2011 Hyundai Sonata Hybrid radiator cap

Your vehicle at a glance
4 2
ENGINE COMPARTMENT
OYFH071001
❈ The actual engine room in the vehicle may differ from the illustration.1. Sub relay box ....................................7-53
2. Engine coolant reservoir ...................7-24
3. Windshield washer fluid reservoir .....7-28
4. Radiator cap .....................................7-26
5. Engine oil dipstick .............................7-22
6. Engine oil filler cap ...........................7-22
7. Brake fluid reservoir ..........................7-27
8. Air cleaner.........................................7-29
9. Fuse box ...........................................7-50
10. Inverter coolant ...............................7-24
* : if equipped

Features of your vehicle
42 4
Speedometer
The speedometer indicates the speed of
the vehicle.
The speedometer is calibrated in miles
per hour and/or kilometers per hour.
Engine temperature gauge
This gauge shows the temperature of the
engine coolant when the engine start/stop
button is ON.
Do not continue driving with an overheat-
ed engine. If your vehicle overheats, refer
to “If the engine overheats” in section 6.
WARNING
Never remove the radiator cap
when the engine is hot. The engine
coolant is under pressure and
could cause severe burns. Wait
until the engine is cool before
adding coolant to the reservoir.
OYFH041047NOYFH041043N
CAUTION
If the gauge moves beyond the nor-
mal range area toward the “H” posi-
tion, it indicates overheating that
may damage the engine.

67
What to do in an emergency
IF THE ENGINE OVERHEATS
If your temperature gauge indicates over-
heating, you experience a loss of power,
or hear loud pinging or knocking, the
engine is probably too hot. If this hap-
pens, you should:
1. Pull off the road and stop as soon as it
is safe to do so.
2. Place the shift lever in P (automatic
transaxle) and set the parking brake. If
the air conditioning is on, turn it off.
3. If engine coolant is running out under
the car or steam is coming out from
the hood, stop the engine. Do not open
the hood until the coolant has stopped
running or the steaming has stopped.
If there is no visible loss of engine
coolant and no steam, leave the
engine running and check to be sure
the engine cooling fan is operating. If
the fan is not running, turn the engine
off.4. Check to see if the water pump drive
belt is missing. If it is not missing,
check to see that it is tight. If the drive
belt seems to be satisfactory, check for
coolant leaking from the radiator,
hoses or under the car. (If the air con-
ditioning had been in use, it is normal
for cold water to be draining from it
when you stop.)
5. If the water pump drive belt is broken
or engine coolant is leaking out, stop
the engine immediately and call the
nearest authorized HYUNDAI dealer
for assistance.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.
WARNING
While the engine is running, keep
hair, hands and clothing away from
moving parts such as the fan and
drive belts to prevent injury.
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.
WARNING
Do not remove the radiator cap
when the engine is hot. This may
result in coolant being blown out of
the opening and cause serious
burns.

Maintenance
2 7
ENGINE COMPARTMENT
OYFH071001
❈The actual engine room in the vehicle may differ from the illustration.1. Sub relay box
2. Engine coolant reservoir
3. Windshield washer fluid reservoir
4. Radiator cap
5. Engine oil dipstick
6. Engine oil filler cap
7. Brake fluid reservoir
8. Air cleaner
9. Fuse box
10. Inverter coolant
* : if equipped

Maintenance
20 7
Air cleaner filter
A Genuine HYUNDAI air cleaner filter is
recommended when the filter is
replaced.
Spark plugs
Make sure to install new spark plugs of
the correct heat range.
Valve clearance
Inspect excessive valve noise and/or
engine vibration and adjust if necessary.
An authorized HYUNDAI dealer should
perform the operation.
Cooling system
Check cooling system components, such
as radiator, coolant reservoir, hoses and
connections for leakage and damage.
Replace any damaged parts.
Coolant
The coolant should be changed at the
intervals specified in the maintenance
schedule.
Automatic transaxle fluid
Automatic transaxle fluid should not be
checked under normal usage conditions.
But in severe conditions, the fluid should
be changed at an authorized HYUNDAI
dealer in accordance to the scheduled
maintenance at the beginning of this
chapter.
✽ ✽
NOTICE
Automatic transaxle fluid color is basi-
cally red.
As the vehicle is driven, the automatic
transaxle fluid will begin to look darker.
It is normal condition and you should
not judge the need to replace the fluid
based upon the changed color.
Brake hoses and lines
Visually check for proper installation,
chafing, cracks, deterioration and any
leakage. Replace any deteriorated or
damaged parts immediately.
Brake fluid
Check brake fluid level in the brake fluid
reservoir. The level should be between
“MIN” and “MAX” marks on the side of
the reservoir. Use only hydraulic brake
fluid conforming to DOT 3 or DOT 4
specification.
CAUTION
The use of a non-specified fluid
could result in transaxle malfunc-
tion and failure.
Use only specified automatic
transaxle fluid. (Refer to
“Recommended lubricants and
capacities” in section 8.)

