[F22Cam]

Hello all,
this is my first post on here but I’ve been a long time viewer. I have a stock 2015 M235 that got a muffler delete done on it a couple months ago. I decieded to take a look under the car and noticed a small amount of water dripping from one of the welds in the pipes done by the shop. I read that a little bit of leakage is normal and that pipes expand when hot so it should close up once up to temp (I had just started the car prior to looking). Sometimes I smell gas under heavy acceleration too, is this a exhaust leak or something I should be worried about ?

[celsdogg]

I'd have that done again. It's probably going to get worse.

[flybywire]

Exhaust leaks are *always* something to worry about. I've experienced CO poisoning and it is not to be messed with. CO is odorless and the symptoms creep up slowly - there may or not be a headache, eventually disorientation and worse. Slow to recover from.

I wouldn't drive it with a suspected leak unless you have a CO monitor in the car. In aircraft we use chemical ones that change color on exposure, or electronic ones. The electronic kind can plug into the 12V socket.

[F22Cam]

Originally Posted by flybywire

Exhaust leaks are *always* something to worry about. I've experienced CO poisoning and it is not to be messed with. CO is odorless and the symptoms creep up slowly - there may or not be a headache, eventually disorientation and worse. Slow to recover from.

I wouldn't drive it with a suspected leak unless you have a CO monitor in the car. In aircraft we use chemical ones that change color on exposure, or electronic ones. The electronic kind can plug into the 12V socket.

Originally Posted by celsdogg

I'd have that done again. It's probably going to get worse.

Thank you guys for the fast replies. Just called the shop who did it and they said they’ll re weld it tomorrow or the next day. I’ll keep updated. I wish I had another car to drive around but it’ll have to last another day or 2. I guess I’ll just roll around with the windows down

[celsdogg]

In the mean time, how does the delete sound?

[F22Cam]

Originally Posted by celsdogg

In the mean time, how does the delete sound?

https://youtube.com/shorts/yXzQh71gZ...ziz0jgRIirxa2w

Sounds good, maybe 30-40% louder than stock. Still a little tame for my taste so I plan on going Catless after I get my inspection

[celsdogg]

👍🏽

[XutvJet]

Originally Posted by flybywire

Exhaust leaks are *always* something to worry about. I've experienced CO poisoning and it is not to be messed with. CO is odorless and the symptoms creep up slowly - there may or not be a headache, eventually disorientation and worse. Slow to recover from.

I wouldn't drive it with a suspected leak unless you have a CO monitor in the car. In aircraft we use chemical ones that change color on exposure, or electronic ones. The electronic kind can plug into the 12V socket.

Unless you're in an enclosed space for long period of time (i.e. like a closed garage), the CO from an exhaust leak isn't going to do anything to you and even then, the CO emitting from the tail pipes is what will kill you. Think about it, in almost all instances of driving, the car is in the atmosphere with tons of air movement around the car, even when sitting still. CO build up in the car wouldn't even register. Heck, you're more exposed to CO from the cars around you when you're sitting at a light with the windows down.

[atek]

definitely have the shop re-weld it. Looks like a terrible weld job from that photo alone.

[F22Cam]

UPDATE:

I got the welds fixed at the shop this morning for no cost, so I was happy about that.

Then I proceeded to blow my charge pipe on the way home. Just great! Literally planned on getting it done next month.

Car will be down until the VRSF one comes in and I can install it.

[flybywire]

CO risk depends on where the leak is, where the cabin air intakes are, etc.

https://www.abe.iastate.edu/extensio...icles-aen-208/

Why are defective exhaust systems so dangerous? Internal combustion gasoline engines produce extremely high carbon monoxide concentrations. Even a properly tuned gasoline engine, will produce more than 30,000 parts per million (ppm) of CO in the exhaust stream before the catalytic converter. An exhaust leak can allow escape of CO before it is converted to non-toxic CO2 in the catalytic converter. The CO leaking from the exhaust system can enter the vehicle through holes in the body or open windows or doors. Exhaust systems must be gas tight from the engine to the end of the tailpipe.

How does the catalytic converter reduce the risks of CO poisoning? The typical catalytic converter found on most newer cars and trucks combines oxygen with carbon monoxide to form non-poisonous carbon dioxide (CO2) reducing the high concentrations in the exhaust manifold (typically 30,000 ppm or more) to low concentrations (typically below 1,000 ppm after the catalytic converter). Tailpipe concentrations of carbon monoxide in gasoline engines without catalytic converters are typically from 30,000 to over 100,000 ppm, depending on the condition of the engine.

How can CO poisoning occur if the engine has a catalytic converter? Exhaust gas that leaks out before the catalytic converter has high CO concentrations. Out-of-tune or misfiring engines produce elevated concentrations of carbon monoxide and unburned fuel that can destroy the catalytic converter. During cold starts the catalytic converter is ineffective. And if there is insufficient oxygen (caused by operation in a closed building or with a defective oxygen system), there will not be enough oxygen for oxidizing the CO to CO2.

[John in VA]

To the OP - you should go back & edit/correct the spelling of exhaust in the subject line so others with this issue will be able to find this thread.

[XutvJet]

Originally Posted by flybywire

CO risk depends on where the leak is, where the cabin air intakes are, etc.

https://www.abe.iastate.edu/extensio...icles-aen-208/

Why are defective exhaust systems so dangerous? Internal combustion gasoline engines produce extremely high carbon monoxide concentrations. Even a properly tuned gasoline engine, will produce more than 30,000 parts per million (ppm) of CO in the exhaust stream before the catalytic converter. An exhaust leak can allow escape of CO before it is converted to non-toxic CO2 in the catalytic converter. The CO leaking from the exhaust system can enter the vehicle through holes in the body or open windows or doors. Exhaust systems must be gas tight from the engine to the end of the tailpipe.

How does the catalytic converter reduce the risks of CO poisoning? The typical catalytic converter found on most newer cars and trucks combines oxygen with carbon monoxide to form non-poisonous carbon dioxide (CO2) reducing the high concentrations in the exhaust manifold (typically 30,000 ppm or more) to low concentrations (typically below 1,000 ppm after the catalytic converter). Tailpipe concentrations of carbon monoxide in gasoline engines without catalytic converters are typically from 30,000 to over 100,000 ppm, depending on the condition of the engine.

How can CO poisoning occur if the engine has a catalytic converter? Exhaust gas that leaks out before the catalytic converter has high CO concentrations. Out-of-tune or misfiring engines produce elevated concentrations of carbon monoxide and unburned fuel that can destroy the catalytic converter. During cold starts the catalytic converter is ineffective. And if there is insufficient oxygen (caused by operation in a closed building or with a defective oxygen system), there will not be enough oxygen for oxidizing the CO to CO2.

The cabin intake on the 2 series and most every other car on the market pulls air in from the base of the windshield. There are flapper vent doors in the rear of the car (typically under the rear bumper cover) that reduce positive pressure inside the cabin, but they don't leak air in, only out.

Unless you're running a car inside an enclosed space, you're not going to suffocate yourself from CO poisoning. FYI, exhaust systems are not air tight either. They leak slightly at the seams/connection points after the cat.