Symptoms: The classic symptom of bad valve stem seals is, if when starting the car, after it has set for a little while (say over night), clouds of smoke appear from the exhaust and then stops after a few seconds. What happens is, while the car is setting, oil leaks down the valve stem past the seal and accumulates in the cylinder chamber. When you start the car, that oil is burned off out the exhaust pipe.
THESE ARE MY Symptoms: Bluish/White Smoke from tailpipe at startup.
"bad valve stem seals" Symptom Definition: The classic symptom of bad valve stem seals is, if when starting the car, after it has set for a little while (say over night), clouds of smoke appear from the exhaust and then stops after a few seconds. What happens is, while the car is setting, oil leaks down the valve stem past the seal and accumulates in the cylinder chamber. When you start the car, that oil is burned off out the exhaust pipe.
Jeff Compton writes: of "OBD-Codes", "Car Repair Forums": 00' Expedition Smoking
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if the valve moves laterally too much within the guide, it's mostly a feel thing. Im skeptical that the seals are dried out? I'd be still looking towards a "pcv valve" issue or a "vaccum leak" from the intake gasket, spark plug tube seals etc, I mean if it's regularly maintained then it's either a common defect, and the dealer could confirm if that's the case, or it's not the seals and guides!
i just spoke with the actual technician how will keep the car overnight sometime next week and do what he can to diagnose my problem. During our conversation he these cars don't have Valve Stem Seal problems, that the PCV Valves never go bad and if there was a hole in the Head Gasket he would have noticed it last week when he had 20 lbs. of pressure on the cooling system for 8 hours. so i think leaving it with him overnight, with my figures crossed, is the next step to take. let you know what happens late next week.
Have you ever noticed steam/smoke coming from the tail pipe of cars pulling out of a neighborhood in the morning as you drive past on the artery street/road? This is normal, and by your first post, I think this is what is coming from your Expedition.
Your Expedition has either the 4.6L or the 5.4L motor, and according to the data I have are the same motor with different stroke. (the diameter of the bore is the same, so the difference in displacement has to come from stroke.) I am new to this power plant, and I've not heard that there is any problem associated with valve seals. Your mechanic appears to hold the same knowledge.
The 5.4L has a different block with more deck height and a longer stroke. Heads are interchangeable with the 4.6L. Basic engine layout is the same. Unfortunately I have heard more than one complaint of blue smoke at start-up. If you want the opinion of a lot of Expedition owners, I'd suggest that you join the Expedition Owner's Mailing List (see
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). I no longer own an Expedition, but in the past I have owned two, a 1997 (149,000 miles) and a 2003 (100,000 miles). I never had any problems with oil smoke, but the 1997 did consume a slight amount of oil (a quart or so per 4000 miles).
One thing to consider - In the old days, blue, or blue-gray smoke at start-up, that went away in minute or two, was always considered an indicator of leaky valve stem seals. But today, because of catalytic converters, almost anything that will cause slight oil smoking will exhibit the same characteristics (i.e., it stops shortly after the engine is started). Once the catalytic converter is warmed up, it will "eat" any slight oil smoke. So it is possible that the cause is completely unrelated to the valve seals and that the slight blue smoke goes away after the engine runs briefly because the catalytic converter has started working.
I had a friend who had a 4.6L Expedition that had the slight amount of blue smoke at startup and the dealer never could fix it. The did everything short of replacing the engine - which they probably should have done. My friend is driving a GMC SUV now.
I'd suggest that the OP monitor his oil usage carefully. I also think the comment that PCV valves never go bad is bogus. If they never go bad, why does Ford replace them for free at 60,000 miles (read your warranty). My 1997 was particularly bad about coating the throttle bore with oil gunky residue. That stuff was not coming into the engine through the air filter - it was coming in via the PCV system. It is the same stuff that gums up IAC valves. I wonder if you disconnected the PCV feed to the intake manifold what would happen to the smoke.
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