RE This post:
https://www.dieseltruckresource.com/...74&postcount=7

Does a noisy "waterfall" sound in the cab upon startup indicated a heater core going bad? Thats what it sounds like based on that post from this thread:
https://www.dieseltruckresource.com/...ad.php?t=80747

Any input?

 

Not necessarily the heater , but it can indicate an air leak someplace in the cooling system though.
I've had 2 occurrences
A bad heater hose
A bad head gasket

 

Bad rad cap will cause this too happen too.

 

My '99 has made that sound at higher RPM since I remove the rubber sincro vortex heater amplifier from the nipple. Some where around 2250 it would burp in and out and become solid aournd 2400. Since I regeared it I don't spend enough time there for it to be an issue, so I am not worried.

Randy

 

the waterfall effect is just a sign that the coolant level is down...as the heater core is just about the highest spot in the system, or at least the lines are, air accumulates here when the coolant settles. When the truck is started, the air blasts through the core before ending up in the radiator and causes the noise. So just hearing it doesn't tell you the problem, but it does let you klnow there is a loss somewhere of many possibles.

 

I second what (got...DIESEL?) said.

 

My Mom's 96 Dodge Ram does it every day you start it but it full of coolant...

There is a TSB for this problem if it bothers you bad enough...

http://dodgeram.info/tsb/1999/09-04-99.htm

 

It very well might be a little low.. The bottom of my coolant resovoir somehow came in contact with the belt, which rubbed a hole in it, so there is NOTHING in the resovoir.

I'll have to see if I can get a new one.

 

My 96 does that every morning after I run the block heater. Goes away in about 2 minutes. I assume that when the block heater runs its boiling some of the coolant and trapping air. The noise is the air making its way thru the heater core on its way to the radiator. Other than that I never hear it.

 

Mine too- has done it since I got it (2nd owner and it was less than 3 years old when I got it) Always does it when I plug her in, usually does it on startup anyway- levels are fine and doesn't use a drip of coolant.