Burning Rubber Smell in the Cabin...?

I had this same smell on my 2016 EB, but it did not start until the car had around 32k miles.

My 2016 GT PP has 6,200 miles on it and since I bought it, I periodically get a burning rubber smell inside the cabin. Smells a lot like cooked tires or a rubber hose / belt.

No signs in the engine bay of any hoses or belts failing or bad tensioners etc. Anyone have this and any ideas where's it's coming from? I usually only smell it when I'm sitting at a traffic lite. Doesn't matter weather I have the vents set to hot or cold, so I'm thinking it's coming from the engine compartment or possibly the blower fan.

If this is a common issue that can be addressed rather easily I'd rather take it in knowing the cause if possible. Thanks.

I had this issue come up this week on my GT PP when stopped at a light or idle first thing in the morning. First dealer couldn't find anything but did find my rear diff was leaking. They mentioned my brakes might have oil on them and be contaminated (I had the car rustproofed with an oil spray a few months ago).

Second dealer was fantastic and found that the AC compressor was seized and that belt was causing the burning smell. Replaced AC compressor and belt and 90% of the smell went away, but when I got out of my car after a drive I could still smell a whiff of it. No smell at all while idling. I also tried to not use my brakes for a while before parking (downshift braking and taking a route that allowed for it) and the smell was not present at all, so I think my brakes need to be cleaned as well.

I'm going to try and clean my brake pads and rotors this weekend and see if that effects anything.

Also check your cat convertors, make sure no bags are melted on them etc.

TheLion said:

I had this same smell on my 2016 EB, but it did not start until the car had around 32k miles.

My 2016 GT PP has 6,200 miles on it and since I bought it, I periodically get a burning rubber smell inside the cabin. Smells a lot like cooked tires or a rubber hose / belt.

No signs in the engine bay of any hoses or belts failing or bad tensioners etc. Anyone have this and any ideas where's it's coming from? I usually only smell it when I'm sitting at a traffic lite. Doesn't matter weather I have the vents set to hot or cold, so I'm thinking it's coming from the engine compartment or possibly the blower fan.

If this is a common issue that can be addressed rather easily I'd rather take it in knowing the cause if possible. Thanks.

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I had these same symptoms, I had an oil leak from the valve cover dripping on the headers. Mine was a V8, it would be interesting if it is happening on the ecoboost too... look for signs of oil dripping onto something hot

cechk01 said:

I had these same symptoms, I had an oil leak from the valve cover dripping on the headers. Mine was a V8, it would be interesting if it is happening on the ecoboost too... look for signs of oil dripping onto something hot

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I've read a few on leaking valve covers, it's fairly common failure mode for valve cover seals. Every V6 or V8 've ever owned has at some point started to leak from the valve cover lol. Even one 4 cylinder did (mazda MX-5, but to their credit it was 12 years old).

It doesn't smell like burning oil. Typically leaking oil will smell like burning oil, very distinct. This smells like burning rubber which has me a bit baffled but I'll double check all the seals for leaks in the engine bay. What I found so strange is that this exact smell started up in my Ecoboost the last 6k miles before it got traded in for this amazingly beautiful and fast GT (which I should have bought in the first place lol).

It could be some rubber or rubberized plastic part getting hot, maybe by the exhaust / fire wall I'm thinking. Both the 2.3 EB and the 5.0 V8 have exhaust headers that run on the passenger side. I'll take a good second look over the whole car once I get a chance and report back.

TheLion said:

I've read a few on leaking valve covers, it's fairly common failure mode for valve cover seals. Every V6 or V8 've ever owned has at some point started to leak from the valve cover lol. Even one 4 cylinder did (mazda MX-5, but to their credit it was 12 years old).

It doesn't smell like burning oil. Typically leaking oil will smell like burning oil, very distinct. This smells like burning rubber which has me a bit baffled but I'll double check all the seals for leaks in the engine bay. What I found so strange is that this exact smell started up in my Ecoboost the last 6k miles before it got traded in for this amazingly beautiful and fast GT (which I should have bought in the first place lol).

It could be some rubber or rubberized plastic part getting hot, maybe by the exhaust / fire wall I'm thinking. Both the 2.3 EB and the 5.0 V8 have exhaust headers that run on the passenger side. I'll take a good second look over the whole car once I get a chance and report back.

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What about belts? Do they feel warm after driving?

I've noticed this smell too on occasion. Interested to see what you find.

I've also read that if you run synthetic oil when it burns it smells like rubber.

cechk01 said:

I had these same symptoms, I had an oil leak from the valve cover dripping on the headers. Mine was a V8, it would be interesting if it is happening on the ecoboost too... look for signs of oil dripping onto something hot

Click to expand...

TheLion said:

I've read a few on leaking valve covers, it's fairly common failure mode for valve cover seals. Every V6 or V8 've ever owned has at some point started to leak from the valve cover lol. Even one 4 cylinder did (mazda MX-5, but to their credit it was 12 years old).

It doesn't smell like burning oil. Typically leaking oil will smell like burning oil, very distinct. This smells like burning rubber which has me a bit baffled but I'll double check all the seals for leaks in the engine bay. What I found so strange is that this exact smell started up in my Ecoboost the last 6k miles before it got traded in for this amazingly beautiful and fast GT (which I should have bought in the first place lol).

