Hyundai 2008 Elantra - Manual (Page 259)

What to do in an emergency
6 6
6. If you cannot find the cause of the
overheating, wait until the engine tem-
perature has returned to normal. Then,
if coolant has been lost, carefully add
coolant to the reservoir to bring the
fluid level in the reservoir up to the
halfway mark.
7. Proceed with caution, keeping alert for
further signs of overheating. If over-
heating happens again, call an author-
ized Hyundai dealer for assistance.
CAUTION
Serious loss of coolant indicates
there is a leak in the cooling system
and this should be checked as soon
as possible by an authorized
Hyundai dealer.