I have a 2008 F150 I purchased back in January. When it sits for a few days and I start it, gray/black smoke comes out of the exhaust for a few seconds. I'm not a mechanic, but this seems like it's burning oil... any thoughts??

 

being that its an 08 i'm assuming its still under warranty? oil would be blue smoke, black is gas. you may possibly have an injector leaking down slowly. is it only when it sits for a few days? how many miles? does it start up like normal? did it just start doing it? i'd take it to the dealer.

 

About 10k miles, done it on/off since I've had it but really noticing it now that I only drive it once or twice per week. I'll have to look closer, the gray smoke may be blue, but there is black smoke involved. Starts fine, runs fine.

 

my 04 has been doing this for the last year. I have had my truck to 3 different dealers for this problem. on my last visit to my local dealer they had a Ford engineer come out to take a look. Engineer suggested to have injectors cleaned then relplace plugs after 2 tanks of fuel to see if any are maybe fouled. All plugs looked good. From intial impressions I thought that maybe I have a lot of carbon buildup. I have tried the seafoam trick. Injectors have all been pulled and tested. I am also waiting for Ford engineer to get back to me. My truck has the 4.6 and also sometimes my truck sets in garage for up to 3 weeks at a time before starting. I have run mobil 1 oil in truck since 1st oil change. Just does not make sense. there are several other members on here with same issue.

 

Saw a brand new Camaro start up and have the same color smoke from the tips...