rivercreek
Member
- 101
- 1
- 18
- Location
- Berryville, VA
Having recently serviced my M923 for the winter season, I was very surprised and disappointed when I pulled my dipstick and found a sloppy chocolate milkshake instead of fresh, clean 15W40 engine oil. My first step towards diagnosis was to pull the oil pan and pressure test the coolant system. As it turned out, I didn't need to apply any pressure to the coolant system to determine what I thought was the obvious failure point. With the oil pan removed, I proceeded to pour water into the coolant system (which was very low due to transfer into the crankcase) and the water immediately began to pour out from the intake side of #5 cylinder liner as fast as I could pour it in. I spent a good bit of time searching different threads on SS looking for wisdom and came to the relatively quick conclusion that it was a failed #5 cylinder liner. I had ruled out a failed head gasket due to the huge volume of water pouring out as fast as it was. There's just no way that that volume of water could make it through a bad head gasket that fast, besides it appeared to be coming out UNDER the piston. Having read a bit about cavitation erosion (something I was not previously aware of), I cursed my ignorance of the importance of checking and maintaining proper coolant PH. Coolant was always nice and clean and green, after all ! I had never changed it or even checked the PH since I'd bought the truck. I didn't even know I was supposed to CHECK the PH in coolant. The motor has a 12/10 manufacture date stamped right on the plate and has only 5,500 miles on it, why waste money replacing all that clean, green, government coolant, I thought to myself. Cursing my luck (and cursing the fact that it just HAD to be the rear head - the hardest one to access, being mostly under the cowl) I went ahead and ordered a complete overhaul kit, deciding that if I was going to have to go that deep into the engine that I would just go ahead and do the whole job while I was there. Once my parts arrived, I tore everything down. I pulled the manifolds, the heads, etc, and finally all 6 cylinder liners, starting from the front. I was very surprised to find absolutally NOTHING wrong with #1, #2, #3, and #4 liners. They looked like new. Not the slightest bit of pitting, nothing! At this point, I began to worry that perhaps I had a more catastrophic problem than I had originally thought. With some anxiety, I pulled #5 liner., hoping to see a catastrophic failure. Still nothing. It was in beautiful shape. Looked like new. I have to admit that at that point, I had visions of a cracked block. I mean, what else could have failed so catastrophically that water was literally pouring out of the block at #5 cylinder as fast as I had dumped it in? Certainly not failed liner o-rings. No way water could have poured out that fast even if the liner didn't have ANY o-rings ! Scratching my head and cursing my luck once again I stood back with disgust thinking how much work it's gonna be and how much money it's gonna cost to replace this entire motor. As I stood forlorn and frustrated in my shop I wandered over to the heads I had removed earlier - still covered with chocolate milkshake - and stared at them dejectedly and with no real purpose. My friend who had been helping me with the tear down stood there beside me staring at the heads also, with no real purpose either. After a few moments, he said quietly and without expression: "There's your problem." I looked at him and he looked at me then down at #3 head again. I looked and still didn't see anything but a head covered with chocolate milkshake until he bent down and stuck his finger through the hole that should have been filled with a freeze plug. I walked over to the oil pan (the VERY first thing I had removed a week prior - still sitting in the corner, still with about 2" of chocolate milkshake in the bottom of it and proceeded to dip my hand in the mess and feel around. Lo and behold, I pulled out a freeze plug the EXACT dimensions as the missing one. Not a scratch, not a speck of rust on it, just very slightly egg-shaped.
I had just disassembled the entire top half of the motor to replace a .79 cent freeze plug that I could have replaced by simply removing a valve cover. Wow. I think I was more pissed off about that than the thought of replacing the entire motor, to be perfectly honest. I did end up replacing all the liners, the pistons, the rings, the main and rod bearings anyhow. With it this far down already and the whole kit sitting there on the floor, why not? That's the story, front to back. I thought that I would share the lesson I learned and suggest that any other SS members who find their crankcase full of chocolate milkshake not jump to conclusions as quickly as I did. I never have found any other threads on SS that point to this being a possible failure point, so hopefully this willl save someone the tremendous amount of time, money and frustration that my lack of attention to detail cost me. Silver Lining: I did get the whole job completed several days ago and she's running better than ever. With an oil pan full of beautiful CLEAN 15W40 Rotella. Morals of the story: 1). Coolant in your oil COULD be a .79 cent/ one hour repair. 2). Check the contents of your oil pan carefully BEFORE you completely disassemble 3/4 of the engine it was attached to. Hope this helps some other poor soul in the future...
I had just disassembled the entire top half of the motor to replace a .79 cent freeze plug that I could have replaced by simply removing a valve cover. Wow. I think I was more pissed off about that than the thought of replacing the entire motor, to be perfectly honest. I did end up replacing all the liners, the pistons, the rings, the main and rod bearings anyhow. With it this far down already and the whole kit sitting there on the floor, why not? That's the story, front to back. I thought that I would share the lesson I learned and suggest that any other SS members who find their crankcase full of chocolate milkshake not jump to conclusions as quickly as I did. I never have found any other threads on SS that point to this being a possible failure point, so hopefully this willl save someone the tremendous amount of time, money and frustration that my lack of attention to detail cost me. Silver Lining: I did get the whole job completed several days ago and she's running better than ever. With an oil pan full of beautiful CLEAN 15W40 Rotella. Morals of the story: 1). Coolant in your oil COULD be a .79 cent/ one hour repair. 2). Check the contents of your oil pan carefully BEFORE you completely disassemble 3/4 of the engine it was attached to. Hope this helps some other poor soul in the future...
