When accelerating or revving the engine, I hear a gushing water type noise, very audibly through the dash, or maybe firewall. Is this the heater core, or air in the cooling system? I'm confused as my engine's cooling system is doing funny things and this seems to be one of it's oddities. I can hear it from the engine bay as well, but not as loud. My t-wagon never did this.

Check your coolant level. The sounds you're describing are common when the coolant level is low.

Yep, caused by air in the system. Craig gave good advice. Check the coolant level.

Certainly a gas of some type in the coolant. My car did this when the head gasket was blown, compression gas in the coolant. Evry morning upon start-up I would hear a rustling noise...hope your HG's are 0kay:D

It's the same problem I have with my 92 Loyale. There is air trapped in the heater core. Read the thread "wheres the heat" to see the suggestions on how to fix the problem.

 

T.J.

Originally posted by Setright

Certainly a gas of some type in the coolant. My car did this when the head gasket was blown, compression gas in the coolant. Evry morning upon start-up I would hear a rustling noise...hope your HG's are 0kay:D

 

Your car made this sound due to "air" in the system. Your air leak appeared when you had headgasket problems. Air in the system could be caused by a number of reasons. Leaky hose or waterpump. Even a bad radiator cap or radiator.

Qman, I wasnt ruling anything out

No worries, I was just clarifying for the original poster.

On some american cars, when you buy a heater core, the package comes with a flow restrictor. When the engine is revved, the water pump is going to town and coolant is being blasted through the core. The flow restrictor slows this flow down so the gushing noise won't be present.

 

It may not be air. It may be normal (or okay, cuz apparently it isn't normal).

 

I've heard this noise before in other cars that haven't got a thing wrong with them.

yeah, the guy who changed the heater core on my mom's 87 chevy celebrity wagon skipped the flow restrictor so it's super noisy now. jerk.

 

when you're filling up your coolant, start with a cool engine. take off the cap and start the car and add coolant as the level goes down. you are waiting for the thermostat to open and allow the coolant you're adding to the radiator to get into the rest of the system, including the heater core.

I think I got rid of it when I drained the rad to pull the fan thermoswitch. (I did put the water back in )