I have a 2007 F150 supercrew 4x4 5.4L engine.I have an older truck I have been driving during hunting season so the 07 sits sometimes.After sitting for 2 days or so when I start the 07 it blows a puff of blue smoke.After the initial start it doesnt do it anymore.Anyone no what the problem might be?

 

Blue means oil burning if I recall correctly.

 

No sign of using oil.

 

Your valve guides are leaking and allowing some oil to come down into the combustion chamber when your vehicle is sitting.

 

I have noticed the same thing with my 04 and my 06, Ive always thought that this is not right.

 

symptoms of bad valve stem seals.......

 

I can't see a new engine having bad valve guides...sure it could happen, but what's the chance?

I would suspect a leaking injector...especially after several hours/days of sitting. Although it won't puff BLUE smoke like oil, raw fuel will make a healthy puff on start-up. These injectors are known to leak on rare occassions, and I would lean towards this condition.

 

I want to say it's a Ford thing. I've had alot of F-150's and they've all done this. I haven't seen it on my current truck, but I think that's because I have dual exhaust out the rear now.

as long as your not burning oil...ie: it's not going down between oil changes, I'd say you're just fine. just keep carefull track of your oil consumption.

 

I agree, both of my trucks were new and no problems being low on oil between changes.