Originally posted by tiv:
I've changed the oil the day before yesterday (from 5k mi
old Castrol Syntec to new oil of the same kind).
The car is a '97 Zetec with 155k, I've been using synth
or blend since 110k, 5W30 always, changing between 3k-5k
depending on traffic pattern.

I'm not consistent on the kind of oil,I pick it depending
on my mood/wallet at the moment (synth or blend). Been using
Castrol frequently (not exclusively) because it's cheap.
I use Motorcraft filters all the time, FL-200 or FL-300
(Walmart gives one, dealer gives another, I guess they're
the same. Both fits.)

At this oil change what came out looked as thick and
black as I expected from an 5k / 3month old oil, nothing
particular. After filling up with the new oil, the sound of
the engine changed very much, I'd say for the better: much
smoother idle, nicer sound.
It changed so much that even a friend who occasionaly rides
in the car noticed it.

I've never had anything like this before, and I'm quite
puzzled. The engine is still in a good shape, doesn't burn
or leak oil.

Any comments ? What could cause this ?

Thanks,
Tiv





For about $10-$15 you can have your oil checked at a lab. Most the autoparts houses know where to send it. They do a whole range of tests, you might want to try this just out of curiousity and especially since you stated you noticed a marked difference in how yourengine ran after changing oil.


Ken, 99 Silver Frost SE Zetec Atx, polished alloys, Kumho's, Pioneer hi power CD/AM/FM. Factory spoiler (added) Audi side lites, Borla stainless steel muff. Stolen, recovered in pieces. Looking for another Tour, preferably V6, 5 speed.