330 miles, 9 gals of coolant, 36MPG

[wsmcycle]

9 gallons of coolant disappeared and none of it on the ground nor was the tow covered with it. Two days ago we traveled across Oklahoma on 40 from Sayer to Fort Smith Ar. We arrived after dark so we simply parked and drove home. Next morning, I went to move the bus. It started fine BUT before the pressure built to 100, the engine shut down. There was a warning on silverleaf; "Extremely low coolant level" I went back to the engine compartment and looked, The the five gallon buffer tank was empty. I had to add 9 gallons to get the level up to the sight glass in the tank. I looked without success to find the actual total volume of coolant the system held. The bus ran great all day and the temp never rose above 205. Usually it was 197. It was a cool day and I had the dash heat on.
I am glad that it shut down but what if we had been driving? There were no warning lights on the dash as we traveled nor when I parked it. The engine performed great all day. Plenty of power.
What's going on?

[Roy-c]

I guess the first question would be when was the last time the coolant level was checked ? That could give an indication of if all of this loss did occur on this last run or if it could have taken longer. If there are no external leaks and no oil contamination then that leaves that it went out the exhaust. That much coolant out the exhaust that quickly should have been visible. ( white smoke )
Time to put a pressure test on the system and see where it goes. If it has been a while since the level was checked it could be a very small leak somewhere. Possibly only when hot.
Also 197 to 205 seems hot to me. I would think 195 max.

[RV-LEDs]

You cold have a leak and vaporizing it. We had the same problem and haven’t found it yet. Have you changed the radiator or CAC yet if not that it is coming. You wont hurt it. The engine wont let you. If you should shut down on the road you can just turn on your pump and drag your fresh water hose back there and you can push the water in your fresh water tank back to the other end of hose and fill your water reservoir for the radiator. Been there done this. Hope this helps.

[Cat]

I'm not sure of your coach but freightliner has the coolant tank problem. The tank is famous for leaking and the engine fan blows the coolant leak around so you never really see the leak or it puddling anywhere. Next thing you know is the low coolant light and warning go off. Safe Travels

[wsmcycle]

good questions all! I had filled the system that morning because it was low in the tank sight glass. it took two gallons. So it started the day full. does anyone know how many gallons the system holds? 2005 cat c13 CC magna
I suppose that I should have put the post under "caterpillar engine" Is it too late to do that?

[Tee Jay]

Had our '06 C-13 pressure tested, found a lot of small leaks. One that surprised me is the connection to the HydroHot. That is where I would look for a leak. No where near the engine, but part of the cooling plumbing.
Terry

[tpaul]

How about a blown head gasket? Exhaust pushing into the cooling system, pushing coolant out the overflow while driving and the engine is hot. Eventually enough coolant gets pushed out that the engine starts to overheat.

[Solo_RV_Guy]

Originally Posted by wsmcycle

I suppose that I should have put the post under "caterpillar engine" Is it too late to do that?

Hi Wendel-

Not too late, with an intervention! Go up to your original post. In the left column, at the bottom, you'll see a little red triangle with an ! inside it. That's the "report to moderator" Bat Signal. You'll get a little pop up window to tell them why you're reporting it... say you realize it might be better in the CAT forum and ask if this thread can be moved.

Good luck and safe travels.

[wsmcycle]

V247-6405 exhaust pre cooler
Can someone tell me what this item does on my c13 cat? The exhaust goes through it and there is a heat exchanger inside that is supplied by the engine coolant. What is its purpose? A mechanic tells me this is the likely source of my large volume coolant loss. He said to take it loose and if the inside is wet, the heat exchanger is leaking. That is where I am headed this morning, to get it loose and examine the inside.
Thanks

[birdhunter]

That is almost the entire cooling capacity of your engine. I do not see how it is possible for you to lose that quantity in 300 miles without huge amounts of coolant pouring out from somewhere. There's no way you're vaporizing that much coolant that quickly in my opinion.
You're either burning it or it's leaking out somewhere.

Have you checked your engine oil level? If you have a blown head gasket or something and it's getting into your oil it should have raised the oil level significantly I would think. You're not blowing any white smoke?

[CountryB]

Originally Posted by wsmcycle

So it started the day full. does anyone know how many gallons the system holds? 2005 cat c13 CC magna

My 2005 Cat C13 (in my Beaver Patriot Thunder) holds 64 quarts (16 gallons) of coolant

Originally Posted by wsmcycle

V247-6405 exhaust pre cooler
Can someone tell me what this item does on my c13 cat? The exhaust goes through it and there is a heat exchanger inside that is supplied by the engine coolant. What is its purpose? A mechanic tells me this is the likely source of my large volume coolant loss. He said to take it loose and if the inside is wet, the heat exchanger is leaking. That is where I am headed this morning, to get it loose and examine the inside.
Thanks

The 2004-2006 CAT C13 ACERT engine has twin Turbochargers. The compressing of the air through two turbos causes the air to heat up a lot. CAT added the precooler to help lower the air temperature before it goes into the CAC (Charge Air Cooler).

Here's a video showing the precooler (skip to the 4:30 mark).

https://www.youtube.com/watch?v=1fsh47NQC64

[wolfe10]

No need to speculate.


Pressure test your cooling system.


As a precaution, I would also have the engine oil analyzed to make sure there was no coolant in it (coolant makes a really poor lubricant).

[wsmcycle]

I pressurized the coolant tank and saw no big leaks. Only a couple of drips from a hose coupling.
I loosed the discharge tube from the "pre-cooler". There was coolant inside. Lots of coolant. About 2 quarts.
The dip stick showed the oil level in the operating range. However when I get a new pre-cooler installed, I will change the oil.
While it makes sense that the 13psi coolant can't seep into a 40psi chamber, it happened. I attribute that to the fact that the turbo is not always putting out 40psi pressure. The "gray" question is whether air flowing across the heat exchanger was sucking out the coolant. That is a fluid dynamics question and I didn't do well in fluid dynamics. It's a fact that the pre-cooler was full of coolant, it must be leaking so I am going to replace it. 900$ and will be here tomorrow.

[wolfe10]

Glad you found it and really glad the engine did not overheat.


May be a good time to change the thermostats (Cat calls them regulators) and perhaps change coolant as well.


And, though i am not familiar with that setup, it sounds like that coolant loss ended up in the intake manifold and then went through the engine.


If that is so, definitionally change engine oil and probably do an oil analysis. Wonder if any other damage was done if 9 gallons of coolant went through the engine.