"Moo" Sound Coming From Thermostat?
 

Hey guys I just replaced my radiator a few days ago and still in the process of burping out the system. I've yet to completely fill up the system as each time I've driven since I came home to find that it needs more coolant. I've also notice that I'm getting a "Moo" sound just as I step on the throttle for a slight second.

I'm 100% sure its not the air pump as I've already done the mod to eliminate that sound, i.e the door stop with a few holes in it technique.

My question is....when the thermostat or filler neck is low or empty does it have a tendency to make a "moo" sound similar to the air pump?

Anyone?

Only the ACV discharge system which goes through the top of the air box make the moo-fart sound.

Either you did not fix it, or you have combustion gases leaking into your cooling system and when the gas blows through the rad cap it's mooing.

Have you run over any cows lately?

I've never had this problem before. So your saying the thermostat makes no noise or "moo" sound whatsoever when it opens up, especially when its very low on coolant?

Ok guys I found out the source of the problem and yes it wasn't the thermostat.

I went for a test drive around the block and I suddenly lost all power, i.e at WOT I was getting 0 psi. Got home checked the hoses and there was a huge boost leak coming from the stock CRV. So I conclude by saying that if with a boost leak of this size it also makes a "moo" sound.