ISX 15 Puking Coolant From Reservoir

It sounds like excessive combustion pressure, which could be a sign that your head gasket is going to take a dump........ very soon.

 

Misread that sentence. Uggggh.

 

That is what mine did, head failed. Your's is 2011, so I am going to guess here, but I think you may have one of the last CM-871 motors. If not, it will be a CM-2250. If it is the CM-871, odds are it is your head, gasket or liner issue, they are prone to failure around that 500,000 - 700,000 mile mark. If you have the mandate still on the truck, odds are it is the head.

One test you can do, you can drain the oil and drop the pan. Then pressure test the coolant system and see if any coolant drips down from the liners. Or, you can go to NAPA and purchase a block test kit. They run around $45. It will test for exhaust gas in your coolant. That is an easy test, and I bet you will fail the test. You will know in a matter of seconds.

Or, in odd cases, it could be your air compressor releasing air into the crankcase. Drain the tanks of air, leave the tank valves open and start the truck. If you get pressure in your coolant system, it is NOT the compressor, but more than likely the head.

One thing on these heads, DO NOT replace with a reman. ONLY install a NEW OEM head. And you need to visually check the serial number, if it has RX stamped at the front of the number, it is a reman and should be avoided. Also, make sure who ever does the work, that they actually install a new head. You would be amazed at how many shops are charging for new heads and simply cleaning up and reinstalling YOUR old head, or some reman. You need to be there to visually inspect that you are getting what you are paying for. The reman head issue is very real, they tend to fail in short order. Spend the extra dollars and get a new OEM.

Also, the head bolts, do not reuse! They are one time use only when installing a new head. It is best to install them, torque, let the unit sit overnight, and then re-torque. There have been issues of bolts coming lose if not done this way. This is a Cummins issue.

 

I'm still leaning toward insufficient fluid, air or bad or wrong cap. My truck stock runs a 7 pound cap obviously 2 different motors we have. Get another cap and make sure you get the right pound cap using your vin number at the dealer. On a cold engine, start the truck up and let it run and make sure your heater core is flowing to. Observe anything you can with cap off. make sure all the bubbles are out. Start with theses simpler things first, if no success, time to start digging deeper

 

Your truck didn't have any boil over or anything coming out while truck was running at idle at operating temp?

 

It blew apart my radiator sitting idling at GM Lansing waiting to back into a dock, this was in the winter. It was blowing apart coolant hoses after replacing the radiator. And just before I took it in for the in frame, coolant was shooting out of the bottle, and I mean shooting out of the coolant bottle, well over 15 feet in the air. If it is the head, you don't have much time from what you describe.

 

The truck doesn't boil at all while idling, even under hard pull the temp doesn't hit over 200 degrees, one thing I can say is when the truck is off and the temp reaches that 210-230 degree mark, as soon as I start the engine within seconds it goes down to around 170-180 degrees, that's why we thought the thermostat was sticking but a new one from Cummins didn't make a difference

 

Do you know which motor you are running? Is it the CM-871 or the CM-2250? And what is the mileage on the unit?

 

I had no coolant in my oil when my head went.

 

Engine serial number# 79451541, quickserve shows it's an ISX15 CM2250, I just hit 748k, it's been doing this since around 731k, I have been in the shop 6 times and no one says there's an issue but the temps were never that high before and I don't know what's changed.