It could be some rubber or rubberized plastic part getting hot, maybe by the exhaust / fire wall I'm thinking. Both the 2.3 EB and the 5.0 V8 have exhaust headers that run on the passenger side. I'll take a good second look over the whole car once I get a chance and report back.

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k4show said:

I've also read that if you run synthetic oil when it burns it smells like rubber.

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So I took a look today and this is the only thing in the engine bay that showed any moisture/fluid. Passenger side bolt closest to the front (cam shaft bolt I believe?) had a small amount of fluid gathered around the base of the bolt. If you look near the 7 or 8 o'clock position around the bolt you can see it. Sorry for the low light phone pic.

Didn't see anything under that from where it had dripped on but if it did end up on the passenger side header it could be my smell as I'm running synthetic oil.

What do you think?

Added a circle around the fluid. I did clean some of it up before thinking of taking a pic. There was more around the entire bottom section when I first found it.

TheLion said:

I've read a few on leaking valve covers, it's fairly common failure mode for valve cover seals.

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Ford? Leaking valve cover gaskets? Never (this is the fourth Ford I've owned...so far none on mine that I can verify...although I had a very leaky timing chain cover!).

master fluid leak?

ElAviator72 said:

Ford? Leaking valve cover gaskets? Never (this is the fourth Ford I've owned...so far none on mine that I can verify...although I had a very leaky timing chain cover!).

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Oh it's not just a Ford thing, it's an every car thing. My 2001 Chevy Impala 9C1 Police Interceptor I drove during college (push bars and spot light included) had very leaky valve covers. Replaced the seals and within 50k miles they were leaking again, just a bad design as the compression on the o-ring wasn't very good so once they started to dry up they would leak).

My fiance's 2003 Honda Civic with 250k miles leaked like a siv and it had the seals replaced a few times and that's an up-right in line 4 cylinder. V-6 and V-8's are more prone because the covers are at an angle and fluids sit there for longer periods of time comparatively.

But that makes sense, I could not find any signs of a hose or wire keeper (plastic ribbed tubing) that looked to be cooked. Only a very small amount of moisture / oil collected in the same area as above, so that's probably it.

Gonna take it into the dealer and point them in that area as it's pretty strong smell and is very frequent on mine. Sure it has 8 quarts of oil and it's not a reliability concern at this point as it's quite a small amount comparatively, but it shouldn't be leaking at only 7k miles on the clock....that's a warranty fix. Engine is bone stock so I don't expect any gripes from the dealer at this point.

No, I'm still running the Motorcraft semi-synthetic blend until it's due for a change. Dealer changed the factory fill at 5k6 miles with 16% left on the oil life indicator (they forgot to reset it). I figured I would do the same break in process as I did on my Ecoboost (which made more power to the wheels than any other FP tuned setup I've seen so far). Run the factory oil for first 10k to wear in the bearing surfaces then switch over to a higher quality oil, in this case the really good Penzoil Ultra Platinum. If it's good enough for a 650 HP Viper ACR, Challenger Hell Cat etc. it's good enough for my Coyote 5.0! And now I don't have to worry about LSPI affects since i'm NA and lower BMEP.

Got the car back, no luck on finding any leaks. Dry as a bone. They suggested it may be from the crank case, so I wonder if the PCV is not flowing well enough?

I'll have to drive it a few thousand more and just keep tabs on it. It could be the brakes, although I wouldn't have expected them to have that kind of an odor, especially PP brakes, but maybe that's a characteristic odor of the pads when they get hot if a caliper is seized up or the pins are seized up? I haven't really been hard on the brakes at all except on the highway a few times, so I would be quite surprised if it was coming from there, but I can't rule that out yet either.

I had this real bad after a 30 min highway drive the other day but the wierd thing is that I really only get it with my winter wheel/tire set on the car. Strong rubber burn smell on the L/drivers front. I've pulled that wheel and didn't find a rub mark anywhere.
I'm interested in one post above about the A/C compressor not turning, I'll look at that with it running next time I smell it.

Found a dead mouse in the engine compartment....got cooked to the radiator hose lol. But no that did not resolve the burning smell once the carcas was removed unfortunately, just the rotting flesh smell.

I am starting to think it could be the brembos up front. I had a bit of a grating / grinding sound from them when turning and when very light on the brake pedal, yet the pads are full (car only has 7,200 miles on it). I'm wondering if the previous owner cooked the pads or maybe that is just a characteristic of the material? There's no grooving or pitting on the rotor surface either...

They feel smooth as butter and don't appear to be malfunctioning, I don't see any signs of a sized caliper such as heavy rust on one side of the rotor....no the tires aren't rubbing, these are the same tires and wheels I had on my ecoboost which was lowered and had zero clearance issues, this is stock ride height so there's plenty of clearance, nothing is coming close to touching in the fender well or inside the wheel.

Engine is also dry as a bone just as the dealer said, as far as I can see after poking around a bit more. I couldn't find any oil around the valve covers or under the car around the headers. Only moisture was from the mouse corpse on the radiator hose ;-)