Learn why your car's makes a bubble or gurgling noise and how to fix
it. We are a team of ASE certified mechanics that have created this service guide
to help you save money.
How Does it Work?
A car engine can make a variety of noises. Because there are many fluids and
mechanical parts which get hot and cold there can be a gurgling noise which is
caused when problems arise.
What Goes Wrong?
In general gurgling noises are causes by internal fluids being forces through
a chamber along with a mixture of air. Some gurgling noises are normal which are
Park your car on level ground while the engine is off and in cool condition.
To start repairs an inspection is needed first so its a good idea to have a
flashlight and a set of gloves. Try to listen to the noise and see where it is
coming from so you can get a better idea what the problem may be if any.
Check for an Engine Overheating: When an
engine runs hot or overheats it can
cause a thermo lock in the cooling system
which can produce a gurgling noise inside the engine radiator. This can be due to
a stuck thermostat,
blown head gasket or a
When an engine overheats it can force coolant into the overflow container which
can create a bubbling sound. This can also be caused by a faulty radiator cap.
Never check the coolant level until the engine has cooled completely. Air can be sometimes naturally trapped inside
the system so look for a bleeder screw on one of the cooling system components such as
the thermostat housing.
Air in the Power Steering Fluid: The power steering system utilizes
hydraulic pressure which is produced by the power steering pump. If the fluid
level is low it can pull air into the system causing a gurgling noise due to the
air bubbles in the system. Check the power steering fluid level by locating the
fluid reservoir and remove the cap (twist counter clockwise). If the fluid level
is down or there is no fluid in the reservoir the system has a leak. Inspect and
replace a leaking power steering pump or hoses and rack and pinion or box assembly.
Replace worn or broken components as needed and refill system with manufacturers
recommended fluids. Allow the system to stand for a period of time to allow air
(aeration) to dissipate.
Watch the Video!
Air in the Heater Core: While the engine is running coolant is being
pushed through the heater core. When air bubbles get trapped they can make a
gurgling sound in which case the front or the rear or the front of the
be jacked up to pure the bubbles from the core. Air in the heater core can also be caused by
an excessive volume of coolant being circulated through the core. The heater core is design
to have restricted coolant flow to minimize these bubbling sounds. To repair this condition
a flow re-stricter must be installed on either the core input or outlet hose.
Gurgling When the Engine is Shut Off: Engine oil is circulated
throughout the engine when is running. When the engine is shut of this oil
which is located in the cylinder head will drain down and back into the oil pan.
This is normal and should not be thought as a problem.