Gurgling heater core ?

[m2200b]

I changed my coolant and radiator cap along with old hoses a few weeks ago. Now I seem to get a gurgling in the dash board when I park for overnight with the nose of the car down ( and heater core up.

I don't have any leaks or coolant loss and I am suspecting maybe the new radiator cap isn't holding pressure or ? I'm out of other ideas?. It goes away after the car warms up and doesn't occur with warm starts.

 

[Dark Jedi]

take cap off and crank the engine. you prob have air pockets in your coolant system. watch till all bubbles stop then put cap back on.

 

[Ray H]

Until proved otherwise, there's no reason to suspect a brand new radiator cap. Do all coolant level checks with the car parked on a level surface. First thing, remove the radiator cap while the system is cold. If liquid is not evident right up to the sealing ring that the radiator cap's gasket mates to, you have air that needs to be purged. Simply fill up to the level of the sealing ring and replace the radiator cap. Keep checking and topping up as needed for several days until the coolant level stabilizes. It would also be advisable to keep the heater control valve pegged to the "Hot" side to aid ridding the heater core of air during the purging.

 

[Buford T. Justice]

You might also have air bleeder valves. If you do, open them once you are sure you have enough coolant in the radiator. Turn your vehicle on and wait until the coolant comes out of the valve in a steady stream. Close the valve. Be careful as the coolant will be quite hot.

 

[Big Jim]

Air in the heater core is the usual cause of heater core gurgle. It can also cause a moaning noise from the heater core.

Getting the air out can sometimes be tricky. When all else fails, you can usually get relief by bleeding the heater core. Determine which heater hose is the return hose (from the heater to the rest of the cooling system). While your helper is holding the throttle to keep the engine running at about 2500 rpm, briefly remove the hose long enough to push the air pocket out. Reinstall the hose, secure the hose clamp, clean up the mess, check coolant level. Usually you will need to push between a pint and a quart of coolant out to get the air.

Sometimes the factory used a restrictor in the heater core inlet hose to cut heater core noises, but that was usually to eliminate heater core moan.

 

[m2200b]

Thanks I'm still adding and purging with my trucks nose up. I quess I always used ramps and had the nose up before as this is the first time gurgler.

I did find this list after I posted of causes -
trapped air, including but not limited to
1) improper coolant refill and/or flush,
2) bad radiator cap,
3) leaks in hoses and/or clamps,
4) leak in heater control valve, and
5) blown head gasket.

I did add another pint and continue.