Soot Smoke at Night
 

Last week I started a thread to try and troubleshoot smoke I was seeting in WOT on my morning commute (while it was still dark). I was pretty much seeing smoke while entering the highway after about a 15 minute drive. It was more visible the colder it was. Also after a few WOT pulls it would pretty much stop. Another thing to note was that I wasn't seeing anything during the day at all (it did warm up significantly though).

I ruled out cold start steam since my car was all warmed up. It was also hard to diagnose the smoke since it was dark out and I couldn't tell what color it was. I checked my oil and coolant and didn't see any red flags.

What it basically came down to was the blackish grey smoke (Soot) that cars behind you see during the day was much more visible at night in the headlights of the car behind you. It scared the crap out of me when I first saw it but now that I know what it is, I can relax a little.

Has anyone else noticed Soot smoke being more visible in headlights at night rather than during the day? I had concurrence before but thats gone now.

Thanks!

wtf we already had this discussion

What's this? Teh Dreaded Black Soot in the Gen1 section? LOL

I know but it is gone now. I figured I would try and get this info back up here. It was good stuff!

At first it wasn't because it doesn't look black at night :)

if it is during WOT then it is most likely just that you are running rich.

AFRs are in the low 12s. To me thats pretty much at the borderline of being rich.

I've seen this to be true in my car, also. I've also seen this same phenomenon occur with stock diesel trucks. At night, it is just much more prominent because you are seeing it because of headlights behind you. My AFR's are about the same as yours. During the day it is very, very faint, but it is still there. Definitely not something I worry about.

Do you still have cats on your car?

Yup, I still have both stock cats on my car. I think my main one is on its way out though. I will find out when I have to do emissions :)

Thanks for the input.

Thanks for this thread. Ive noticed the smoke at WOT at night more recently as well. I was really concerned at first that my turbo was gonna fail and thought there was only a slight chance it could be soot. My speed is a stock 07, so Im just waiting for something to take a shit and now isn't a good time.

Thats why I started this thread. It seems like it is more obvious in the cold too.

When I originally asked the question people told me "Its condensation you dummy". It was hard to get anybody to read further in the post where I pointed out that the car was already warmed up and driven for a while. They only saw key words like morning, cold, and smoke and made an asumption from there. I'm glad to finally get a resolution to this question. It took a few people with experience driving diesel trucks to clarify this.