E-Bodies.org Cuda Challenger Forum

Technical Shop => Engine, Transmission & Rear End => Topic started by: blown motor on April 24, 2022, 12:41:03 PM

Title: Why is the exhaust spitting?
Post by: blown motor on April 24, 2022, 12:41:03 PM
I started the Challenger (340) for the first time since last fall. I pulled out of the shop almost immediately and after about one and a half car lengths I have two trails as shown. Less than two car lengths later it was all but gone. What's happening here and what's the solution?
Title: Re: Why is the exhaust spitting?
Post by: Cudamike on April 24, 2022, 12:59:08 PM
That's condensation from starting your car. Once car warms up it goes away.
Title: Re: Why is the exhaust spitting?
Post by: dodj on April 24, 2022, 03:36:12 PM
No worries.... condensation ... You're fine.
As for a solution....... dirtier garage floor...... lol
Title: Re: Why is the exhaust spitting?
Post by: anlauto on April 24, 2022, 03:52:35 PM
You could drill weep holes at the lowest point of your mufflers...or not worry about it  :dunno:
Title: Re: Why is the exhaust spitting?
Post by: jimynick on April 24, 2022, 05:25:57 PM
As mentioned, that's condensation from the hot exhaust meeting the cold steel exhaust system. Just make sure you get the exhaust hot enough to dry out thoroughly or you'll expedite the system's corrosion. Get 'er warmed up Murray, and then put the hammer well and truly down and you should clear it out tout suite!  :cheers:
Title: Re: Why is the exhaust spitting?
Post by: blown motor on April 24, 2022, 05:29:06 PM
Quote from: dodj on April 24, 2022, 03:36:12 PM
No worries.... condensation ... You're fine.
As for a solution....... dirtier garage floor...... lol

I'll have to push it outside and then start it.  :))
Title: Re: Why is the exhaust spitting?
Post by: Filthy Filbert on April 24, 2022, 07:04:32 PM
This is why you don't start your car unless you're going to drive it.   It's condensation, a byproduct of combustion. 

Perfect combustion is Hydro carbon plus oxygen = CO2 and H2O

That water vapor that formed hits the 15' of cold steel exhaust pipe and condenses into water.   You gotta drive the car and get it hot enough to get the exhaust pipes hot enough that the water vapor stops condensing and blows out the tail pipe with the rest of the exhaust gasses. 


Also, that water vapor bypasses your ring gaps and fills your crank case with water vapor which can put water into your oil.

Again, If you're not gonna drive it, don't start it!
Title: Re: Why is the exhaust spitting?
Post by: Jay Bee on April 25, 2022, 05:33:59 AM
Here's an old picture - 2004 t0 2014, that's 10 years worth of "spit". My garage floor is covered with 4 strips of conveyor belting laid up-side-down. (PS: yes, the exhaust pipes have been changed since then.)
Title: Re: Why is the exhaust spitting?
Post by: HP_Cuda on April 25, 2022, 12:50:14 PM

Yes I would say normally that is condensation coming out your rear pipes but the first picture of this post shows what it looks like is black. My ride does this one first start up but it dries pretty quick and doesn't really leave any trace. If yours is black I hope it's not oil.

What I am saying is that normally it should not stain the ground black.
Title: Re: Why is the exhaust spitting?
Post by: Burdar on April 25, 2022, 01:39:12 PM
What exhaust is on the car?  Stockish system with mufflers at the back next to the gas tank or aftermarket system with mufflers under the rear seat?

I've said this before but when I used to work at an exhaust shop, we would use and ahl and punch a small hole in the back of the muffler at the lowest point.(right above the rolled seam at the back)  This lets the water drain out and significantly lengthens the life of a muffler.  Especially mufflers that are placed at the very back of a car.  It takes a long time for them to warm up when they are at the back.  If you have a stainless muffler, it might be easier to drill a hole then to punch one.
Title: Re: Why is the exhaust spitting?
Post by: Brads70 on April 25, 2022, 02:07:52 PM
It's crying from neglect! Get out and drive it!  :burnout:   :)
Title: Re: Why is the exhaust spitting?
Post by: blown motor on April 25, 2022, 05:05:30 PM
Quote from: HP_Cuda on April 25, 2022, 12:50:14 PM

Yes I would say normally that is condensation coming out your rear pipes but the first picture of this post shows what it looks like is black. My ride does this one first start up but it dries pretty quick and doesn't really leave any trace. If yours is black I hope it's not oil.

What I am saying is that normally it should not stain the ground black.

It's not oil. I wonder if I'm set too rich and it's puking a little soot out with the water.
Title: Re: Why is the exhaust spitting?
Post by: blown motor on April 25, 2022, 05:08:28 PM
@Burdar (https://forum.e-bodies.org/mlist/burdar_173) TTI headers and Magnaflow exhaust. The muffler always gets warmed up. I don't start it unless I'm going for a run. There's no two minute drives for this car.
Title: Re: Why is the exhaust spitting?
Post by: Cuda_mark on April 26, 2022, 05:32:00 AM
Quote from: Burdar on April 25, 2022, 01:39:12 PM
What exhaust is on the car?  Stockish system with mufflers at the back next to the gas tank or aftermarket system with mufflers under the rear seat?

I've said this before but when I used to work at an exhaust shop, we would use and ahl and punch a small hole in the back of the muffler at the lowest point.(right above the rolled seam at the back)  This lets the water drain out and significantly lengthens the life of a muffler.  Especially mufflers that are placed at the very back of a car.  It takes a long time for them to warm up when they are at the back.  If you have a stainless muffler, it might be easier to drill a hole then to punch one.

I believethe stock mufflers came with these weep holes, right? The ECS exhausts have them.
Title: Re: Why is the exhaust spitting?
Post by: HP_Cuda on April 26, 2022, 10:18:31 AM

Pull a couple of plugs and see if it's running rich.

:bigthumb:
Title: Re: Why is the exhaust spitting?
Post by: MoparCarGuy on April 26, 2022, 03:10:09 PM
FWIW the exhaust condensation mixes with the carbon soot in the exhaust system and creates carbonic acid. The acid then destroys the exhaust components. A rich-running engine makes even more carbon which deposits itself on your E-Body's rear valance and bumper. Consider a tune-up with an exhaust gas O2 sensor to check for a rich mixture.
And, as everyone agrees, always warm up and drive the car to dry out any condensate!
Title: Re: Why is the exhaust spitting?
Post by: Scooter on April 26, 2022, 04:23:17 PM
^^ Yup, looks like she is running a lil fat.