Alright, I've got a D1 with a recent head gasket job (1k miles since). At the same time, I also replaced the radiator (Nissens) and water pump. I'd noticed a little gurgle below the dash (air cycling through the heater core) since the head gasket was done, so I did a coolant burp this weekend (spillproof funnel type). Now, my gurgle is worse. I know it's really just a meaningless sound, especially because of how cool my truck runs (195 max), but it's driving me crazy! My knowledge on this subject has run out, does anyone know what's happening? I had the heat on full blast while I was burping it. Also I should mention that I hear it even when the heat is not on. I'm not sure if coolant still cycles through the heater core even when the heat is not on. Help!

 

Just giving this a bump. Nobody has any ideas on this?

 

Swap the heater hoses and run it for a day or so, then swap back. Works well for me.

 

x2 on that,it worked so well for me that i left it that way and haven't had the water sounds since.since there are no inline valve the heater core doesn't know the difference,but if you do disconnect upper hoses it's worth flushing [and reverse] firstmmaybe even a clr-water mix to soak then blow it out and reconnect

 

I have the gurgle too, just poor loop design regarding height.

Thanks for the suggestion above, had not thought of that. For now, as long as the main motor cooling loop is ok and I have good heat I choose to leave it be.

 

hasn't changed anything for me [regarding heater] same warm air and no affect on cooling temps either way i ran it

 

It still sounds like there is air in the system. Just a headsup, don't rev the engine at all when you are doing the bleed.
Getting all the air out is such and easy process, especially if you are using a funnel. That's the ONLY way I do a coolant bleed.

> Screw the funnel into the top of the radiator, fill it AND the funnel.
Let the expansion tank get just under half full and then LEAVE the CAP ON while you do this process.

> Start the engine, and let it run AT IDLE ONLY. It's going to take several minutes (maybe 8-10) until the thermostat opens. When it does, you're going to see some BIG bubble belch up through the funnel, and the level in the funnel is going to drop. Watch for this and DON'T let the level in the funnel drop to empty. KEEP THE FUNNEL FULL or you will just suck more air in!

> Now turn the HEAT On. More bubbles will keep coming, some fluid may spill over (that's avoidable just depends on the funnel size). At some point, the level in the funnel is going to drop ALOT. That's when the air pocket finally made it's way to the radiator.

> Leave the engine running, with the funnel filled for about 15 minutes. NEVER at any time during this process rev the engine. This will only cavitate the pockets of air, AND you'll spill the funnel over and induce more air into the system. Key thing is to keep the funnel full, this keeps air out and a slight hydrostatic head of water to slowly drain into the radiator as it displaces the escaping air.

> Let the engine cool, remove the Expansion Tank Cap and the coolant in the funnel will then empty into the expansion tank.
Adjust the coolant level in the tank and your done.