Coolant spraying... What is going on?

[Waterloo]

Ok, did the overhead, installed new CAC, put everything back together, went to start and I have coolant spraying everywhere! Coming out of the coolant bottle, and somewhere else. I shut it down, thinking WTF! Now what!

When I took the coolant bottle off to replace the CAC, I drained about three gallons of coolant out of the system to drain the bottle. I filled it up after getting everything back together and burped the motor.

I looked all over the motor, pressure tested the cooling system, nada.

Restarted the motor, purring like a kitten, the coolant is keeping its level in the bottle. Sits overnight, and pressure has built up in the system near as I can tell. Could it be something as simple as a bad radiator cap?

Now I start it today, and same thing! Spraying coolant everywhere, after sitting overnight. Restarted and all is fine...

Don't tell me a head gasket.

[Waterloo]

I ran up to NAPA, picked up a block test kit, no exhaust gas in the coolant. Burped the coolant system again, everything seems fine. I can't figure this out to save my life.

[snailexpress]

(10-25-2017 )Waterloo Wrote:  I ran up to NAPA, picked up a block test kit, no exhaust gas in the coolant. Burped the coolant system again, everything seems fine. I can't figure this out to save my life.

Did you fill her by Cummins manual

  Cooling System Fill Instructions.txt (Size: 3.09 KB / Downloads: 316)

[bazdan902]

Try the cap. Ynot had a similar issue I believe thinking it was time to do his motor something like 1.2 million on it. Anyways replaced cap and all has been good. If not I certainly feel sorry for ya, you can't catch a break.

[Waterloo]

(10-25-2017 )snailexpress Wrote:  

(10-25-2017 )Waterloo Wrote:  I ran up to NAPA, picked up a block test kit, no exhaust gas in the coolant. Burped the coolant system again, everything seems fine. I can't figure this out to save my life.

Did you fill her by Cummins manual

Yep, done more than a few times on her. She is running great, temp is steady, nothing weird going on with the coolant level, tested for exhaust gasses in coolant, nothing. I can't figure this out, I'll wait until morning and fire her up cold and see what happens. See if I can actually see where it is coming from. Yesterday, it was definitely spraying out of the cap, I saw that. Today, it looked like the front of the motor, but the fan was running, coolant everywhere! Maybe it is just the cap. We shall see in the morning unless someone else has any ideas?

[ynot]

I didn't have coolant spraying that bad, mine was once the motor warmed up running down the road it was blowing it out the cap, an caused it too leak in a couple other places. I put a new cap on it an the problem was solved an the other leaks stopped too oddly enough.

[dhirocz]

How full is the reservoir when you start it cold? Does it spray immediately and from where exactly?

I had a similar issue, come to find out it was because when the coolant started to get hot, the cap couldn't hold the pressure, so it just started spraying out of the overflow. Then when it cooled off, the bottle was low. New cap fixed it. Keep a spare under my bunk now.

[Nilao]

Air compressor head gasket possibly?

[Waterloo]

(10-25-2017 )dhirocz Wrote:  How full is the reservoir when you start it cold? Does it spray immediately and from where exactly?

I had a similar issue, come to find out it was because when the coolant started to get hot, the cap couldn't hold the pressure, so it just started spraying out of the overflow. Then when it cooled off, the bottle was low. New cap fixed it. Keep a spare under my bunk now.

started cold, hood was up, coolant just below max on the ProStar. Turn over engine, she fires, and coolant is raining down. First time, it was obviously coming out of the through the coolant cap on the bottle. Second time, it was hard to tell exactly, but still the same spray pattern and area. Thinking cap too.