So you have changed the coolant bled the system and you had no waterfall sound?? Then the waterfall sound comes back? Could be head gasket air has to be getting in there some how. Test the coolant for exhaust gas and, pressure test the coolant system.

 

Sorry Mo,

Thank you for your reply. I was not very clear with what I posted. Here is what happened, I decided to change the coolant(orange) to the Peak Global Lifetime, the orange coolant has been there since I had the head gaskets changed last year. It was doing the waterfall sound right after we changed the headgasket and after repeatedly bleeding the cooling system I managed to get all the air out and it was doing okay until today when I drained and refilled the cooling system. I was doing the same procedure that I did before but the only difference is that this time I was not as successful in removing the waterfall sound in the heater lines. It was doing fine before I drained the coolant this afternoon and then the sound came back.

 

You could try priming the the heater core, I haven't tried it on a disco, but I have had it work on other vehicles I have owned

 

Okay Mo I will try and do that today. Thank you. Will let you know what happens. But usually does the bleeding procedure that is explained here in this thread, enough to remove all the air in the cooling system?

 

Ya it should I had the waterfall sound in my dash because I had a low coolant level bled it twice and it fixed it. I haven't drained the hole system though.

 

Oh you do you mean that 2 bleed cycles would eventualy get the air out of the coling system? Is it possible to install the heater core hoses in reverse thats why we cant get the air out of that part of the system?

 

Pm sent

 

Thank you drowssap. Need all the help I can get.

 

This is an update, I finally fixed the "waterfall sound". I purchased a warm climate(genuine part) gray thermostat, lower and upper radiator hose as a set from Rovers North which helped a lot. My upper hose was not the updated one, it still has the bleeder on the rubber hose instead of the T. It was easier to bleed the system with the new hose and I learned from here that the gray thermostat will keep the engine temps lower than the original thermostat.

Thank you very much to all who replied to help and shared their opinions about this issue.

 

Is there any problem with the iron plumbing T and the coolant in regard to coolant moving through the iron? Any negative affect on the coolant?