This probably has been talked about to death but for the people whosr trucks puffed blue smoke on start up, what has been done for you? My dealer gives me the run around, so I started experimenting myself. I use only Ford oil and filter, try stopping short distance driving and quit babying my truck. This smoke goes back to when the truck was new. Has anyone with the same problem (4.6) figured out what the problem is. When Ford techs dont know what it is, and I understand quite common among the 4.6, what does that tell us?

 

I have seen a lot of posts related to carbon buildup in the Intake Plenum. I think the only way those deposits can get there is from the EGR or PCV hoses.

My guess is that oil is being sucked into the intake and causeing the smoke.

The PCV theory could be tested by removing it and plugging the hose with something. Just be warned that explosive gases in the crankcase are sucked back into the air intake thru the PCV valve and this one-way valve prevents the gases in the crankcase from being ignited if an engine backfire occurs. I think I read in the Lightning forums where they put their own oil seperators the PCV lines to trap the oil. There is another hose that is usually right before the throttle body that goes to the drivers side of the engine to feed fresh air into the oil crankcase. I think its possible that oil could get sucked back up through this hose also.

http://66.179.14.118/forums/showthre...=oil+seperator

See "Blue smoke is from oil burning".

http://www.2carpros.com/topics/bluesmok.htm

Another possibility is that oil is dripping down the valves and getting into the cylinder when the engine is shut off.

If your truck is not burning loads of oil then its a minor design issue with the engine. Nothing to worry about mate.

 

I would bet money your valve guides are too big, or not tight enough around the valve stems. I don't think it is a serious problem, but if it is under warranty, it is worth pursuing with the dealer.

 

our 97 has teh same thing occasionally at cold start-up. Unless it's excessive, it's normal. If it's a newer truck under warranty have a technician take a look.