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Lds-465 Engine Knocking. AGAIN

Oerthedge21

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As some of you may remember I had a fairly long bread running back in the summer of my rebuild on the lds-465 in my Deuce. Welllllll, this truck just loves to test me, and here I am again with similar symptoms as before. I put all new pistons, rod bearings, gaskets, and injector nozzles in, and had the injectors pop tested and rebuilt/reacilbrated along with the new nozzles installed (2 hole). Thing ran fine after that, had a weird ticking/ knocking after the rebuild but it went away after a hundred or so miles. I used John Deere break in oil for 500 miles then changed it out for rotella 15w-40 with a proportianate amount for zinc additive. Well here we are, about 700 miles later, and the knock has returned. Its fairly subtle, not s loud as it was way back then. Truck has 40 psi hot for oil pressure idling, 60 when you're on the throttle. Stays at 160° no matter what. I've only run pump diesel through it with a fuel additive that has lubricants and injector cleaners as well as antigels in it. I noticed today the truck seems to smoke a lot, like it did back when the injectors were all leaking. Not quite as much, but still noticably more smoke than it was making right after the rebuild. I pulled the oil cap, and attached is a video of what it looked like. You can feel the gasses pulsing out the valve cover. Smells entirely of engine oil mist, no exhaust or oil burn as far as I can tell. Oil itself is still pretty clean, not coal black yet. I'm really getting to the end of my rope with this truck. I love it and all but I don't think I can bring myself to take the heads off the thing again, at that point I may well sell it. Any suggestions bon what to do or what could maybe be my issue here? I'm really praying I didn't melt another piston.

 
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Menaces Nemesis

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They tend to be noisy and can be "gassy" too. Sounds fine to me. You hope you didn't melt another piston? what does your EGT read under steady load? Doubt it'd run too well with a ventilated piston, or that you ruined one staying under 1250* Yeah, you've got some significant blow-by... lots of us do and survive just fine. Take the compressor belt off, then see if it still blows as much. As I said in your last thread, if the compressor piston/clyinder is worn it can allow air to pass by to the compressor base, where there is a path to the crankcase via lubrication passages, thus charging the crankcase with air. How does the truck run? Even if you see no change in blow-by with the compressor belt off, and it still runs okay, remember what I repeated from a couple of sages here on SS regarding blow-by in your last thread...

"If it does not use or lose oil, don't worry about it" - Doghead

"If it's not consuming oil, it's not worn-out" - Will Wagner


I understand with all the work you've done that you want it to be perfectly tight and purr like a kitten. But, honestly, I think you're digging and perceiving things that aren't necessarily problems unless you make them out to be. If it's running good and not consuming oil, drive it! enjoy it!
 
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davidb56

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Mine "ticked" so bad I did a valve clearance adjustment. Still makes noise. leaks oil, gear oil and a little air. I keep up on topping things off and use fuel additives, change oil and have done a coolant flush. Now I just drive it and ignore the noises. My take is ........wait until something really develops.
 

Oerthedge21

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Ah yes I had forgotten about the compressor being an issue. My big concern was just that it suddenly seemed different. With two ton in the bed it cruised about 750-800 at 50. Yesterday it was more around 850-900. I'll try to screw around with it today but I'll probably be at work until after dark so maybe this weekend
 

cattlerepairman

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Oerthedge21, I rebuilt my LDS as well. As opposed to you, I kept my liners (honed them) and my pistons (new rings). All new bearings. New heads. Initially, there was zero blow-by. After the break-in period (same technique as you used) and a good 1000 km of driving, a lot with loads, I now do have noticeable blow-by. It is not horrible by any means but I am still annoyed. Initially, I was not impressed and had a few choice words, every time I looked at the slobber tube.

On the other hand, blow-by is very common with these engines, even when they run well and have good, equal compression all around (as mine has).

I think what I am trying to say is that it is hard to constantly remind oneself that this is an early 1960' engine design that does not manage to be the same sterile, sealed, "powerplant" that modern diesel technology created.

Multis ooze oil here and there, have blow-by and smoke, thanks to the mechanical fuel injection without fancy electronics to achieve lean burn under all engine load situations.

People have been rebuilding these and managed to seal them tight and they didn't leak...for a while....or not as badly as before.....but I have yet to see one without oil streaks.

I am with Davidb56 in the sense that obsessing too much over an engine that starts, runs and otherwise has a few of the old time diesel annoyances only causes severe headaches.

