WildernessJeep
Active member
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- 28
- Location
- Huntsville, Texas
I got the M936 about a month ago and changed all fluids and filters upon arrival. We drove it around the neighborhood a few times with no problems. I even got to use the crane a couple of times! Then I took it on a 5 mile highway trip, going about 55 mph (not floored). About halfway back, I got a "pow" and noticeable louder engine noise. All gauges remained within limits, and I drove it home several miles (taking it even easier). Upon return, the motor oil was PLATINUM!!! That's a great bonus. My engine had about 10 gallons of gray sludge where the motor oil was supposed to be.
Truck sat a week, waiting on my schedule to clear. I moved it to the shop with my drop deck 18-wheeler, so no engine start with the sludge. Here's my remedy thus far:
1) drained all the motor oil, I got about 10 gallons of platinum sludge. PLATINUM!!!
2) drained the engine coolant, I only got about 2 gallons of coolant out. The coolant was clearly mixed in the engine oil.
3) put 2 gallons of diesel fuel in the top of the motor, twice. Each time I got even more platinum out.
4) changed the filter. More platinum.
5) put fresh motor oil in the engine. Because I haven't fixed the cooler yet, I did NOT put more coolant in the engine.
6) started the engine without problem (some white smoke). have only run it for a few minutes since to diagnose the problem and to flush the fresh oil (hoping to resolve the clacking).
Following those remedies, I still have milky oil and a loud clacking sound. It really makes mechanically minded people wince. It sounds like a clacking in the middle cylinder. No loss of engine power (I haven't been beyond an idle since). The gauges read normal, but oil pressure is high at about 100 psi. Clearly the motor oil and coolant had mixed thoroughly. Based upon the suggestions in the forum, I think it is the oil cooler, so I ordered a new one, and will install tomorrow. I'm still getting the sick "clacking"sound and a ton of blowby, which was specifically not present prior to this issue. I have some white smoke from the exhaust, and can clearly hear one of the cylinders "ain't right" at the exhaust pipe.
To further diagnose, I:
6) pulled the head covers, they were full of platinum, so I cleaned each in a parts washer and poured about a gallon of fresh oil down from the top. More sludge from the bottom came out with a fresh engine oil change.
7) Ran it for about 5 minutes, diagnosing the headers, then changed the filter and motor oil again. The engine oil is now more of a milky substance, not the gray mud I started with, but not clear caramel either.
I still have the clacking sound, and the oil is gray again, but seems to be more viscous. I'll change it again tomorrow. I'll also scope the bottom half of the motor through the drain plug hole to check the lifter bearing and cam, as available.
So now my questions:
a) what's the best way to truly clean out this engine? I can drop the oil pan and clean out as much as I can reach, but I wanted to spray something up from the bottom to clean it well. What cleaner should I use to clean the old oil out, but not scar the engine and bearings? Someone mentioned Seafoam, but for that, I might as well use diesel fuel. I was planning to use an aerosol something, but what?
b) what's the clacking sound? I thought it would be a bent lifter, but they all look good, and each has a good waterfall of platinum cascading in the video. Pushing down on each lifter during idle, they all feel about the same. The sound is really mid-engine, well below the header rack. See video attached below.
c) what other steps should I take after introducing 6 gallons of coolant into my engine oil? I've flooded other vehicles before, but those were hydrolocked gasoline engines (just pull the plugs and turn it over with the starter a few times). What do I need to preserve the longevity of this engine?
I've researched the manual, and it doesn't say much about remedies, only how to change out parts. You guys are my go-to source on this!!! Thanks in advance!
