Jim Warman Posted September 9, 2007 Share Posted September 9, 2007 Back on the 28th I'd mentioned that we had a hydrolocked 6.0 in need of an EGR cooler.... Tech got the deed done and, after much cajoling, I convinced him to drain the oil pan, take out the GPs and bump the starter.... "With no oil?"... "what would be the difference between this and a cold start?".... Anyway... we finally nursed this thing to life... one of the more interesting ones that I've seen since the cylinders came "online" one at a time and after many starter cool downs. Tech ran the thing to operating temp, checked for leaks and went for a road test.... back almost immediately with a horrendous vibration coming on about 3K rpm.... WTF? Bent rod? Then came the realization that Bambi had his face planted firmly in the radiator at one point - sure enough, the water pump shaft is bent.... The question... how many bent rods has anyone seen on these due to hydrolocking? Does that itty-bitty starter have the low rpm grunt to hurt parts on a regular basis? I know there's got to have been times that most of us have gone into the back lot, keys in hand, not expecting that "whirrr... grunt" that has us find someone to drive the push truck.... I *may* have done it a time or six, myself.... Quote Link to comment Share on other sites More sharing options...
Aaron_Johnson Posted September 9, 2007 Share Posted September 9, 2007 I have yet to see one of these bend a rod. Even back in the day with the 7.3 when changing an injector they told me you could bend a rod when changing an injector.If a hole filled up with fuel, oil or coolant when driving down the road I could see it bending one, but I wouldnt think the starter would have enough power. When we get them locked up because of coolant, all I do is bar the engine over backwards 2 times, then no need to pull the glow plugs. Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted September 9, 2007 Share Posted September 9, 2007 I don't like to crank them when I know they are hydro-locked... but I've seen guys do it with 6.0s and 7.3s with no ill-effects (that we are aware of anyway). I do however remember in CAT training, we were told that if an engine is hydro-locked, and you get it to turn over, you HAVE damaged a rod. Symptoms may not be evident right away, but will likely appear. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 9, 2007 Share Posted September 9, 2007 Well, many times there have been engines hydrolocked that you were unaware of and these are typically caused by EGR coolers as we well know. I also have never seen any ill effects of bumping the starter once or twice during this condition. If you recall my posts on the EGR cooler that filled both exhaust manifolds and poured out the exhaust, that engine was bumped quite a few times. It left running okay... I think. You see, it returned a few days later with a bad miss and is still in my shop as we speak. I did not work on it so I cant verify how it ran when it left. Long story short, it was missing badly in cylinder #7 with codes for 7 & 2. I could only verify #7 so that is all I went after. First thing in the morning I will recheck my work before releasing it. The reason I bring this up is that relative compression showed nothing that might indicate an issue worth digging deeper. Do you think it is possible to damage an injector by bumping or cranking an engine while hydrolocked or with coolant in the cylinder? This one certainly makes me suspicious. Quote Link to comment Share on other sites More sharing options...
GregH Posted September 9, 2007 Share Posted September 9, 2007 The way people operate their trucks around here, we only get them once they're trashed enough to be hydrolocked... All I've ever done is bar them over, or hit the starter a few times (if the hydrolock isn't too bad), until they will turn a few rev's without assistance. Fix the cause of the hydrolock, and take it on a good test drive to get the exhaust clear and the cylinders sealing again. No bent rods, damaged injectors, or anything else yet... Knock on wood... Quote Link to comment Share on other sites More sharing options...
HGM Posted September 10, 2007 Share Posted September 10, 2007 I can say without a doubt that I have seen it.. One in particular was an engine that bent #8 while running due to a loose injector. The tech put the new short block in along with the newly sealed injectors on the left side only to have a slow crank ( at first).. It seems the previous tech not only left #8 loose, but #7 as well(the tech didnt think to check them while he was there, you know, "flat rate")... After this slow crank, it ran with a miss.. #7 rod on the new short block was now shorter than the rest.. Be carefull..... Quote Link to comment Share on other sites More sharing options...
DieselD Posted September 10, 2007 Share Posted September 10, 2007 Almost 75% of the coolers I get are hydroed. seems fleet customers dont stop for anything until it wont run any longer. even with an extreme overheat. Just keep filling up the coolant it will be fine! anyway Ive never had one bend a rod. Ive even bumped it by the starter enough to free up the engine. Im sure there is always the one out there tho. I have seen a guy working on 7.3 do it. Quote Link to comment Share on other sites More sharing options...
HGM Posted September 10, 2007 Share Posted September 10, 2007 It may simply be the "bumped it" action rather than holding the key in the start possition that makes a difference.. /forums/images/%%GRAEMLIN_URL%%/shrug.gif Quote Link to comment Share on other sites More sharing options...
slim Posted September 11, 2007 Share Posted September 11, 2007 We do RAV's in our area and a couple years ago when we were getting like 5 a week another guy in the shop pulled one in that had been towed from another dealer not running. It would start up and stall-more like lock up. He found a loose injector that after clearing all the air from the fuel rail by cycling the key it would start but would suck so much fuel in the cylinder it would hydro lock. As far I know he put a new injector in it and it ran fine when it left. Probably lucky but I know those powered metal rods are plenty strong and overall the bottom end of the 6L is as good as any other motor. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted September 11, 2007 Author Share Posted September 11, 2007 And the really sad part is that, last time I checked, Ford insisted we remove both injectors and glow plugs for cylinder head R&R.... My guys don't.... Quote Link to comment Share on other sites More sharing options...
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