I own a few detroit two strokers and looked a machine today with a 3 53 in it. When I cranked it over, it sounded like it had a bad valve in it and weezed and hissed as it cranked, never heard that before on any of my other two stokes before, at idle it ran rough and sounded like it had a miss to it, not sure how thats possible with an two stroke but at wide open it ran good. Would it be a fuel problem or what would cause it, how serious is it and what would it take to cure it. I haven't bought the machine yet, but am thinking really hard if this isn't going to cost me a vast fortune to fix once I'd get it home. Any ideas or suggestions?
A bad valve, bad valve seat, bad piston rings, or bent connecting rod will typically (but not always) cause a noticeable different sound when cranking, one piston stroke will cause cranking to "speed up" then slow back down when other (good) pistons come on compression stroke. Not sure about the wheezing and hissing sound, could be bad valve or bad valve seat. Either of those would affect compression, causing a miss at idle speed, but at full load RPM be not so noticeable. As for whether or not to buy the machine, what's the rest of the motor like? Is it covered with oil from many oil leaks? How much blow by pressure when oil cap is removed? Excessive leaking from air box drain tube? Does it fire right off or does it have to crank for a few moments? A reman head with valves and springs will be 1500 to 2K. Head gasket set, maybe 50 to 100 bucks. Single piston kit minus connecting rod, maybe 2 - 300 bucks. And you would need ring compressor if it needs piston/rings, injector timing tool for head replacement. And it you already own some "Green Leakers" you prolly already know not to use 15W/40 multi grade oil.
I have a 353 in a welder that ran like you speak of,,,,, the rack rod to one of the injectors was binding... reset the rack and she run like a swiss oil leakin watch...
How in the hell did you come up with that? You've spent way too much time around OCR.
I had a 3-53 turbo that ran like that and had that same hissing. Mine had a cracked head.
Cracked head is not uncommon with a Detroit oil leaker, especially if you overheat them. Very bad to overheat a Detroit. :nono
I've never had a two stroke apart before or ever seen one apart so I have no clue what they look like inside. So it could be cheap to fix, or about 2-4 grand. As for the rest of the motor, it started hard, in 70 degree weather we had to give it a shot of either,but was working with a very weak battery too, I mainly thought it was battery related myself, but the owner said it hadn't run much in years, only to move it basically. It smoked a lot of blue, never really cleared up even after we ran it for about an hour, which I thought was a bit long to smoke blue even for a detroit. No extreme blowby out the oil fill or dip stick I didn't think compared to my others, about the same. As for oil leaks, it was a two stoke detroit, I was told to never worry much until it quit leaking oil, then it was out of oil, but seriously it had about the same oil leaks as my other detroits, nothing dripping or huking and puking anyhow, just some seeps here and there and wet on the sides of the engine. It looked like the valve cover was leaking somewhat, and it had fuel leaks as well to add to the confusion, but overall it wasn't bad, but again I don't know if its had 10 hours on it since it was steam cleaned off and has been sitting in the back of a shed or 200 hours since its seen a good bath, or if its ever seen a good bath, this owner has it only about 4 years and put maybe 50 hours on it is all he claimed. By the looks of the rest of the machine, it hasn't been run much lately that's for sure. I'm not a major fan of the two stokes, but I'm not sure the machine is worth putting a cummins or deere engine it its place. I know it can be done but before I'd spend 2-4k on a detroit I'd swap it out and do something different, the machine is underpowered the way it is, most had 4-53's in them, I always though a four cylinder cummins would be much better myself. Then they'd start at least in cold weather. Thanks for the reply's guys it at least gives me something to think over.
Yes,,, yes OCR coached me!!!
Randy,,,, you can pull the valve cover off, loosen one injector rack at a time and speed that injector up,,, that way you can tell which cylinder is giving the grief....
That would work. I typically take a big flathead screwdriver, push down on the cap of the injector while engine at idle, prevents rocker from firing injector, sort of like pulling a plug wire off a gas engine.
Thanks guys, it give me something to look for and test to see if its fuel or something worse.
you can perk it up if you have to rebuild it by using the highest compression liner kits, making sure the cam is on advanced timing and free flowing exhaust, N50 injectors . It sounds like it is just tired. and they are still cheap to overhaul if you can do it yourself. When I worked at Evergreen I did at least 50 of them, they were in the air cargo loaders. Also on the overheat issue, a Detroit head will crack in 30 seconds if the fire deck gets uncovered by coolant. That was in a manual I read somewhere. Oh and 2 strokes and most other diesels, rely on correct cranking speed to start, 250 rpm or more on a detroit