Recovery of 817 dumper from Sparta Wisc.

[fasttruck]

If you find engine oil in the water the oil cooler may be leaking. The oil goes into the water because the oil presssure uis higher than the water pressure. Oil enterin g through the cooler will cause eventual discharge of fluid from the radiator overflow.

 

[sandcobra164]

I've never seen fuel in the coolant on a 250 Cummins, I'm not quite sure how it wind up in there in the first place. I know if you don't allow about an inch or so below the bottom of the surge tank filler neck (past where the cap seats), it will spew coolant when you get it warm. If you see a slight "film" in the coolant, that's not always an indication of the problem. I've know operators that are true genius's in my short 10 years and counting. Somebody may have poured some oil in the coolant tank at some point in the trucks life!!! I'd check the level, pressure check the cap and go from there.

 

[grunex125]

I had a chance to talk today with a 35 year veteran mechanic who works primarily on Cummins Engines. He explained to me that yes indeed the fuel can get into the coolant, and pressurize the expansion tank, and that the only way that this can happen is for the copper rings around the the injectors that seal between the body of the injectors and the cylinder heads become corroded from lack of proper anti freeze PH., in doing so they develop a pin hole allowing the fuel to escape back up into the expansion tank. This is why I do not have coolant down in the engine oil and crankcase, and also why all the white smoke. I guess problem identified........now time to get the parts around and start fixing. I'll post some pics here for you guys as I go as soon as I get some time to fix'er.

 

[Floridianson]

I always double clutch all big trucks.Glad to here you finallly got it.817s are awesoime trucks,I use mine alot.

The TM that came with the IH wrecker said to double clutch the tranfer case.

 

[grunex125]

Yesterday I started working on the truck, first thing first.......I drained the coolant and let set for a while in some plastic jugs, after the coolant settled over night I came back today to find that in the seven or so gallons of coolant/fuel mixture, I had at least one and half gallons of diesel in the coolant jugs. The first jug had some nasty stuff floating in the top of the container, and the second which was only partly full had the about 2.5 inches of fuel on top of the antifreeze.
I got to work removing the heads as I wanted to know for sure what condition the cylinders were as well as the condition of head gaskets, valves, and heads/block. Aside from the fact that this engine is not exactly new I would say the heads looked decent, the block looked decent, as well as the head gasket. Tomorrow I will take the heads to the guy I spoke of earlier and we will take a better look at those injectors. I'm relieved to know that there is no scoring in the cylinder and even more relieved to see when I drained the oil that there is no coolant in the crankcase either.

 

[dburt]

Lets hope it is just the injector copper seals that are bad. That sounds like the most logical explanation. While you have the heads off, are you going to have the valves and guides looked at as well? I would imagine that they are good to go, but it sounds like your mechanic is well versed in Cummins and will know what to look for.

The cold weather and old lube in the transmission along with any moisture from condensation will cause balky transmission shifting as well. So the advice that has been given to change all fluids and filters is advice well taken by all of us! I have had old tractors and even old trucks have so much moisture from condensation build up in the transmissions and rear ends that in below freezing weather the water freezes and prevents any movement.

Maby some of the white smoke is caused by a partially plugged fuel filter, and/or the slime that builds up in the tanks over time from just sitting around.

 

[grunex125]

Agreed, I'm planning on draining the tanks and installing a new fuel filter as well. would you guys recommend physically removing the tank and turning it upside down and etc in order to flush or would just pulling the plug and draining/flushing that way work?

One of the things that I did yesterday was to drain the oil in the transmission, and even sitting inside a warm shop with new oil and shifting the transmission several times seemed to make a big difference in how it glided through the gears, even without the engine running. Next will be the hydraulic pump, differentials, and any other gearbox that I can find that is in need of oil. also several of the covers seemed to have loose covers due to shrinking of the gaskets underneath. (most were cork gaskets instead of paper.)
I will indeed have the valves and guides looked at as well in addition to have the spring tensions tested.
I read somewhere here that some of you guy's are using regular water and soap to scrub out the water galleries/radiator. Does that work well?

 

[RodUSMC1962]

Great story!When we bought our first duece it looked like a freight train going down the road.No super charger and had not been driven in a bit, we had to back off in the chase vehicle so we could breath!

 

[grunex125]

Great story!When we bought our first duece it looked like a freight train going down the road.No super charger and had not been driven in a bit, we had to back off in the chase vehicle so we could breath!

LOL.........I hear ya there........I think that JP-8 has a distinct smell all to it's own as compared to regular #2 diesel. the car still smells a bit like it. But I'm not complaining I'm enjoying the heck out of this venture so far even with the recent discovery of the need for some repairs.

 

[grunex125]

Today I took the heads to Dave K and he took a look at the heads that I brought him. He seemed to think that the heads were ok and didn't need to be resurfaced, he could tell by the way the markings were on the mating surface that the head gasket was not blown and he proceeded to pull the injectors.
What he found inside was not really all that surprising since we knew there was water in the fuel, but bottom line two out of the six copper linings that were inside the injector holes needed to be replaced.


here is a picture of one copper lining that needed to be replaced, I'm sorry it does not do justice to what I clearly saw, but basicly what happened is that at some time in the past these coppers managed to freeze and distort around the injectors, in doing so it caused the coolant leak and pressurization of the expansion tank. Dave is going to replace these coppers with a special tool that he has and I will send out the injectors to a place called advance diesel in Adams MN. AS for the cost of the injector rebuilds, they were estimated at around 70 each for rebuilding.

