98SVTC nailed it.
This is also posted on our old Main Site FAQ and mentioned as "harmless".
"FORD CONTOUR TIMING CHAIN CLATTER
Ford TSB 97-2-8 describes a clattering noise at engine start-up after the engine has sit overnight that may be heard on 1995 Ford Contour and Mercury Mystique models with a DOHC 2.5L V6. Oil leaking out of the chain tensioners causes the timing chain to momentarily rub against the tensioner ratchet when the engine is first started. The noise only lasts a couple of seconds and goes away as soon as the engine builds up oil pressure.
The cure, says Ford, is to replace the original chain tensioner components with redesigned parts. These include two timing chain tensioners F5RZ-6L266-CA, the left hand tensioner adapter F5RZ-6C275-BA, the right hand tensioner adapter F5RZ-6C275-AA, the left hand chain tensioner arm F6RZ-6L253-AA and the right hand chain tensioner arm F6RZ-6L253-BA. The two DOHC timing chains and guide assemblies should also be replaced at the same time.
TIMING CHAIN TIPS
When replacing a timing chain on any Ford engine, always replace the chain, camshaft and crankshaft sprockets. Don't reuse the old sprockets to save time or money. All three components wear as a system and should be replaced as a matched three-piece set. Some OHC kits also include chain guides and/or tensioners. These "extra" parts play a vital role in supporting the chain and keeping it tight and should also be replaced at the same time."