radiator
radiator cap
radiator filler neck
radiator hoses
radiator pressure cap
range
reach (v)
reading
ream (v)
reamer
rear
rear main seal
reassemble
rebuilt
recession (e.g. depressed)
recession (e.g. valve seat recession)
recharged
regulator
reinstall
relaxed
released
relief
relief valve
remover
repair
replace
reservoir
resistance
restricted
restriction
resurfaced (e.g. by machining)
retainer
retarded
retarded camshaft timing
retarded ignition timing
reverse
rich
ridge
ring expander
ring groove
ring travel
rings
rocker arm
rotated
rough idle
RTV
runout
ruptured
