Kim (skyking4ar2) Bertram
Moderator Emeritus
Long read?.
We have a 450hp ISL 9 Cummins, rear radiator, in our 2012 Thor Tuscany 42RQ. Five years on the road full time and 42,000 miles with zero issues with coolant of any kind.
Coolant is disappearing from my system and Freightliner 24/7 and Freightliner shops have been engaged and we are still struggling to isolate the issue. The story follows and I am looking for any user insight into the issue.
The issue began with a top radiator hose clamp that was loose, forcing a catastrophic coolant loss, and a resulting $1,000 wrecker ride. Farmington Freightliner replaced the clamp, refilled the radiator with Alliance 50/50 coolant, pressure tested the system for leaks and off we went.
Over the next 5,000 miles from NM to Alaska, we would periodically get a low coolant light, stop, refill the tank with the same Alliance coolant, 50/50, and proceed. Over the course of the trip and back, this issue continued to occur, especially on long grades, and ultimately with a stop engine light. During these times, and with a five year history of driving this rig, I never saw abnormal temps, and typically any time temps rose to 212 digital, the fan would kick in, and the temps would immediately respond lower.
Just in case, I replaced the radiator cap with a 16# Freightliner cap after recommendation from FCCC Service, while getting ready to cross back to the US.
Fast forward to returning to the US, we made a stop at Freightliner Great Falls, MT, and had the shop attempt to diagnose the continuing coolant loss, usually 16 to 32 oz every couple hundred miles. The pulled the EGR cooler tube to see if the EGR cooler had a leak and determined it did not.
I once again pressure tested the radiator and cap, and there was no leak down. I also tried to clear the radiator coils from the exposed side with biodegradable solvent and a water hose.
We drove down to Idaho Falls, ID Freightliner and once again had a full diagnostic run per Cummins spec for a coolant loss. He ran a bubble test for compression leaks. No evidence of water in engine oil or transmission fluid. We replaced the low coolant probe, refilled the coolant tank, pressure tested again, turned off the heater valves in case the 40? heater hoses were leaking, and once again went down the road. No leaks or wet spots were observed anywhere during this diagnostic, nor had they been observed at any time previous.
A regen was done in the shop and the tech indicated there was no way we could get those kinds of exhaust temps with a head gasket or cylinder head issue. Every Cummins test on the laptop showed everything normal.
We are now in Gunnison, CO, I am still having some coolant loss, especially after climbing at elevation, and yet the engine temps continue to look normal, sometimes going as high as 217, but always falling back around 210 or below.
Given all of that, I am now suspicious that the one thing that has not changed is the coolant. I went five years on my old coolant without issue, had it tested in the spring at Empire Freightliner in Pensacola (which was before we blew the hose) and in all of that time had used just a little over a gallon over that time period.
Is it possible that coolant is not up to spec even though it was the Freightliner shop?s preference? At this point, it is the one thing we have not changed out. I will tell you that on the last hot fill, the tank gurgled and steamed for almost 10 minutes before I added coolant again. Is it possible we are vaporizing coolant which escapes via the overflow tube and we never see the mist?
I have never been so vexed and had so many people involved and still have the problem unresolved. I have to pull two more major passes this fall, and while I can drop the towed, that may not prove anything.
All told, I am almost $5,000 into this coolant issue without a resolution. Surely, there is a logical explanation somewhere.
I have an open case with Freightliner, but it won?t hurt to get some user experience.
Thanks for your thoughts.
Kim
We have a 450hp ISL 9 Cummins, rear radiator, in our 2012 Thor Tuscany 42RQ. Five years on the road full time and 42,000 miles with zero issues with coolant of any kind.
Coolant is disappearing from my system and Freightliner 24/7 and Freightliner shops have been engaged and we are still struggling to isolate the issue. The story follows and I am looking for any user insight into the issue.
The issue began with a top radiator hose clamp that was loose, forcing a catastrophic coolant loss, and a resulting $1,000 wrecker ride. Farmington Freightliner replaced the clamp, refilled the radiator with Alliance 50/50 coolant, pressure tested the system for leaks and off we went.
Over the next 5,000 miles from NM to Alaska, we would periodically get a low coolant light, stop, refill the tank with the same Alliance coolant, 50/50, and proceed. Over the course of the trip and back, this issue continued to occur, especially on long grades, and ultimately with a stop engine light. During these times, and with a five year history of driving this rig, I never saw abnormal temps, and typically any time temps rose to 212 digital, the fan would kick in, and the temps would immediately respond lower.
Just in case, I replaced the radiator cap with a 16# Freightliner cap after recommendation from FCCC Service, while getting ready to cross back to the US.
Fast forward to returning to the US, we made a stop at Freightliner Great Falls, MT, and had the shop attempt to diagnose the continuing coolant loss, usually 16 to 32 oz every couple hundred miles. The pulled the EGR cooler tube to see if the EGR cooler had a leak and determined it did not.
I once again pressure tested the radiator and cap, and there was no leak down. I also tried to clear the radiator coils from the exposed side with biodegradable solvent and a water hose.
We drove down to Idaho Falls, ID Freightliner and once again had a full diagnostic run per Cummins spec for a coolant loss. He ran a bubble test for compression leaks. No evidence of water in engine oil or transmission fluid. We replaced the low coolant probe, refilled the coolant tank, pressure tested again, turned off the heater valves in case the 40? heater hoses were leaking, and once again went down the road. No leaks or wet spots were observed anywhere during this diagnostic, nor had they been observed at any time previous.
A regen was done in the shop and the tech indicated there was no way we could get those kinds of exhaust temps with a head gasket or cylinder head issue. Every Cummins test on the laptop showed everything normal.
We are now in Gunnison, CO, I am still having some coolant loss, especially after climbing at elevation, and yet the engine temps continue to look normal, sometimes going as high as 217, but always falling back around 210 or below.
Given all of that, I am now suspicious that the one thing that has not changed is the coolant. I went five years on my old coolant without issue, had it tested in the spring at Empire Freightliner in Pensacola (which was before we blew the hose) and in all of that time had used just a little over a gallon over that time period.
Is it possible that coolant is not up to spec even though it was the Freightliner shop?s preference? At this point, it is the one thing we have not changed out. I will tell you that on the last hot fill, the tank gurgled and steamed for almost 10 minutes before I added coolant again. Is it possible we are vaporizing coolant which escapes via the overflow tube and we never see the mist?
I have never been so vexed and had so many people involved and still have the problem unresolved. I have to pull two more major passes this fall, and while I can drop the towed, that may not prove anything.
All told, I am almost $5,000 into this coolant issue without a resolution. Surely, there is a logical explanation somewhere.
I have an open case with Freightliner, but it won?t hurt to get some user experience.
Thanks for your thoughts.
Kim