Rawze.com: Rawze's ISX Technical Discussion and more

(10-25-2017 )Nilao Wrote: [ -> ]Air compressor head gasket possibly?

Replaced when I did the in frame, I was thinking compressor too, but find it odd as it fairly new and not giving me any issues.

How much pressure is built up in the cooling system at the time of the motor turning over when it starts cold in the morning? The cap is 15psi I believe.

Got a pressure checker? Start it with it installed and cold, and see if the pressure spikes over the rating on the cap. That should indicate if your cooling system is being pressurized from elsewhere.

While some fluctuations in cooling system pressure based on the water pump flow vs RPM are understandable, in general the system should slowly rise in pressure due to thermal expansion.

Does it spray like that or gush out of the overflow if you started it cold, with the cap off?

I have not tried with the cap off. I start the motor cold, cap on, she sprays, I shut her down, and immediately restart, no issue on the restart with cap on or off. The system itself does not seem to be building any pressure other than what would normally expect, a bit of water cavataion in the bottle. I put my hand over the coolant jug top for a few minutes, I felt no pressure on the palm of my bare hand at all.

That's really strange. Try the cap...worst case, you have a spare.

I'm not that familiar with a prostarwith with an isx. Any chance the hoses might have gotten crossed up if it came off? Just shooting blanks now.

Could it have been an air lock? A bubble of air the quickly expanded when you started the engine.

I'll run to town tomorrow and get a new cap, about all I can think of.

I'm trying to understand what your saying...... when you fire it up cold, it starts pissing coolant all over? Instantly or after it warms up?

If you shut it down at night and release all pressure in the coolant, is there pressure in the system in the morning?

(10-25-2017 )Waterloo Wrote: [ -> ]I have not tried with the cap off. I start the motor cold, cap on, she sprays, I shut her down, and immediately restart, no issue on the restart with cap on or off. The system itself does not seem to be building any pressure other than what would normally expect, a bit of water cavataion in the bottle. I put my hand over the coolant jug top for a few minutes, I felt no pressure on the palm of my bare hand at all.

You didn't read Cummins coolant fill instruction.
What it says -
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.