Sulfur Smell When I Floor It

Hi Folks,

I have a 2021 CX-5 Signature. Currently has 19K miles. I notice that whenever I floor the car in regular or sport mode, a sulfur smells enters the cabin. I am wondering if this is normal with these turbo skyactiv engines, or if it could be a leak in the exhaust manifold, problem with the catalytic converter, faulty fuel filter or fuel pressure sensor, etc. It ONLY happens when I floor it. Otherwise I do not smell anything. Has anyone else experienced this? Thanks for any feedback!
 

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Well WOT is only in actuality likely to be only 90-95% ECU calibrated. But that is another topic altogether. Why would you need to WOT unless racing? Never mind don't answer. haha. Your engine technically is just barley fully broken in. eeek!
The sulfur smell is likely caused from quickly super heating the CAT and the spark plugs not having a clean developed kernel due to normal daily driving and how the ECU regulates the fueling, timing and several other perimeters. Those "adaptive" you often read about based on the most current and regular driving habits which I hope is not flooring the throttle frequently.
Basically, unless you smell it all the time under all driving habits and your fuel MPG goes down, you notice a distinct decline in power then it's a normal smell. If it were a leak, you not only would hear it predominately when you did a cold start, but you would also smell exhaust all the time.

P.S. I highly recommend using the highest octane available if you are going to continue to have fun like flooring to WOT in your MAZDA. The ECU can only protect the engine so much using lower octane fuels.
 
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Any strangeness that you feel is not normally heard from your MAZDA's transmission of shifting event should be checked out at your MAZDA dealership ASAP.
I personally do not trust or believe in the lifetime no service transmission. It has already been proven that break in material from the new transmission does not all get filtered in the pans filter and settles to the bottom of the pan. If during the course of driving a windage is created in the pan those settled particles could be reintroduced into the transmission main operating area's. Whether or not it could affect wear is really not been tested anywhere. But I for one would hate to have the warranty expire and the day after the transmission fail?
I for one would at least consider having a pan fluid and filter service done. It will NOT void your warranty and will at least clean up the fluid slightly and also rid the pan and pan magnet of the collect break in material.
 
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CX5 GT
at 19k miles its waste of money to change then trans oil.
Op there isnt anything wrong based on what you describe but feel free to go the dealer for quick check
 

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at 19k miles its waste of money to change then trans oil.
Op there isnt anything wrong based on what you describe but feel free to go the dealer for quick check
This is absolutely incorrect? If you read my post then you would understand why, maybe.

There are several Oil Analisis companies that you can contact, and they will be happy to explain to you and most likely say the same thing I posted.
Here is one I have used a few times.
And I just did with my 2019 Nissan Sentra with 50k miles. I bought it used but thought only prudent to change the pan oil and filter. Took about an hour and half . I also did it on my MAZDA that was very easy took an hour. It was well worth it and did show everything I mentioned in the first response. The service was at 15k miles and again at 23k miles in which I had the oil analyzed.
Oil sample | Blackstone Laboratories

My question to you is did you have it done to your personal Mazda and that is why you are saying it was a waste of money? ;)


This is the information conclusion and note again this was a sampling at my second oil pan and filter service.
 

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sm1ke

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Canada
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'18 CX-9 Signature
I notice when I am slowing to a stop a I hear a clicking/clunking sound when the automatic transmission gears down from 2nd to 1st gear. I have read online others complaining of this but they also seem to have a lurching affect. I have no lurching, just the clicking/clunking sound. Is this normal? I just want to make sure it not a transmission problem, again since the car is still under warranty.

If possible, recreate the issue and record the results on video. Then take it to the dealer and show it to them. Or you can request that a tech ride along with you while you attempt to recreate the issue. The car is still under warranty, so I would let the dealer do what they are supposed to, and diagnose/troubleshoot the issue themselves. It is their problem to fix.
 
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'16.5 CX-5 AWD
The only vehicle I ever had that smelled of burnt sulfur was a 1990 Ranger. It ended up having a bad ECU that sent improper A/F mixtures to the engine. I'd run it by the dealer and ask.
 
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2022 CX-5 Turbo
OP,
Your CX5 might have a gasket leak.
The smell enters the cabin.

My old BMW5 had a gasket leak. I could smell gasoline under the hood and in the cabin if not in recirculation mode.

Once the gasket was replaced, A-OK.
See if you can smell it under the hood.
 
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2016.5 CX-5 GT AWD titanium/black 2016 Miata Club ST MT white
Normally when one smells this sulfur smell it's from behind a vehicle that has a malfunctioning catalytic converter. Dunno how that smell could come from your car, and you smell it in the cabin though.
 

sm1ke

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Canada
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'18 CX-9 Signature
I suspect two names, one IP address.

IP address showed no shared accounts. They probably used some other way to avoid detection. Based on their nature and what other users have said about this person after encountering them on different forums, it seems that this isn't the first time they've circumvented a ban before.
 

acidbug

ZoomZoom CX-5
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‘19 CX-5 GTR
Sulfur smell is typically from cheap gas (most notable app WOT). If you are smelling it in the cabin then there is a high possibility there is an exhaust leak in the engine bay.

As others had mentioned, you can typically hear an exhaust leak during cold start.

Take it into service and if they claim they can’t smell it go for a ride with the service tech and reproduce the issue. Make sure to fill with the same cheap gas as it will be more detectable than the smell of quality/Top Tier gas when your car has an exhaust leak.
 
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2016.5 CX-5 GT AWD titanium/black 2016 Miata Club ST MT white
Sulfur smell is typically from cheap gas (most notable app WOT). If you are smelling it in the cabin then there is a high possibility there is an exhaust leak in the engine bay.

As others had mentioned, you can typically hear an exhaust leak during cold start.

Take it into service and if they claim they can’t smell it go for a ride with the service tech and reproduce the issue. Make sure to fill with the same cheap gas as it will be more detectable than the smell of quality/Top Tier gas when your car has an exhaust leak.

I disagree with this hypothesis. Over the course of ~50 years of driving, not once have I had any of my vehicles smell like sulfur. And yes, I've used plenty of cheap gas over the years.

YMMV