Weird smell after acceleration

[Mr Lahey]

GT has about 500 miles on it now. Sometimes, after a hard acceleration, there is a faint smell that lingers in the car for a few minutes.

It's almost a sweet smell. Difficult to describe it. Kinda like burning oil, kinda like burning plastic I guess.

Today, with everything warmed up, I got up to freeway speed on a cloverleaf type ramp. From 25-75, 3/4 throttle, shifting from 2nd to 3rd at about 6500 or so.

The smell, while faint, stuck around for a mile or 2. A little later, after getting off fwy, tried to replicate and got no smell.

Oil looks good, coolant level looks good. No leaks apparent. What could it be?

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[BrianJ77]

First thing I would check is to make sure to clutch line retainer is firmly clipped on the firewall stud. it's plastic and there's a recall out for it. Doubt you're car is affected since it's newer, but I would sure check that first.

 

[Mr Lahey]

First thing I would check is to make sure to clutch line retainer is firmly clipped on the firewall stud. it's plastic and there's a recall out for it. Doubt you're car is affected since it's newer, but I would sure check that first.

Looks OK. Looks like factory added a tab on firewall to attach clutch line retainer sometime after the recall. Tab right next to stud now.

 

[GrabberB]

Around the 150 - 200 mile mark I noticed a smell of burning plastic or maybe rubber. I didn't notice it until I got out of the vehicle after a short drive (no burn outs or real hard driving). The window of "miles" this occurred was relatively short. Gone by the 300 mile mark +/- which is where I am currently.

I checked clutch line retainer too and all was good. I check everywhere possible where something could be touching the exhaust and didn't see anything. This includes an underneath inspection too while up on race ramps (best I could in a tight space).

If it was something that burnt off the exhaust one would assume it would have occurred right out of the gate. Still have not idea what it was.......

 

[Mr Lahey]

Around the 150 - 200 mile mark I noticed a smell of burning plastic or maybe rubber. I didn't notice it until I got out of the vehicle after a short drive (no burn outs or real hard driving). The window of "miles" this occurred was relatively short. Gone by the 300 mile mark +/- which is where I am currently.

I checked clutch line retainer too and all was good. I check everywhere possible where something could be touching the exhaust and didn't see anything. This includes an underneath inspection too while up on race ramps (best I could in a tight space).

If it was something that burnt off the exhaust one would assume it would have occurred right out of the gate. Still have not idea what it was.......

I wonder if it's some kind of adhesive or sealant that's cooking and giving off a smell?

 

[GrabberB]

I assume it must be something along that line of reasoning. I'm not one who usually writes things off without something definitive. I was left with no choice in this case.

 

[RJV15]

When installing my H-Pipe, I noticed there are stickers on the headers, and on the mid-pipe. Thats probably some of what you are smelling, along with the residual oils from manufacturing.,

 

[Mr Lahey]

I did some digging and found some old posts on another forum about this issue. They theorized the smell was from the chopped strand fiberglass in the axle backs getting hot and starting to melt.

The smell of melting fiberglass is described as burnt cotton candy, burnt cookies, or burning glue. That seems to fit what I smell.

These guys were talking about mustangs that were from like 2010, so not sure if 2024 still uses fiberglass in the axle backs.

If so, it sounds harmless!

 

[aries4life]

If it smells like sulfur, it's your cats and it's normal.

 

[Mr Lahey]

If it smells like sulfur, it's your cats and it's normal.

Definitely got a whiff of that smell today. Don't want to completely baby it during break in so I try to do at least one 60-75% throttle pull while shifting around 6500 toward the end of a trip. Did one right before parking it and got the unmistakable smell of catalytic converters!

Haven't caught the smell from yesterday again yet, so who knows? Guess it was just a case of "burning the new off." I still like the fiberglass theory. I've got some scrap fiberglass insulation laying around. I guess I could do a little experiment and find out.

 

[GrabberB]

When installing my H-Pipe, I noticed there are stickers on the headers, and on the mid-pipe. Thats probably some of what you are smelling, along with the residual oils from manufacturing.,

Could be. I didn't notice any stickers when I inspected mine. Maybe they had burned off by the time I checked.

 

[NH_woodser]

I had the same problem, sometimes it smelled like burning oil. It was bad enough to put the car on a lift to look for a drip on the exhaust, but found nothing. Monitored a steady slight drop in the oil level on the dip stick. It went away at 1,000 miles with the first oil change. No further drop in the oil level in the next 4,000 miles. Break in oil (or cheap oil) from the factory?

 

[Ford Motor Company]

GT has about 500 miles on it now. Sometimes, after a hard acceleration, there is a faint smell that lingers in the car for a few minutes.

It's almost a sweet smell. Difficult to describe it. Kinda like burning oil, kinda like burning plastic I guess.

Today, with everything warmed up, I got up to freeway speed on a cloverleaf type ramp. From 25-75, 3/4 throttle, shifting from 2nd to 3rd at about 6500 or so.

The smell, while faint, stuck around for a mile or 2. A little later, after getting off fwy, tried to replicate and got no smell.

Oil looks good, coolant level looks good. No leaks apparent. What could it be?

Hey there. I would like to take a closer look into your acceleration odor concerns on my end. To get things started, could you please send over a message with your VIN?

 

[GWNVR DRKHRSE]

I wonder if it's some kind of adhesive or sealant that's cooking and giving off a smell?

Any update on this issue?

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