I just got off the horn with the guys at Napa and they were not sure as to whether or not the head gasket sets were for one head or for all three on this engine, but preliminary cost estimate on this gasket set was $72 as qouted for me. but that price may climb to around 225 if I need to buy three sets. I'lllet you guys know more later as I find out more.

 

[Danger Ranger]

Good thing you found the problem, I was gonna tell you to check the sparkplugs...hehe.

First thing on your list is to get us pictures of it in use...after its fixed of course.

 

[grunex125]

Here are some more pictures as repairs progress. the first picture is what I found in the coolant, roughly about a gallon and a half of fuel in the antifreeze.

The second picture is of the injector tubes, as you can see one of the tubes was in need of serious destruction to get it out of the head. Dave pulled all the tubes out and replaced them just to be sure nothing else was leaking.

The third picture is some of the valve guides that he found that needed replacing.
they had been knurled already.

The fourth picture is one of the valves, this is the worst one but about half of the valves were not seating correctly and this one had been ground lopsided, probably due to a bent valve stem. My machining background tells me that the stem may have been out of concentric by only a few thousandths, but distance from the collet times dia. can really throw a bad chamfer. On this same note all the valve seats were taken out and replaced.

And lastly the operating room! gotta love that radiant heat when it drops below zero outside. In the back ground is an Oliver 1950 diesel with a 4v53 getting stripped down for an overhaul, and the Red tractor is a 1456 in for repairs.

 

[grunex125]

well we got the truck back together last week, and was thrilled to see that the truck fired right up again. It ran for about 30 seconds and then started to surge in RPM's. It ran up to about 2000 r's and settled in there for a bit and then gradually started idling down until it settled in at 600 r's. no loping but my omnipresent white smoke is still with me to some extent. Not like it was before, but still killing snow skeeters. I let it run for a while and charge the batteries a bit and then shut it off. tried cranking again and sure as heck it fired right up again no problems.

I'd like to address the issue with the white smoke though. I've done several searches here on the issue and it seems the consensus is if it smokes just live with it. However I tend to want o be a perfectionist and so we'll try to get to the bottom of it.

- what we know........... we have adjusted the injectors to preliminary setting of 58 in lbs for first start up, after seeing a marked improvement, we took it for a test drive. seemed to have decent power again, maybe not quite tweeked the way it should have been, but I was more worried about putting too little fuel into the system on initial startup, making it hard to start.
Anyway we get back from the test drive, and I asked my brother how much smoke, what color, etc etc. he says "black on acceleration, white with little or no load" so I set up again and give the injectors 7"lbs more. "black smoke gone, still plenty of white smoke" In my notes I noted a distinct drop in HP. So, anyway we are still interested in getting rid of the white smoke. Engine Temp is running 150 or so on all runs so cold engine isn't the cause. So we set the injectors back at 58" lbs. power returns! still some black smoke but not like it was when we brought it home from Sparta. fuel filter is changed, tanks have been drained and new #2 fuel (actually it is blended) has been added. I check all the old fuel hoses for leaks as the searches here have suggested, we still do not have new hoses on yet, but none appear to be leaking either, also there is no need to prime the engine before starting. It fires right off with just a little preheat and about four revolutions with the starter. If I prime the system it fires within the same no. of revs.

-Now for my questions....... 1) I have read here that some have been experimenting with adjustment of the fuel supply pump, has anyone actually had any success with slight advancement of the pump or retarding the pump a bit? 2)will fuel supply pressure to the heads affect how much fuel is actually entering the engine or can it be forced into the cylinder on say for example the exhaust stroke, if the pump pressure is set too high?
3) I've read here a bit about the NHC-250 having pistons that had three rings instead of the newer pistons with four, I'm assuming one was an extra compression ring or something of that nature. does that make a difference? My compression in the cylinders is up to par or so I'm told so I'm thinking compression is not at fault here. Just wondering if that extra ring could be some of the difference?

I will get more pictures up soon to show you guys/gals what kind of smoke we are getting.
as well as some more pics from the repairs.

 

[sierra117]

This might come off as dumb but you sure the smoking is not because of the colder weather.

 

[grunex125]

Sierra117: that could very well be, I guess I would be interested in hearing from the membership here if that is a common occurance or not. My temp today was about 30 degrees or so. I've never had a diesel smoke white after it warmed up but that don't mean it isn't possible. My mechanic friend says no.....but then again these are 40 year old trucks and anything can happen over time.

 

[grunex125]

Here is a picture for you guys to see what I am talking about. When this picture was taken it was about 30 degrees out, the truck had it's fuel filter changed and all recent work on the truck completed. I got the truck started and let it run for about an hr. the temp came up to about 160 degrees, and the picture was snapped, I have a few videos of the truck running as well, but i do not know how to post videos here as I cannot save them to the computer for some reason. They always come up as a still photo..........dunno what I'm doing wrong. anyway, blowby is nill.......engine temps are normal, oil pressure is good at 60lbs. starts good in the winter time, and very little issues to speak of otherwise. oh yeah I should mention that the snap shot was taken on idle, but it does not change much all the way up through the RPM range. Smokes still the same just larger amounts.

 

[70deuce]

At 22 degrees my M818 has just a tint of brown/black smoke cominmg out. Nio white smoke at all.

 

[70deuce]

Nice spelling, Huh?

 

[axlr8]

just a thought here....was there any condensation in the cleaned tank? how long were the lines not full of diesel? and did some water get in the pipe? Im leaning towards fuel setting, or water.

 

[tie6044]

I always thought white smoke from a diesel was bad, then again, I'm no mechanic and don't claim to be.