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Discussion Starter #1
I have the 6.2 GM in my truck and it has a problem. Here is the background story. When I got it the truck it was weak, very slow compared to other trucks with the same armor etc. A group of competent mechanics took the truck and made it run better. For the last 6 months it has run great only a few suspension issues but nothing with the motor. Well about three weeks ago we went on a long drive. When I got back it was idling rough, very rough and some noted power loss. I went home on leave and when I came back my guys had just got back from an even longer/harder drive. It was idling so low/like crap it couldn’t run with the a/c on and not moving. It could barley reach 20mph. I changed its air filter, fuel filter, ran that tank out and added fuel from another source to it, etc. Nothing helped at all. Our mechanics here “Fixed it” but turning the idle back up (? Now it idles way to high) and messing with the fuel injector pump. Its now burning thru fuel like crazy, smells horrible (fumes), idles like it has a mild cam, and still doesn’t have much power even with the extra fuel. Any ideas on what could be wrong with it? I don’t want to loose this motor on the road. Our “mechanics” say there is nothing wrong with it. I don’t believe them. The parts they have changed are the fuel pump and fuel injector pump. I think its about to go. I am guessing burnt exhaust valve or valves because of the sounds it is making along with the loping idle. :ermm: Anyone wanna take a guess at this thing?

[Edited by WytchDctr on Oct 27, 2005 10:10 PM]
 

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Does it have a cat converter? might be plugged.. I know the newer ones do. Or else a exhaust restriction.. Maybe you have a potato stuck in the tail pipe? :eek:
 

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I dont know for sure about yours, but we have larger trucks at my job, they have supercharges that are invreted, they are used to suck out exhaust gases, when the belts break, or they need oil, the things run like sh!t. make sure your intake pipe is clean too, and no leaks. its not turboed is it? dont think any of that will help. but i dunno. if i was you, id get a highflow exhaust, diesels come alive then
 

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To clarify is it a true M1114(turboed) or a M1025 with add on armor that we are taking about?
 

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Have they checked out the heater plugs, and if the engine has a seperate diesel pump like the big trucks do, you might need to take a look at the timing of it as even being a tooth out or having one valve a small degree out of cycle it compounds the problems at the engine. Hows the ignition?
 

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Discussion Starter #7
The glow plug system just now going fixed. I did that after the mechs couldn't. Still checks out normal. That system shuts down about 2 min. after it gets running. The fuel pump and injector pump have been replaced and turned up. Its running soooo rich right now you can't stand on the drivers side of it without getting sick from the diesel fumes. This fuel is giving it just enough power to make 50mph.... before it couldn't do that after whatever broke, broke. Before the breakage the truck could do alteast 65mph (GPS said so ;): ) I am thinking valvetrain is screwed up.. but thats a guess.
 

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hows the compression on it...
 

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6.5 it. Sounds like the compression is shot. Cause, they are at like 20:1 or some crazy high sh!t. Make sure the gaskets havent blown, or the head is tourqed down all the way... i dunno.. i'm at a loss.
 

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Yea its sounding to me like a compression issue, either valvetrain related, or piston issues.
 

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Discussion Starter #12
http://www.diversecultures.com/other/army/PA310001.MOV

Sorry for the bad sound. This was taken with a small camera not really ment to take movies. You can barly hear what I am talking about, the plopping. You can however see the smoke. That didn't happen before whatever happened to the motor occured. Also this is with a warm truck (drove it that morning), with DF-2, and it was already over 70 degrees. So its actually on its best behavior. Ill try and get a video of it at its worse and post that.
 

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I drive a truck at work with a Detroit Diesel 8.2L NA diesel V8, mated to an Allison 4 speed auto with 4th gear blocked, it's a spotter, not meant for the road.
Don't know much about it, but I've been driving it everytime it breaks down. It's on its 3rd engine now, and I know the smell your talking about, smells like really hot metal and diesel.
We drove it around with rod knock for 6 months, and finally it punched through the block. Plus it runs like your truck is in the video when it's cold, and I mean cold like under 50 degrees.

They need to check the compression on that thing, I bet it's a bad ring from looking at that video, or a burnt up valve. I've seen enough blown diesel engines, just don't know much about them.
 
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