Ford Ranger 1991–1994 — technical service bulletin
Bulletin 9587 · NHTSA communication 41028 · issued Apr 1, 1995
Technical service bulletin
communication type
Engine and Engine Cooling
component
1991–1994
model years
4
vehicle entries
Official summary
A knocking/thumping noise may be audible in the passenger compartment on some vehicles due to steam formation in the cooling system. *tw
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.