Reading further in the thread....
If the exhaust system temps are highest at the exhaust outlet, that seems to me to indicate raw fuel being dumped out of a cylinder. It's too rich to burn, and once that cylinder's contents are exhausted out the manifold that raw fuel continues down the exhaust system without burning due to the fuel air ratio being too far off (rich). Instead it evaporates and cools the exhaust system, but heating up itself, past the combustion temperature. Once it get's near the tailpipe, the extra oxygen available there lets it ignite in the tailpipe.
It's essentially turned into a Ford diesel doing a re-gen and turning the tailpipe into a flame thrower.
Earlier in the cycle of this failure, the amount of raw fuel being dumped was less and in that case it was able to burn once it mixed with the other exhaust, likely in the cats, cooking them off and making the funny smell.
IMO this truck is heading for major mechanical damage, if none has been done already due to lack of lubrication (thin oil) or over temperature exhaust. The cats are likely done. Something is leaking fuel at an increasing rate, and eventually you could face a huge backfire in the cylinder or manifold. One that could do serious damage. Even break a crank.
The symptoms and progression of this issue are almost identical to CSFI failure where the injector poppet gets stuck further and further open until it's open a lot, and all the time. leaking fuel into the cylinder. The engine will run rougher and rougher until the big badaboom.
If the exhaust system temps are highest at the exhaust outlet, that seems to me to indicate raw fuel being dumped out of a cylinder. It's too rich to burn, and once that cylinder's contents are exhausted out the manifold that raw fuel continues down the exhaust system without burning due to the fuel air ratio being too far off (rich). Instead it evaporates and cools the exhaust system, but heating up itself, past the combustion temperature. Once it get's near the tailpipe, the extra oxygen available there lets it ignite in the tailpipe.
It's essentially turned into a Ford diesel doing a re-gen and turning the tailpipe into a flame thrower.
Earlier in the cycle of this failure, the amount of raw fuel being dumped was less and in that case it was able to burn once it mixed with the other exhaust, likely in the cats, cooking them off and making the funny smell.
IMO this truck is heading for major mechanical damage, if none has been done already due to lack of lubrication (thin oil) or over temperature exhaust. The cats are likely done. Something is leaking fuel at an increasing rate, and eventually you could face a huge backfire in the cylinder or manifold. One that could do serious damage. Even break a crank.
The symptoms and progression of this issue are almost identical to CSFI failure where the injector poppet gets stuck further and further open until it's open a lot, and all the time. leaking fuel into the cylinder. The engine will run rougher and rougher until the big badaboom.