Check It Out

[qmp312]

Just want to share my experience with my 2011 prostar cm871. Keep in mind I'm a gas gear head still learning about the diesel. It all started about 2yrs ago when I was sitting @ a truck stop looking @ the load boad for a load & a guy comes by & says hey man your leaking coolant. So I check it out & found what I thought @ the time was the top radiator hose leaking even though I knew the hose was only about 2 yrs old I changed it (I had a spare) & went on my way. To my surprise I still had a leak which turned into a much bigger problem. After chasing this leak all over my cooling system it became evident that something was putting excessive psi into the cooling system. Like I said it started with a hose then hose clamp then the tank on the radiator then the oring on the water pump then the compressor and finally stopped @ the radiator cap. The excessive psi found the weak points within the system. I also had a failing clutch fan that was causing slightly higher than normal operating temps. My thoughts were @ the time was an air pocket in the system since I had been into it a few times but after serveral attempts to remove it ie; pulling a vacuum on the system pulling the bleeder plugs in the system while @ operating temp in an effort to get the air out it, it was still the same. Myself being burned too many times by stupid incompetent techs I had to figure it out myself. I had about 750k on the engine @ the time so it was time for some component failure like the clutch fan & the compressor even though it was still working as advertised I don't regret changing it. However while doing some research on this issue I kept coming arcross a head gasket or head failure. Being a gas guy & not understanding the diesel I disregarded this possibility because I didnt have any of the typical signs of that kind of failure ie; coolant in the oil, oil in the coolant, white smoke on the 1st start of the day, loss of power & mpg etc. So I fixed my failed components & continued running the truck gradually adding coolant to system. When I got to about the 930k mark I was blowing out about a gallon of coolant a day out of the radiator cap. I then brought the truck home & rebuilt the engine. While inspecting the head I found cracks on five of the six squelch areas @ the injector. I'm sure with the head cleaned up & checking with either magna flux or pressure checking several more cracks would be visible, but the head gasket only had a small area breeched between 4 & 5. So obviously the cracks in the head was the cause of the excessive psi in the cooling system. Not sure exactly what caused the cracking, I've always been very gentle with the truck not putting to much stress on it. The key things I learned from this are 1) to know your equipment and to understand what is normal operation. When something doesn't look right search for what's wrong until you find it & fix it. If it turns out to be something major and you don't have the $ to fix it understand the risks involved in continuing to run the truck before you do. It could cost a lot more or worse put you out of business if you don't. 2) The other thing is how forgiving the engine really is. It was diffently the wrong thing for me to do by continuing to run the truck for as long as I did. I got really lucky in that the engine didn't hydraulic & push a rod threw the block or break the crank which would have cost a lot more $. And looking back on the experience I see how stupid I was by not doing a simple combustion gas test which would've indicated the failed head. Instead it cost me extra $ and time by chasing the failed components caused by the head failure. So lesson learned be methodical in your trouble shooting & don't stop until you find it & fix it. It will save you money in the long run