I have a 2006 F-150 with a 5.4 with 85,000 miles and sometimes at startup it puts out a blue smoke. What could be causing this at that less of miles. I have a 97 f-150 with 350,000 miles and it don't do it. What could be done to mimimize this or stop it

 

A lot of time bluesmoke means your burning off oil.

 

Why would it be burning off oil

 

That generally means worn valve stem seals. When engine is shut off, oil will run down the valves, get past the seals, and go into the combustion chamber.

Seems pretty low mileage for that though.

 

mine has done that a couple times, but only does it for a second. my truck uses no oil between oil changes so i dont concern myself with it much. on a side note, my dad repaired an 08 mustang GT at his shop and after it had sat a few days it puff out a little white smoke at startup. i just assumed it was a ford mod V8 thing.

 

I believe that a little blue smoke at startup may be OK and here is why:

5W-20 oil is very thin and it gets up around the piston rings easier than a heavier oil. Now synthetic 5W-20 is even thinner and that is one of the reasons why they say synthetic is better to run in the engine, because it lubercates your piston rings more and also reduces friction between the piston and cylinder wall. But that really thin oil can get past your rings and into the combustion chamber, where it will burn. This would happen more when the engine is cold; once it is hot the metal in the piston should expand enough to cut that leak off. Do you make a lot of short trips with your truck?
Now during normal operation I have never seen any blue smoke from my 5.4 and I run synthetic. It is a very, very small amount that can get around the rings, and like I said, usually only when the engine is cold. The oil level difference would not be noticable on the dipstick in between oil changes.

Now as far as getting a very noticable blue smoke at startup, perhaps JP2085 hit it on the nose. Maybe your valve stem seals are leaking. Or maybe one of your piston rings have become compromised. Over the course of a month or two do you see a noticable change in your oil level?

 

I don't see oil consumption loss, only a couple of times when the engine is cold do I see this smoke

 

valve seals

 

I'm having the same issue with a '06 SCREW, 5.4, 2wd, 87k
Seems more pronounced after parking the truck on the side of the street, not level, tilted towards the pass side.
Doesn't do it all the time, and only on startup.
No oil consumption between changes, 5k intervals, using 5w-20 Motorcraft synthetic blend.

While its still under the ESP coverage, might as well take it in, maybe they'll have to pull the plugs to do a leakdown, save me the trouble, NOT!

Ken

 

Well symptoms sound like worn valve guides. As others have stated it sounds very premature at 88K. One other possibility but not common is the accumulation oil in the intake (likely the case for the poster that notices the smoke when he parks car on angled road).