Maintenance
22 7
ENGINE OIL
Checking the engine oil level
1. Be sure the vehicle is on level ground.
2. Start the engine and allow it to reach
normal operating temperature.
3. Turn the engine off and wait for a few
minutes (about 5 minutes) for the oil to
return to the oil pan.
4. Pull the dipstick out, wipe it clean, and
re-insert it fully.5. Pull the dipstick out again and check
the level. The level should be between
F and L.
If it is near or at L, add enough oil to bring
the level to F.Do not overfill.
Use a funnel to help prevent oil from
being spilled on engine components.
Use only the specified engine oil. (Refer
to “Recommended lubricants and capaci-
ties” in section 8.)
WARNING - Radiator hose
Be very careful not to touch the
radiator hose when checking or
adding the engine oil as it may be
hot enough to burn you.
CAUTION
Do not overfill with engine oil.
Engine damage may result.
OYFH071003NOYFH071004N

Maintenance
24 7
WARNING- Removing
radiator cap
Never attempt to remove the radi-
ator cap while the engine is oper-
ating or hot. Doing so might lead
to cooling system and engine
damage and could result in seri-
ous personal injury from escap-
ing hot coolant or steam.
The engine coolant level is influ-
enced by hybrid system tempera-
ture. Before filling the engine
coolant, turn the hybrid vehicle off,
fill the engine coolant carefully.
(Continued)
COOLANT
Inverter coolant
The high-pressure cooling system has a
reservoir filled with year-round antifreeze
coolant. The reservoir is filled at the fac-
tory.
Check the antifreeze protection and
coolant level everyday.
If it is near or at MIN, add enough coolant
between MIN and MAX and check the
cooling system for air bleed at an author-
ized HYUNDAI dealer.
Engine coolant
The high-pressure cooling system has a
reservoir filled with year-round antifreeze
coolant. The reservoir is filled at the fac-
tory.
Check the antifreeze protection and
coolant level per every day, at the begin-
ning of the winter season, and before
traveling to a colder climate.
Checking the coolant level
OYFH071070N
CAUTION
Do not confuse the cap of engine
coolant and inverter coolant. If not,
the coolant circulation problem of
engine or Hybrid system may occur
because the cap pressure is different.
CAUTION
When adding coolant, be careful
not to overfill.

725
Maintenance
Check the condition and connections of
all cooling system hoses and heater
hoses. Replace any swollen or deterio-
rated hoses.
The coolant level should be filled
between F and L marks on the side of the
coolant reservoir when the engine is
cool.
If the coolant level is low, add enough
distilled (deionized) water to provide pro-
tection against freezing and corrosion.
Bring the level to F, but do not overfill. If
frequent additions are required, see an
authorized HYUNDAI dealer for a cooling
system inspection.
Recommended engine and inverter
coolant
When adding coolant, use only deion-
ized water or soft water for your vehicle
and never mix hard water in the
coolant filled at the factory. An improp-
er coolant mixture can result in serious
malfunction or engine damage.
The engine in your vehicle has aluminum
engine parts and must be protected by
an ethylene-glycol-based coolant to pre-
vent corrosion and freezing.
DO NOT USE alcohol or methanol
coolant or mix them with the specified
coolant.
Do not use a solution that contains
more than 60% antifreeze or less than
35% antifreeze, which would reduce
the effectiveness of the solution.
OYFH071005N
(Continued)
Turn the engine off and wait until
it cools down. Use extreme care
when removing the radiator cap.
Wrap a thick towel around it, and
turn it counterclockwise slowly to
the first stop. Step back while the
pressure is released from the
cooling system. When you are
sure all the pressure has been
released, press down on the cap,
using a thick towel, and continue
turning counterclockwise to
remove it.
Even if the engine is not operat-
ing, do not remove the radiator
cap or the drain plug while the
engine and radiator are hot. Hot
coolant and steam may still blow
out under pressure, causing seri-
ous injury.