Probably valve seals on that vintage. If you let it idle at
a stop for a couple of minutes with someone following, they
will likely see the blue smoke when you start again. That
would be a classic symptom of valve seal leakage. 1qt/1k
miles is not enough to worry about to me. I am not sure
that would even meet the criteria for a warranty repair on a
new one. Mine was 1qt/150 miles when I bought the car with
67K on the clock. Valve seals on the 4.6L engine are an
expensive repair unless you can do it yourself. You would
need the usual good assortmant of hand tol plus a special
tool to release the cam followers, an air compressor and, an
air lock to hold the valve closed while you replace the
seals. I found the tool on sale for about $70US at the
time. I did my own after the dealer who I have known for
years indicated Ford was paying 11 hours warranty labor for
the job at that time. It took me longer over the course of
a weekend since I had never done one like that before.
Not easier to pull heads and will require special tool to
realign timing chain. 125 psi will do nicely. Cams do not
come out. Tool is to allow working under cam to compress
valve springs and remove cam followers and valve locks while
air pressure holds valves. I worked on cylinder at a time.
The engine can be easily turned with a large wrench on the
fan with the plugs out. Just bring each cylinder around
until the valve is closed and use the tool to open the valve
which allows you to remove the followers. Shoot the
pressure to 'er and use the tool to compress the springs and
remove the spring keeper and upper seats. Compressing the
springs is much easier if you have a longer-than-usual 3/8"
drive ratchet or breaker bar. You can then seen the remains
of the seals which can be removed with pliers. Mine came
off in multiple pieces as they were already broken. Be sure
you get all of it. Check for a carbon ridge around the stem
which should be cleaned to allow a clean seal surface. It
is a time consuming job but, my biggest problem was getting
the lower rear cam cover bolts out. I ended up having to
buy a flex shaft extension to get at 'em.
I got my tool from a tool source on the net. You can see a
picture of it here:
This is what I paid from this same source. You may want to
search around for a better price. I didn't find one. The
price you see is about $40US off retail and is only for
orders placed on the net. I did this and received the tool
in about 4 business days. OTC is the manufacturer for Ford
on this item.
Pulling the head will not only require removing the front timing chain
cover and gaskets, but will still require a special tool to compress the
springs unless the cams are removed first. The aluminum heads on the
cast iron block also require expensive head gaskets and all of the head
bolts must be replaced as they are "torque to yield".
I did this job on my '92 Grand Marquis and couldn't locate the special
Ford valve compression tool at that time, so I removed the timing cover,
timing chains and overhead cams and modified my existing valve
compression tools to work in the overhead cam head environment. I
carefully marked the cams for timing and used a pair of vise grips to
locate and immobilize the cams when reinstalling the cam timing chains.
This must be done with great care, because the 4.6L engine is an
interference engine and expensive damage can occur if not done correctly.
The cost of the valve seals from Felpro was under $30, but the car was
down for almost two weeks. I spent about a week either looking for the
special Ford tool or making new tools and modifications on my existing
tools. Get the special tool for under $70 and do yourself a favor.
I bought the car at 112k miles and it was consuming a quart every 400
miles. Afterward, I don't add any oil between 5000 mile oil changes and
I now have over 205k miles on her.
125 psi will do nicely. Cams do not
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