Mechanics can you help me?bubbles,,?

Question

92 GMC pick up, when I come to a stop, I can hear bubbles comming back up through the overflow resevour,it sound like when you blow bubbles through a straw. It is not over heating or stalling out, yes the radiator is full, not leaking,and the gauge does not indicate overheating. any suggestions?

Answer 1

obviously, you have air bubbles in the cooling system. next time the engine is warmed up, feel the upper radiator hose. if it is extremely tight, the coolant is not flowing properly and is getting air bubbles coming back through the system. since that vehicle has a belt driven cooling fan, the temperature may not rise as quick, since the fan is running all the time. and are you checking the coolant level in the radiator with the engine cold or warm? if its cold, the level would be full in the radiator, but the thermostat isnt opened, so when it does, the level will drop and now you have an air pocket that you hear working itself out.

Answer 2

You may be hearing coolant circulating through the heater core. It's probably not a big deal if the vehicle isn't overheating or losing coolant.

Answer 3

When you fill it with water, your thermostat has to be open to prevent air bubbles trapped in engine. Some cars have bleeders so you can fill it up while the thermostat is closed. They are usually located by the water neck.

Answer 4

you will get air bubbles from the water pump spinning and moving the water when the engine gets to operating temp it will push a little into the overflow when it cools it is supposed to suck it back out.don't sweat it,its normal

Answer 5

93 checy pickup did the same thing it is overfilled and going through overflow hose

Answer 6

you might have overfilled it.