Quote:
Originally Posted by wbradley
Id be interested to know if there have been confirmed documented cases of a DI sticking open and completely filling a cylinder, resulting in hydrolock in other vehicles. Is open a grounded live circuit activated event? Can that even happen with the ignition swich off? The DI atomizes the pressurized fuel so how fast could it fill? Could the line pressure (up to say 1500 PSI) in the fuel system push out enough fuel? Also, for an injector to open electrically, does it not need to be powered the whole time? Could Techstream detect any artifact of this occurrence? Could a car with zero coolant in the engine just have bent a rod from heat after a while and still not show any other clear indication something was wrong before this incident?
The OP for sure has a fight on his hands. Good thing there are lots of salvaged twins, perhaps if there is no remedy here, think about locating a capable Subaru independant shop and a motor. People here will find you a motor, I bet. This will be a 5-6K hit but if you keep the car a year or two longer than you might have it will even out in the end. Hopefully you have access to the funds, credit or otherwise.
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Digging around yesterday (it was a really slow day for me) I found that the default for the injectors is of course closed. I would be exceedingly rare to fail open but rare does not mean can't happen. Since the system is very high pressure and that pressure is not relieved when shut down it could indeed force fuel through a stuck injector. It would not last long as the pressure would drop fast but it could. The only thing I could not find was the volume of the combustion chamber and that was provided. Since it is only 40 cc and you don't have to fill the whole thing for hydro lock I think the theory is sound. Probably a one in several million chance but reasonable.
The over heat of course is possible as well but to have no signs of heat anyplace else would be even greater odds than a stuck injector I would think. An engine overheated enough to bend a rod would almost certainly be easy to spot right away. I have not watched the video (probably should have and will) but an overheated engine usually makes a very distinctive sound ( heard it way to often) and there should be steam coming from someplace even if almost dry.
One thing we do not know is the condition of the rod connection to the crank. I have seen those let go, rod go off center and top out the cylinder bending the rod. Those usually showed clear mechanical damage where it hit though. Oh and that was on oid school big blocks so not even sure it is possible on a boxer.
With the info we have my money remains firmly on the most unlucky fuel hydro lock in history.