Just looking for other suggestions on what to check, and TIA
> New to us used coach about 16 months ago. Had just under 40K when we bought it, and due to life now a bit under 46K. 07 coach, with 06 Smog Level ISX600 CM870 (EGR but no DPF).
> May have been losing coolant since the day we bought it, but started to monitor the Reservoir Tank this year, and noticed the coolant starting to drop in the glass tube monitor. (All coolant level checking done with level coach, and cold engine before a days travel.)
> We went from Yuma to Montana, and Montana to Oregon Coast, and then Oregon to Yuma again - since the end of June.
> In Twin Falls, ID, heading to Oregon, I added another gallon of Coolant, and marked the location as a new Baseline on some blue tape I added to the side of the tank next to the glass tube reader. And because I could detect no signs of leaks anywhere else. (Hoses, Clamps, Radiator, Water Pump, Heating Hose to front OTR Heater, OTR Heater unit, School Bus Pumps (Rear bypassed by previous owner.), etc. etc.) The only place I thought I saw residue, was on the frame below the Reservoir tanks Overflow Tube/Hose. So I went ahead and located I feel a good quality Radiator Cap at a Peterbuilt/Kenworth shop in Twin Falls. 16LBS, which is the same as the one that was on it when we took delivery.
> From Twin Falls to Oregon Coast, three days of travel. The coolant level dropped two out of the three
days. And at the fill up of fuel stop on the third day, I could see coolant dripping below the Overflow Tube/Hose.
> I made an appointment for help at Coburg Cummins. And taped a water bottle to the bottom of the Overflow Tube/Hose. The day we ran over for the appointment, we drove and extra hour to get at least 100 miles on run over. The bottle was full and had overflowed on that 100 mile run.
> Cummins Tech's: Leak Tested the Cooling System and Turbo; Removed hoses and tubes to visually inspect the EGR and Compressor for Moisture (None detected.); Pulled samples of Oil and Coolant for analysis. No coolant found in oil, and no exhaust found in coolant.
> At this time the coolant was about 1/2 way or so down, and about a 3 1/2(?) gallon or so reservoir. As the coach was new to me, and those tests came back good, and with some guidance from a few others - I thought 'It has not found where the reservoir tank likes to level off yet, for this specific coach.' (I knew at PDI, they had added coolant to the tank too. When I started observing and noticing it, it was about 3/4 full, and when hot would arise about 1" with plant of room to not be 'Full' in the sight glass tube.). So, I decided to drive and monitor, and see if it would 'reach a level' and stop spitting out coolant.
> Weeks of enjoying Oregon Coast, and Club Premier Services 50A, I drove to Yuma. Another three days of travel. And another one where two out of three days of travel, coolant was lost/dropped - spitting out the Overflow Tube/Hose.
And now, the coolant was lower down in the sight glass tube then I felt it should be. About 1 1/2" of coolant visible.
> So while here at Yuma, I put the water bottle taped back onto the Overflow Tube/Hose, and ran the engine until the Thermostat opened temperature wise.
Bottle which I had taped on had had about 1/2 full of water. With engine running, I could watch a steady bubbling of and the water was turning the ES Complete light blue.
> Removed the new Radiator Cap, and it seemed to have a good seal, as the gasket had an indentation all the way around it. But to because it was cheap cost, I locked another good quality (Actually looks to be the same Radiator Cap, from RUSH trucks. Much more 'solidly' built then the one that NAPA had in stock. And almost twice as expensive too.).
> So second New Radiator Cap installed. And reran the test again, getting up Thermostat opening temperatures. (I was popular here at the RV Park, two times running the engine at higher RPM's for just under 30 mins!)
No bubbling this time, and no signs of any coloration of the freshly half filled water bottle.
> So, OK! Wow, perhaps I had a bad cap, and then replaced with a new bad cap too... Those things happen!!!
But, it's the 'two out of three days'
of coolant lossage that has me a bit confused. Some variation in condition is taking place. A bad radiator cap, would have spit out coolant under all three days of travel(?) - is my thinking.
> I have to go back and review our route from Twin Falls to Oregon those three days of travel. But I know for a fact that the route I took from Oregon to Yuma, had Day 1 and Day 3 of pretty good grades to climb, and I downshift and have the ISX running at much higher RPM's and Boost on those grades. And the same about the downgrades, those two days of coolant lossage - also had heavier Jake Brake Activity too. (The stretch from Corning to Bakersfield on I5 South, was a loafing along day as far as grades were concerned, very seldom saw 5th gear when up to travel speed on that day.)
I believe my first day of travel from Twin Falls, ID to Redmond, OR - was also a relatively easy day of travel grade wise. (And need to check my notes on this, I think that was the day we did not lose any coolant, Day 1.)
OK? So great if it was a bad radiator cap, or a radiator cap seal that was compromised under higher pressure conditions. Temperature via gauge and SilverLeaf were always below 200F, usually running 187-192F when loafing, and on grades maybe 197-8F... (The highest I ever saw, on this new to me RV, was 205F or so, and that was with me pushing the rig hard in 6th gear from Needles to Las Vegas long gradual grade, in 117-124F run. (I was testing to see how the cooling system did, and I thought it did great... As I normally would have downshifted to 5th, but the tad bit of torque with the ISX pulled the grade fine in 6th.)
When we put the coach in storage next week. We'll drive for an hour or so on I8 just to see what happens with the coolant level. Dropping, or not dropping... Due to what maybe a 'variable condition'(?) causing the lossage.
So input and advice on other things to check appreciated!! Here is what I have so far:
- EGR Cooler (For internal cracks)
- Even though the Coolant and Oil Samples analysis came back clean, Head Gasket and or Cracked Head. (But again, while two out of three only?)
- Slipped Liner (On this young of miles and hours engine.. Well not likely (I hope
Any input other things to check, appreciated
! And thanks to all that read all the way thru this post... Trying to info share on what has been done over these few months, with few days, of traveling under our belts!!
Best to all,