I listened to both of your videos and I think I'd re-check valve clearances for peace of mind. If you suspect air compressor, just loosen the belt and let her run to hear if the sound changes. Otherwise....run it!
 

Bulldogger

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I don't have a multifuel, nor a heaping helping of experience with diesels, but if it's that new and experiencing blow-by (and not the compressor as was ably pointed out) you might do a compression test. I do have other engine experience, and have seen improperly broken in rebuilds varnish the cylinder walls and lose power if pushed too hard too soon or given the wrong conditions or duration of break-in. Your mention of using zinc additives (perhaps a bit early?) made me think of it. Maybe she needs less fancy stuff in the oil for a little longer, to wear in the rings? I defer to those with more diesel experience, as I could be wrong. Just sharing an idea I hope is received in the spirit it is given.
Bulldogger
 

Ajax MD

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Ah yes I had forgotten about the compressor being an issue. My big concern was just that it suddenly seemed different. With two ton in the bed it cruised about 750-800 at 50. Yesterday it was more around 850-900. I'll try to screw around with it today but I'll probably be at work until after dark so maybe this weekend
Brother, I hear you. When I drive, my "spidey sense" just goes into overdrive and I fret every little sound the truck makes. Given the huge effort you put into rebuilding your engine, you must be especially sensitive to sounds and behaviors.

I hate to say it but perform the test with the air compressor and if that doesn't solve anything, just drive it until/unless it gets worse. The problem (if there is a problem) simply may not be detectable until it reaches a certain point of degredation. Given your attention to detail, you will be able to isolate a problem before it becomes critical. You have a good ear and a good, logical mind.
 

Menaces Nemesis

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I bookmarked the following thread a long time ago to remind myself not to go down the rabbit hole like this poor guy did...
https://www.steelsoldiers.com/threads/piston-rings-worn-out-time-for-a-rebuild.139285/
Second sentence of the OP starts out; "I have some blow-by.... " followed by 42 pages of frustration, lotsa money, countless hours, and the guy still got no joy in the end. Like cattlerepairman said, If you pulled the oil fill cap on a late model car or truck and it blew like that, it'd be cause for concern. But we're dealing with 60 year old technology, with 22:1 compression, which was initially intended to power a farm tractor. Don't give yourself an aneurysm over some blow-by and a bit of ticking. Air and fuel filters pristine? injectors and valves dialed in? turbo seals good? fuel delivery and oil pressure good? fluids all good? That's about all you can do. Take a deep breath, followed by a long exhale, and enjoy your truck.
 
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Oerthedge21

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I know, I know I'm looking a little too far into this. Its just so hard for me not too with the way that I am. If I didn't just blow three months and a lot of money on rebuilding the engine I wouldn't care less. My 800$ Mercedes 300d has enough blowby coming out the slobber tube you'd thing the other end was attached to a smoke machine, but I still beat the living s&$t out of it because it was cheap so I don't care, if I just spent that much time inside that engine I'd be just as concerned. I guess I'm probably just overreacting some. I'll try the compressor thing, and maybe a compression test again if I get around to it. In the mean time I may list it up on Craigslist anyway, just to see if there's any interest. Still love the thing buuuut it's not the most practical truck right now and I've been having my eyes on buying a rollback flatbed or building a Mercedes diesel and swapping it into something, or even maybe buying an old multifuel 5 ton since I really like the looks of those things, and bigger is always better. I guess we'll see what happens. I'll try the compressor belt thing and update on what happens.
 
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Buckner Missouri
I am not aware of what is considered acceptable blow by on these LDT's. I am currently fighting a fuel pump issue and understand your frustration that's for sure. I would dig around and see if you can find any definite measure that Military may have stashed in a TM? Or Oliver/White may have some form of measure that can be used. I am in the fleet maintenance end of the transportation industry and have 20+ years of hands on experience working for a very large LTL carrier. I can say that I do not hear a concerning knock in your engine. Actually I cant hear a knock at all beyond what sounds to be normal diesel operation. As far as your blow-by concern, is it puddling oil under the truck out of the blow by tube? If you can find a definate measure as far as what is considered allowable. You can call any diesel shop and get a price on what they will charge to measure it. Most shops will use what is called a manometer to measure the blow-by. But need to find specs on it.
 

