A couple of weeks ago, I had a mild miss on my 2000 4.6,
After replacing all the spark plugs I found the # 5 cylinder boot was cracked.
I replaced this and all runs well now.
NOW just the other day, I noticed a puff of light gray smoke coming from my tail pipes when I 1st start this up.
It doesn¡¦t seem to happen all the time, just when it sits all week-end long.
The motor once again is a 4.6 (year) 2000 (Make) F150, and the mileage is just over 75,000.
Is this normal on these Fords? I¡¦m pretty sure that this truck shouldn¡¦t need a valve job already¡K¡Kƒ¼
Or is there something else that could be causing this? Any help one can give would help a bunch.

Thanks in advance,
The lost One

PS I change the oil every 2.500 miles.

 

My mom's '00 E150 with the same motor started doing that around the same time, now with 98k miles it doesn't do it anymore, however it is no longer cold, and I started using mobil oil(not synthetic as it is too expensive) in it. You using 5w30?

 

I wouldn't sweat a puff at startup.

 

A friend of mine has the 5.4 and it did the same thing. Seafoam added to the crankcase stopped the problem.