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.
Bluish/White Smoke from tailpipe at startup.
What should in a case like this?
On Tue, 08 Jan 2008 06:30:06 +0000, jimboc rearranged some electrons to say:
I think you answered your own question.
SMOKE or STEAM?
If the latter, I suggest there is no problem at all.
Sorry, What should I DO in a case like this?
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.
Have the valve seals replaced after making sure the valve guides are ok.
Whitelightning
>Thanks!
If you would like to read the Back-Story, that resulted in my Post in this Forum, follow the two links below.
obd-codes.com/forums/Car Repair Forums - 00' Expedition Smoking:
AutomotiveForums.com > Ford > Expedition - 2000 Ford Expedition:
How would i determine that the Valve Guides are OK?
You cant with out the right measuring devices and jigs, but any decent machine shop can
Whitelightning
What do you think about Jeff's thoughts?
Jeff Compton writes: of "OBD-Codes", "Car Repair Forums": 00' Expedition Smoking
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!
On Wed, 09 Jan 2008 19:13:02 +0000, jimboc via CarKB.com rearranged some electrons to say:
No thanks. This is Usenet, not some lame web forum that simply copies Usenet traffic because they wouldn't have any postings otherwise.
Forums are not my concern, doing the right thing regarding my car is!
You seem convinced you have bad valve seals, if you are correct, you need to replace them.
If you have bad valve seals, you should notice oil consumption over time.
White smoke at start up is really steam, and is normal.
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.
thanks for your help!
You just brought is back to STEAM on start-up.
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.
this is encouraging!
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
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.
Ed
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