Oerthedge21

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Northford CT
Yeah it probably was a slight overreaction, as Menaces pointed out, I had read that thread when I rebuilt mine and it got me all worried that I would end up going through the same thing. I drove the truck some more recently and beat on it a little bit, seemed to have cleared the noise up some. Could we'll have been something in the fuel, or the filters. I have a spin in conversion coming for those soon so I'm hoping to have no more issues after that. The knock seems to change every time I drive it, sometimes its louder, sometimes it quiets down, so I'm not sure but I'm gonna stop worrying about it, if it all falls apart I know someone who wants to buy it lol. Until then I'll just get every bit of fun I can outta the thing and go from there. Though I'd like to keep it around for when I put up a house in a few years but we'll see
 

skinnyR1

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Burlington CT
I'll agree with what everyone else is saying. These are tractors from the 50's that are forced to go highway speeds with a lot of weight. They see get to 30k miles and the engines are loose or blown.

I'm no different then you but have learned through other people throwing money at these things.

I bought mine with fresh head gaskets. The PO bought it from surplus with blown head gaskets. I drove it around for a couple hundred miles chasing problem after problem. All small and minor that I could have probably ignored. But it was always puking from the breather. I tested everything to try and source the problem, short of pulling the heads. I eventually concluded it was probably a cracked head letting water in the oil.

It was also puking gear oil out a worn input shaft on the trans. I was tire of messing with it.

I spent enough time tracking down issues that I had a new motor AND rebuilt trans put in. NOW the truck get in and go whenever I want. I don't have a new leak, tick, whistle or groan every time I drive it. But I paid for that peace of mind. And I treat it well and know its history so it will probably outlast me.

So unless you are willing to swap in new stuff, I would look the other way and keep you money in your pocket. If it blows up, it blows up.
 

Oerthedge21

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Northford CT
Thats what I'm gonna do from now on. Its just hard getting adjusted to how sloppy these trucks are at first. I don't mind a leak or a small noise here and there, my Benz 300D actually leaks more oil than the truck does, it's just as I said I couldn't help but be concerned after all that money and effort into that engine for it to make a weird noise and do weird things again. But **** it, like I was told to do, I'm just gonna run it till it won't run no more, and then put it in the front yard for display until I fix it again.
 
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One thing many people overlook with blow-by issues is the turbo. One thing you can do is remove the pressure intake hose and see if that helps eliminate blow-by. I have seen failed bushings in turbos create high crank case pressures.
As far as people telling you it is an antiquated design and inferior engine. It is not. This engine when designed was far ahead of its years in regard to diesel tech. I deal with late model on road engines of almost every make and model daily. Cummins ISB, ISC, ISX, 60 series Detroit's and the newer Mercedes versions, PACCAR engines and Volvo VD13 engines. None of them run a 22:1 compression they are all around the 17:1 ratio. They also have many of their own design faults from soft cams, piston to liner clearance issues and an myriad of other problems. They are all also governed in the same RPM range as the LDT and LD engine. The only issue I find a fault with on these LDT and LD engines is the fuel delivery system. But I am sure a lot of the issues I have to complain about are due to shotty injection pump rebuilding. As for the piston designs every manufacturer has a dish piston design or utilize what is called a fuel ignition cup on the piston. Gear housing and front cover along with everything being gear driven is also standard on today's diesels. The multi head design has been used on several successful engine designs and is still in use to this day as well.
The LD engines are absolute tanks that more often than not have sustained years of neglect and absolute abuse from multiple different owners in its lifetime. They have cobbled these engines together with often junkyard or hand me down seven time worn out parts. And they still run effective enough to fail so the same people can complain about reliability??? Anyways I would work it pretty good and see what happens. Sometimes it takes a while for everything to seat. Also if you think its a fuel delivery issue this can make knocking sounds. But there is a way to check for issues of concern with maybe an injector? And that is fairly simple. Get it up to operating temp and using an infrared non contact thermometer. Measure each cylinder temp at the outlet port on the exhaust manifold. There should be very little if any difference between cylinder exhaust temps at manifold. A dead or dying injector can make a lot of noise. I am like you though I second guess everything because there is always what if. Hope all goes well.
 

Oerthedge21

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Northford CT
It depends, in terms of design and efficiency combined with their ability to burn a wide range of fuels it's an outstanding design. They do have their faults though, as you said the fuel system and just a plague of less sophisticated metals and materials that made for an engine more prone to failure, there's a reason they were phased out by Cat and then Cummins. However in all other regards they are very impressive and I've seen some take unheard of abuse before, including a thread where the owner snapped the crank in several places and the engine was still able to run
 
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