Loosing coolant....Help!!!!

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LVFISHN

Junior Member
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Jun 9, 2021
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Location
Wetumpka, Al
Ram Year
2017
Engine
6.7
New member and new Ram owner here. Bought my first diesel 2500 a couple months ago. 2017 2500 6.7. 100K miles. I absolutely love the truck. My low coolant light came on about a month ago. I added about 1/2 gallon. Now it’s getting worse. Having to add coolant about every other day. Never seen any leaks or coolant under truck. Left it running in the driveway about 30 min, no leaks, nothing under truck. Took it to the shop 2 days ago. They did a pressure check and no leaks. It held original pressure. They left it over night with operating pressure on it. No leaks, held pressure.... Where the hell is my coolant going???? Could it be a bad coolant cap??? Need some ideas as to why it’s loosing coolant. I do know it’s not a head gasket, shop changed oil and no trace of water. Help!!!!!
 

Fuel35 67

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Military
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Hanford
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2011
Engine
6.7 Cummins
Could be the h/g or turbo. Since there no signs of leaking coolant, it’s getting burnt off.
 

Wallyb4

Retired EWC(SW/AW) 1983-2003
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You could also have air in the system. If the pervious owner did a coolant flush just before you took possession there could still be some air in the system. When you get it back make sure you turn on the heat and get it up to operation temp, do this a ew times and see if you are still having to add coolant.
 

Dennis Shellito

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Dec 17, 2018
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Location
Ft. Morgan, CO
Ram Year
2011
Engine
Cummins IBS
I hear there is a test now to see if combustion gases are present in a diesels cooling system, though, previously this test was strictly for gassers. This test will eliminate a compromised HG. If the truck passes this test, the next culprit I would look at would be the EGR cooler, as they are notorious for failure about the mileage your truck has on the clock. I have read that EGR coolers can be purchased off ebay for very reasonable money, or you could remove yours and have it pressure tested. As someone previously mentioned, the turbo could have an internal coolant leak but honestly, this is very rare and I doubt this is where your missing coolant is going. BTW, is your overflow reservoir full to the top? If it is, when the engine is warmed to operating temp are there visible bubbles coming up through the coolant in the reservoir? If the answer is yes to either of these questions your truck most likely has a failed HG. I believe many Cummins owners trade or sell their truck with a bad HG rather than spend money fixing it. I was almost to the point of trading my diesel Ram in because I had the HG replaced twice under factory warranty and it didn't fix it either time, but I opted to have the repair done on my dime at a private garage. They found the head was severely warped but had a machine shop true it and now it runs good, and I am glad I went with the repair. Keep us posted.
 
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