jay c smith

I have a 2008 base convertible, automatic. It is housed in a storage unit complex. I could not drive it for a few weeks. I would start
it every day and let it run for about 15 minutes. I would rev it up a little, not much. When I did finally took it out, there was a
patch of black soot under the car. It was , I would say , in the center and around the gearshift area.
This is the first time I would it and let it run for a long time in the unit. the floor is cement. Thank you for your help.

Vette_DD

What's your question? Do you want to know what caused the soot, or do you want to know how to prevent it in the future, or do you want to know how to get rid of the soot?

sonnysucks

Thinking he wants to know where and why... o2 sensor leaking exhaust? could you have a leaky exhaust or some sort of rust (i see FL, probably not?)

Landru

A sensor leaking enough to leave soot on floor would likely trigger a CEL.

Landru

Jay, check for any codes.

rc51racer

saplumr

Somewhat leaky exhaust? It happens.

449er

I would say you have an exhaust leak in that area

jay c smith

thanks

dr_gallup

You are doing more harm than good idling that much. No need to start it every day. If you keep the battery on a maintainer no need to start it at all. Without a maintainer once every 2 weeks should be enough, let it run a little longer and get it fully warmed up and the battery charged.

BigBlok502

I'll take a wild guess that it is condensation from the exhaust dripping from one of the exhaust pipe joints, the moisture evaporates leaving a patch of black soot.

K-Spaz

condensation is my guess, leaking from one of the joints in the pipes.

owc6

Or how starting it up and running it like this the worst way to approach storing it for the winter?

maverickmk

This because you don't run it enough to ever get all the condensation out of the exhaust and oil. Then by running for such a small amount you are making the amount of condensation increase, and . . .

This. It would be better to just leave it sit.