Sudden Loss of Coolant while parked, not idling.

If this has already been covered, I apologize.

I'm lease purchasing an 06 Columbia, with a Detroit Series 60. Inframe rebuild done approximately 100k ago. New turbo, EGR valve, EGR cooler, Fan Clutch assembly, all recently replaced, within the last 1 month. I had the guy in Effingham do a ECM reflash Feb 1st, turned up horsepower, set the injectors the same, take out lag on turbo, and whatever other settings he does.

One week after ECM reflashed, the turbo, ECM cooler, and Fan clutch assembly were replaced. That gave me a lot of difference on fuel mileage. Three weeks after those 3 items had been replaced, the EGR valve stuck open, and I was on the road, so I was sent to the local Freightliner dealer. 3 days after I checked it in, it was fixed and running strong, but not doing as well on fuel mileage. Still in the mid 5's under heavy load. Light load was doing low 6 MPG.

Fast forward a week and a half......I'm parked for the night in truck stop. Temps are about low 40's, down to high 30's for the overnight low. I don't idle when I can stand the temps, so I wasn't idling once I got parked. I get up the next morning, and do my walk around pretrip. The first thing I saw was fresh green coolant puddled around my front tires. I raise the hood hoping it wasn't me who was loosing coolant.......no such luck. My coolant recovery tank was completely empty. I saw nothing on any clamp points on my plumbing that indicated a loose clamp was the cause. I did see a drip of coolant coming from the back of the engine and dripping off the flywheel cover. I called maintenance at my lease company. They recommended replacing coolant and checking for leaks. Good idea, duh..... when that was done, I started it and let it idle to warm up to operating temps. After going in to get coffee, I came back out and did a final check under the hood. No green leaks anywhere that I could see.

I drove it to my pick up 6 miles away and got my load on. Again checked under the hood, and on the ground. No evidence of it ever having had a leak. I drove it all day yesterday, about 550 miles. Nothing. No problem with temps all day. When I stopped to take my HOS 30 minute break, later, I raised the hood, and still saw no leaking.


My question is what could have caused the sudden loss of coolant. An overflow out of the overflow tube wouldn't have blown out all the coolant, so where did it go?

Oh, it did develop something going on with turbo. Related to this, I don't know.

 

Oh the famous cold water leak! Now to see what kind of plumbing is back there is the problem. A heat hose, maybe......

Thanks for the heads up

 

Thanks to all responding to this.....I was empty......temp on dash was showing normal around 190......I did drive into the parking area and drove around for a bit looking for a spot to back into. I idled a bit while I did my logbook and then shut it down.....So whether I was trying to be correct in the way I should shut down, I shut down in the manner described by the responses. My recovery tank was operating at the "maximum when cold" line when it was at normal operating temps.

 

You win the prize......I left a large tub under the engine last night when I came in. After I posted this this morning I went out to check the tub, and found coolant in the tub. And then still didn't see where it was, until my Son saw a drip. It is the water pump. It is somewhere where the water pump gasket is. It was dripping off a bolt, down to a drain plug, and then running down under it to the crankcase pan, back to the rear of the engine.

I put some Bars Leak stop leak in the recovery tank and idled it for about 45 minutes, and of course while the coolant was at the operating temp it wasn't leaking. So with the stop leak in it tonight, I'll find out in the morning whether it is stopped. I'll still have to have the shop fix it.