So here goes my first post!
My wife and I are new owners of a '02 Focus SE. We bought it this past December w/ roughly 96K miles on it. It was an awesome deal, but now the engine has a cold-temperature knock. The knock is clearly audible and occurs upon a cold start in below-freezing temps. Even though it's winter here in MN we have had some warmer days (40s or so) and no engine knock was heard on those mild days. Typically, the colder the air temp, the louder the knock (and general engine noise). Once the engine warms up the knock goes away.
The car has the 2.0 SPI engine in it with no known modifications and an average service record that shows no major engine repair. We have put about 2K miles on since this issue started. I wonder if this may be piston slap due to the low viscosity of cold oil, or perhaps an aging oil pump that does not perform well in the cold temps. I don't know if this is a different issue or not (or even one to begin with), but I can hear a gurgling sound in the oil dipstick when checking the oil level.
What are your thoughts?