losing coolant, no leaks or white smoke

nate.mchugh1986

New member
Mar 19, 2016
25
0
1
maine
last weak I blew the side of my radiator out. Tonight, new radiator is in, 5 gallons of coolant, drained the oil, no coolant there, 10 quarts in, time to fire it up. Starts up no problem, no white smoke, no loss of oil pressure, no leaks. I let it idle 20 or so mins, put her in retreat, no issues, put it in drive, and it bellows black smoke, and has no power. I repeat this, this time, it stalls out. I crank it 15-20 seconds, finally it starts, let it idle for 5 mins, repeat, same effect. Repeat the starting process, 25-30 seconds before it fires this time, and low coolant and no oil pressure. I get out to look, no leaks anywhere. I cant get it to a garage as it is, and im currently in arizona, but from maine. Anyone have any ideas? I've done the headgaskets before, but there was white smoke. The person im staying with said i gotta be out in 11 days, truck running, or not. I need some ideas!!
 

2004LB7

Well-known member
Dec 15, 2010
6,988
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Norcal
Does it rev up fine before putting it in drive? Does it drive normally in reverse? Rag left in the intake?
 

nate.mchugh1986

New member
Mar 19, 2016
25
0
1
maine
It lost ALL oil pressure? is the oil and coolant the color it should be?


Okay, so its not losing all pressure, drained the oil i put in the other day, and it was as it should be. I think the coolant loss was just filling all the gallies.
When I put it in forward gears, it puts the truck in limp mode and causes a stall out, but i can reverse with no issues. I replaced the neutral safety switch less than 10k miles ago, and although it is going into limp mode, it is nothing like when that happened. When I go from reverse to drive, there is a LOUD clunk, and as soon as i apply throttle, it imidiately goes into limp, and then heads to the stall out. I think my Allison has quit. But the fluid is perfectly cherry red and where it should be. So im trying to figure out the best way to trouble shoot what is happening. Any advice here?
 

dndj

Boost!
Apr 13, 2019
302
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Oregon
Possible fried TCM? If memory serves, touching the heat sink case of the TCM to +12v or ground could cause traces internally to burn up. Given the radiator repair, I'm assuming the TCM was moved around, possibly touching something accidentally?