 with 96k miles on it.i started by noticing small. stains on my driveway. i crawled underneath and found one drip but it didnt really look or feel like oil

 

[jlglr4]

My mechanic suggested it was the cabin air filter burning

That‘s a new one to me. Did he suggest how the cabin air filter could possibly be burning? The only thing I’ve ever heard of burning up in the hvac is the blower motor, more specifically, the bearings in the motor. That can cause a terrible smell.

 

[Aboshi]

So I just had this same issue and fixed it. I take it your smell is almost like antifreeze smell but instead of being sweet it smells bitter like plastic or some other really bitter smell mixed in?

Here’s what it came down to:
I already changed the cross coolant pipe so you can check that one off.
Next the tensioner pulley bearing exploded, so replaced the tensioner and new belt (huge pain in the @ss to get the belt over the water pump pulley). I only noticed the smell after I heard my fan clutch going. Start the car cold and hear the thuuup tuuup thuuup a few times, and then it goes away. Sometimes it won’t make the noise at all. Anyway it turns out it’s the fan clutch making that horrid smell. The clutch burns out and most likely starts burning up the electronics inside as well. So you’ll get the smell while the car is under load but after you park the smell goes away in 20-30 mins.

 

[RyanRR]

I had a very similar problem. It was inconsistent and the dealer couldn’t replicate it. One day I noticed wisp of smoke from the A pillar. I had replaced my windshield a year or two earlier and some wiring in the A pillar was messed up. I was able to get it fixed cheaply.

Mine does have a new windshield, installed immediately before I bought it, I'll check that!

When my 2016 LR4 was new it had intermittently sticking front brake pads - the pistons would freeze and the pads and rotors got smelly hot. It was intermittent and sometimes didn't last long but I could smell it especially if the heater was on. It also stank up my garage with a sort of burning smell.

You might check to see if the rotors are hot the next time you smell it. It's a characteristic brake odor - not like oil or coolant.

Frank

I just installed new brake pads and rotors about 5k miles ago, including greasing up the pins and cleaning them up really well. I haven't noticed any wear marks or other indicators of brake issues.

So I just had this same issue and fixed it. I take it your smell is almost like antifreeze smell but instead of being sweet it smells bitter like plastic or some other really bitter smell mixed in?

Here’s what it came down to:
I already changed the cross coolant pipe so you can check that one off.
Next the tensioner pulley bearing exploded, so replaced the tensioner and new belt (huge pain in the @ss to get the belt over the water pump pulley). I only noticed the smell after I heard my fan clutch going. Start the car cold and hear the thuuup tuuup thuuup a few times, and then it goes away. Sometimes it won’t make the noise at all. Anyway it turns out it’s the fan clutch making that horrid smell. The clutch burns out and most likely starts burning up the electronics inside as well. So you’ll get the smell while the car is under load but after you park the smell goes away in 20-30 mins.

That could definitely be it, you nailed the smell as well! I'll start poking around and see what I can find in there

 

[skiwpk]

So I just had this same issue and fixed it. I take it your smell is almost like antifreeze smell but instead of being sweet it smells bitter like plastic or some other really bitter smell mixed in?

Here’s what it came down to:
I already changed the cross coolant pipe so you can check that one off.
Next the tensioner pulley bearing exploded, so replaced the tensioner and new belt (huge pain in the @ss to get the belt over the water pump pulley). I only noticed the smell after I heard my fan clutch going. Start the car cold and hear the thuuup tuuup thuuup a few times, and then it goes away. Sometimes it won’t make the noise at all. Anyway it turns out it’s the fan clutch making that horrid smell. The clutch burns out and most likely starts burning up the electronics inside as well. So you’ll get the smell while the car is under load but after you park the smell goes away in 20-30 mins.

This sure describes my issue. The type of smell and when I smell it. Challenge is I had the fan clutch replaced a month ago and I’m still getting the same smell. Wonder if the fried fan clutch fried something else.