Coolant loss

[Gordon Maney]

My 2001 high output diesel has about 1,000 miles on it now. The coolant recovery tank had very little in it when I got the truck. I filled it to the proper mark, and have been observing it. The truck is definitely losing coolant, and I am presently trying to determine exactly at what rate, so I can tell the dealer when I take it to them. I am not smelling coolant and am not seeing it on the paving underneath it. I see no signs of coolant in the oil.



I am a little jerky about this, as my '99 Ram V10 had a really bad coolant loss problem, that was a struggle (in polite terms) to get resolved, though it was, finally resolved.



Has anyone had a coolant loss problem with the new Cummins, or do you think this is just a fluke? In addition, does this engine have any weaknesses or quirks or failure trends?

 

[EMDDIESEL]

As for coolant loss in mine, i have had it since October, have 17k miles and have added less then a quart of coolant.

 

[TomGolden]

Gordon,



Yes, I also suffered a minor coolant "loss" in my 2001. 5 ETH. I usually inspect everything under the hood each weekend when I'm going through my weekend wash/wax/inspect ritual, and it wasn't until I jad something like 11 or 12,000 miles on my truck that I started to see the level of coolant in the resevoir bottle drop. I filled it maybe 3 - 5 times for a total of about a quart or so of coolant, and it has been fine ever since. Right now I have about 19,700 miles.



I posted this same question back in February or march this year, and the most likely sounding explanation I got was that since I hadn't really been using my heater yet, there just happened to have been some air pockets in the coolant/cab heater system that were just now [back in February] working themselves out, which accounted for the apparent coolant loss.



It was suggested that even if I didn't need to, that I use the heater as much as I could for maybe a week or so, to make sure all such air pockets were worked out of the coolant system. As I haven't seen even the slightest change in fluid level in the resevoir bottle since then, I'm inclined to believe this was in fact the explanation.



Tom

 

[Loren]

Gordon,



With just 1000 miles on your truck I think it's premature to worry about coolant loss. Your truck may have been delivered with some air in the system. This air will be driven out of the system as the engine heats up. When it cools down again, coolant from the overflow/reserve tank will be sucked into the radiator.



You should continue to add coolant to the overflow/reserve tank for a bit longer and I'll bet that it will stabilize after a bit, especially if your observations show small losses that are decreasing with time. If I am correct, really loading the engine will solve this problem fast. If you pull a trailer enough to heat it up a lot, you will get most of the air out in one run.



After your previous experience with getting repairs made, I can see why you would pay close attention to this, but I haven't heard of this problem with our engines. Am I right, guys?



Naturally you will want to report it to your dealer in order to establish a record of the problem, but I think it will solve itself in a few hundred more miles.



Good luck with it. I'll be interested to hear the final solution.



Loren

 

[Alan Reagan]

Like Tom Golden, my bottle went low after about 2 or 3K. Filled it up that time and added once more a week later to get it to the full when cold line and haven't lost any more since. Figured the engine wasn't "burped" properly at the factory. I'm at 36K now and haven't really noticed any loss to evaporation either.