Overflow Coolant Tank Keep Draining...

I know my KW set up is different but when I had similiar issues I found expansion tank cap was not tight enough bent the fins in a little more and symptoms went away. Meanwhile I was turning my fan on manually to aviod staring at the temp guage

 

either your gauge might not be reading correctly. or the switch that turns the fan on could be faulty. ecm tester can monitor what the computer is saying the temp is when the fan kicks on. that's usually more accurate then the gauge.

and yeah, check your caps.

 

+1 on above posts. Also being a recon there is no telling if they missed a hairline crack in the head that doesn't expand until you put the motor under load. It would be easy to miss a coolant loss if some is coming out your overflow. ISX's are known for faulty EGR coolers too. They are tricky to install new gaskets and easy to mess up if you ain't the best mechanic. I would start with the cap and fan temp snesor and go from there.

 

Man this could be anything from to much coolant a bad thermostat.. To dare I say (if I am reading what you put right) a cracked liner.

Start by checking your cap...

Question.. When you take your radiator cap off is there any pressure in there? Does air escape when you take the cap off?

Is it just pushing it out the overflow tube? Not getting in oil? No visible signs under the head?

Whe was this motor recon'd .... I have dealt with trucks for along long time.. A lot longer than I have driven.. Go for the cheap fix first.. Thermostats and stuff like that but if I were a betting man I bet you have to have that thing gone through again or buy a head.

To answer your question.. Cummins is lying to you or incompetent.. Something is wrong you are right to worry... Get a second opinion.

 

I don't understand how/why the overflow side of the tank is draining to the ground. I have an '07 with the '06 ISX and my tank has 2 sides, looking from inside the cab, the right side has the cap on it, and should only be about 1/3-1/2 full. There is a very fine line on the side of the tank that faces the windshield that is the fill level when cold, I have to feel for the line. As the engine runs, if it gets hot enough it will push to the other side, on the left looking thru the windshield, but you really have to get the engine warm to put any there, and then once cool, it will draw back to the other side.
My guesses are you either have a thermostat that is not opening properly, have a crack in a head or gasket and are getting pressure into the coolant, or maybe something as simple as a bad overflow tank. But as others have said, I would start with a new plastic cap on the tank, that's the simplest and cheapest thing to try 1st.

 

Along with checking the simple things first; There is constantly small air bubbles generated in the cooling system of the engine. These bubbles need a direct route out of the engine where they can cause trouble if they gather to form a large air bubble, especially if the air hits the water pump cavity and hinders the ability of the pump. The small air bleed lines up to the tank are there to give the small bubbles a direct route out of the engine before they form the big bubble to cause problems. When the big bubble forms and becomes heated, it is super motivated to head upwards, and if the air bleed lines are blocked it will then belch its way to the tank through the larger coolant supply line and push some coolant out the cap as it comes up. Now the coolant level is low in the tank from the sudden surge in pressure of the air coming to the tank exceeding cap pressure.

 

Hello,
My name is Ben. I just find out my truck Volvo 2006 Vnl630 have the same issue with your truck. I feel so fretful about this issue. I ask any mechanics, no one can tell me the right way to fix it. I already replace all caps. But still ....Please can you tell me how you fix your truck on this issue? Thank you very much.
gybserviceinc@hotmail.com

 

Try to fill coolant system right as it recommended
Cummins Inc.
Cooling System Fill Instructions

This Installation Instruction reviews the importance of cooling system
maintenance and the impact on the engine exhaust gas recirculation (EGR)
cooler. This information has been added to Procedure 008-018 (Cooling
System) in Section 8 of the Signature™, ISX, and QSX15 Service Manual,
Bulletin 3666239.
With the introduction of engine EGR and its associated engine hardware,
performing proper coolant drain and fill procedures is extremely
important in lengthening engine life.
Be observant when filling an engine with coolant. Depending on the
coolant system, there can be special fill instructions. Watch for
information decals or tags, that contain special instructions for
filling an engine with coolant. These instructions can be located
anywhere on the cooling system (surge tank, radiator tank, radiator
mount, firewall, etc.). If no special instructions are present, search
for a manual bleed valve or pipe plug on the upper radiator pipe and
open this valve or plug during the coolant fill process. The manual
bleed valve or pipe plug will allow trapped air to escape during the
fill process. *Not* all applications have a bleed valve or pipe plug.

WARNING

Do not remove the pressure cap from a hot engine. Wait until the coolant
temperature is below 50°C [120°F] before removing the pressure cap.
Heated coolant spray or steam can cause personal injury.

WARNING

Coolant is toxic. Keep away from children and pets. If not reused,
dispose of in accordance with local environmental regulations.

The following are steps for filling an engine with a manual bleed valve
or pipe plug in the upper radiator pipe:

* Open the manual bleed valve on the upper radiator pipe, or remove
the pipe plug
* Add coolant slowly until the level is at the base of the coolant
fill neck
* Close the bleed valve on the upper radiator pipe, or install the
pipe plug. Do *not* install the coolant pressure cap at this time
* Start the engine and allow it to reach an operating temperature of
85°C [185°F], or until the thermostats opens.
* Shut the engine off and check the coolant level. Adjust the coolant
level, as necessary.

If any drained coolant remains after filling, there is an air pocket in
the system which *must* be purged. Allow the engine to reach operating
temperature and top-off the system with coolant.


NOTE: Proper fill and deareration of the system is critical to
EGR cooler life.