pcassidy111 Posted September 13, 2007 Share Posted September 13, 2007 Working at an independent I jump at the chance for diesel training, especially when it is given by the local Ford troubleshooter and ‘diesel expert’. I was quite disappointed with the information given, didn’t seem to know his product very well or else he is not a good tech. Reason for the post is I need some help from those of you on the front line to help separate fact from fiction regarding the regeneration process on the 6.4L He related a story of a customer who used B99. It caused the PCM to command regeneration of the particulate filter so many times in 1000 miles that the crankcase filled up with fuel, raising the level so the ‘PCV’ system sucked oil into the cylinders, hydrolocking the engine and bending 5 rods. I understand that the regeneration process could allow some raw fuel to bypass the rings, especially on a new engine, and dilute the oil but this story seems a little far fetched. Assuming the customer didn’t notice a smoke screen behind his truck and possibly a vibration from the crank and rods moving through the oil wouldn’t the engine ‘runaway’ before hydrolocking due to the unmetered fuel/oil mixture entering the cylinders? Is the ‘bullshit meter’ pegged on this story or could it happen? Thanks for your time, Pete Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 14, 2007 Share Posted September 14, 2007 Sounds to me like you figured out this guy is full of it. All kinds of strange things happen to these engines but this sounds unlikely to put it kindly. During regeneration, a small amount of fuel is injected during the exhaust stroke as it exits the cylinders. This atomized fuel saturates the exhaust gasses with unburned hydrocarbons that ignite in the catalytic converter and the DPF to create the heat needed to incinerate the collected soot. I am not an engineer but I believe this process uses a very small amount of fuel in relation to what is injected during the power stroke. Given the timing and volume of fuel involved I do not think this process would wash the cylinders and dilute the oil with fuel. What IS possible is that the common rail fuel injection system being inside the engine could leak fuel into the crankcase and "make" oil. There are probably notable symptoms caused by that. This type of failure is possible and has already happened. I recall GregH pulling his hair out on one such concern not too long ago. Any way, you mentioned high crankcase oil levels and the symptoms of that happening and you are correct. At some point the engine would fail to run long before the oil level could possibly get high enough to do what was suggested. There are many other things that would happen long before and as you stated there would be very noticeable symptoms like engine vibration, lack of power and who knows what. Turn your BS meter off before it over heats! Quote Link to comment Share on other sites More sharing options...
DwayneGorniak Posted September 14, 2007 Share Posted September 14, 2007 I agree with you Keith. The bullshit is real thick with that story. Could be a high pressure fuel leak under the covers. Could be bad injectors. I am starting to see problems with these injectors. I have one in the shop right now with a melted glow plug and piston on cylinder number 2. Crankcase is overfull by almost five inches. DPF is hooped from oversaturation. The oversaturation of the DPF is what would cause the DPF pressure sensure to sense increased pressure in the exhaust and cause the truck to go into regen continuously. Quote Link to comment Share on other sites More sharing options...
Cetane Posted September 14, 2007 Share Posted September 14, 2007 I am going to tread a dangerous line for me on this one but here is my take on that story. Hypothetically the ECM knows exactly how much fuel is injected during regen(assuming a mechanically sound fuel system), with this info it is plausible there could be some kind of calculation in which the ECM would "know" the amount of oil dilution based on a predetermined model. Therefore it is possible that the computer could then limit the amount of total time the truck is in regen to avoid such circumstances. If I were to assume the above statements were correct I would have to call BS on this one if the storyteller totally attributed the engine failure to regen. That being said there are alot of variables(electronic and mechanical) that could allow that to happen, I havent seen it, but I have learned to never say never. As for the amount of fuel dumped during a regen, you might be surprised at the quantity allowed, obviously it depends on speed/load and the exhaust temps but the amount can climb pretty high in relation to the "normal" injection events. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 14, 2007 Share Posted September 14, 2007 I have learned to never say never. Good thought and something to remember especially with a new engine and new systems we have no experience with. But even with the possibility of the fuel system dumping fuel into the crankcase I would think that something else is likely to cause a catastrophic failure or at the very least a shut down before the oil level could get high enough to get sucked into the intake. I know. Never say never. It makes sense that the PCM would know how much fuel is being injected for regen and I am sure there would be limits set for this. Now I agree that this designed to protect the engine provided there are no mechanical or injector issues that could allow something to go very wrong but even during normal operation? The only thing we were are told about this is that it happens during the exhaust stroke and that is why I think it would be unlikely that fuel is collecting in the cylinder(s). Right? Wouldn't you think that the exiting exhaust gasses would take all (or nearly all) of that with it on its way out? Sorry guys if I am rambling, I am trying to make sense of this specific action. Quote Link to comment Share on other sites More sharing options...
Cetane Posted September 15, 2007 Share Posted September 15, 2007 Wouldn't you think that the exiting exhaust gasses would take all (or nearly all) of that with it on its way out? The key to that statement is nearly all. It reminds me of the old trick when EEC-IV first came out. People would put in really cold thermostats or fool the ECT and cause cylinders to eventually wash out due to an extended rich condition. It wouldnt happen in a few miles and I guess that is my point. Most of the fuel is expended but some sticks to the cylinder walls and makes its way to the pan. Eventually you would see the effect but it would take a long time. That is why I think this is either an untrue story or at least not the underlying cause. As for the specifics on the regen, I wont say anymore but maybe you should record an injector current trace and watch what happens as the regen progresses. I think you will be surprised. Quote Link to comment Share on other sites More sharing options...
WGLR13MWZ Posted September 15, 2007 Share Posted September 15, 2007 Quote: local Ford troubleshooter and ‘diesel expert’. Were these people from the dealership or Ford? I would say the story is far fetched. Quote Link to comment Share on other sites More sharing options...
HGM Posted September 15, 2007 Share Posted September 15, 2007 I believe another key to this story is the bio diesel.. Not saying I buy into the hydrolock condition from a regen though. With any fuel and potentially more so with bio, it could be an incomplete burn leaving more unburnt fuel behind. With more fuel left behind, you would have more of a cylinder wash potential along with DPF clogging. With the DPF becoming more restricted causing regen (overfuel), poor fuel burn and cyl wash causing blowby and oil level growth, who knows how bad things could get.. I think the guy was reaching a bit with this diag, but, I dont know... Bottom line, these guys need to start running the trucks with design in mind. They have been tested with USLD and DPF's, the guys who leave well enough alone and just drive the trucks as designed will have much less trouble out of them.. No different than the 6.0L.. Just thought Id throw in my $.02 Quote Link to comment Share on other sites More sharing options...
Torqued_Up Posted September 15, 2007 Share Posted September 15, 2007 The comments about the biodiesel reminds me that we have never really discussed bio here unless I missed the post. Itsh hard to find any accurate informationand Ford tells us nothing other than no more than B5 is acceptable. Quote Link to comment Share on other sites More sharing options...
HGM Posted September 15, 2007 Share Posted September 15, 2007 In short, you dont know what you're getting... It could be soybean-chicken fat(used or fresh).. Too many variables. May be a fair option in the future, but we arent there yet. Filtration is apparently one of the biggest issues with it right now. What works for one type may not work for another.. I havent found much good info on it either, but that about sums up what I do know.. Quote Link to comment Share on other sites More sharing options...
pcassidy111 Posted September 18, 2007 Author Share Posted September 18, 2007 Quote: local Ford troubleshooter and ‘diesel expert’. Were these people from the dealership or Ford? I would say the story is far fetched. FOMOCO troubleshooter and trainer. Quote Link to comment Share on other sites More sharing options...
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