Anybody have an idea on how many hours a set of injectors is good for in a 5.9 cummins? I know that is kind of a loaded question but just looking for a rule of thumb to go by. A friend of mine had the head off his D5C awhile back and thought he would have the injectors tested while he was waiting on some parts. They all tested bad on the spray test even though the dozer seemed to run fine. He ordered new ones and says he can't believe the difference in power. It just got me wondering.
Mechanical or Electronic? Differences in fuel filtration @ micro level.
I should have added that. Both are in a mid 90's model dozer and are mechanical injectors. His dozer had around 6,5000 hrs but engine was replaced at some point in it's life. Mine has about 4,100 hours and everything appears to be stock. Not sure on filtration. I run the fuel filters Case calls for and change them every 250-300 hours. Who know what previous owners did.
Mechanical nozzles wear internally, springs, lapped parts as well tips foul and orifice in the tips erode. Electronic units develop coil degradation leading to declining dwell time or increased resistance where the dwell cannot be maintained for a performance level, can also see delivery tip degradation where the spray pattern is not sufficient to efficiently combust.
Maybe I should pull them next time we have a down week and have them tested. I hate to do that and run into a bunch of unexpected problems if not needed though. I've been told they can be hard to pull and have a seal washer under them that can be hard to replace. Dozer runs good. It never black smokes and is starting to blow a little whitish blue smoke but isn't burning any oil. I really suspected the turbo oil seal but the deal with injectors got me thinking.
All you can do, is have them tested.. no REAL written intervals for replacement.. All depends on filtration.. fuel quality.. pump timing & engine "soundness"..
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while running a case tractor dealer shop many moons ago, found 8.3 liters self distructing because of bad injectors at around 5000 hours, we recommended replacement at about 4000 hours. most cases engine problems were not noticed by the owner. some tractors went way past that with no trouble. the ones that failed burnt a hole down the side of the piston, with much blowby. price of injectors beats the price of an overhaul big time. would put the 5.9 in about the same time frame, but that is just my .02$ we used factory remaned injectors at first but several leaked fuel externally, new injectors worked right the first time. but remaned quality changes from time to time.
Probably time to at least get them tested then. Might be best just to buy a new set and change them out and have old ones tested just for the fun of it. I ran the valves over the winter and the gaps checked good. I've been wanting to do a blowby test with a manometer but just haven't made the time. Definitely want to be proactive and not blow a motor over something that will need to be done anyway.
Well I just found out for the last few days I've been searching for these injectors with an old part #. New part # brought up some more options. Brand new aftermarket injectors are 1/2 price of Case branded. What do y'all think? Buy from dealer or go with aftermarket?
Whats the P#> I may be able to steer you in the right direction.
Old part # J919323, New part #J919343. The ones I'm looking at have a part #C1703-3412T. I've found them several places but a quick Ebay search will bring them up. Thanks for the help.
have seen a couple of times in my life injectors test good on the stand and go to sticking or erratic operation in a hot engine. as for case or other brand injectors for a do it your self check into warranty, half price is tempting.
I just saw the post of the P#, so haven't checked prices yet.. BUT.. incase you didn't know.. Sub. a 3 for the J for Cummins #..
I just found the tips for 20.00 on ebay.. new bulk. BUT it takes a special tool to replace them.. I have that tool.. I don't have any cores to build.. BUT.. if you could be down & send them to me?? your call..
That may be worth doing. Let me see how things go tomorrow, found out today I might have a fairly big job to start on Monday. I talked to a buddy that's got a diesel shop and he says he hasn't had trouble out of aftermarket injectors. Let me see how tomorrow goes.
I went ahead and ordered a set of injectors ( thinking the less down time the better) because about 3 weeks worth of work came up and I got a contract to buy some land that connects to me that will need about 100 or so hours of dozer work ASAP. Well as luck would have it we blew a hose Friday, got 1.5" of rain Saturday, and operator can't work Monday. To top it off injectors aren't scheduled to show up this Friday. I guess they bringing them on horse back or something. Anyway thanks for the help and I will update on wether or not any difference was noticed.
I finally got time to tackle the injectors and ran into an issue I hope someone can help with. All 5 of the injectors I have tried to pull so far have been stuck to the hold down nut. I was able to get 3 of them free by holding the injector head with a 15mm wrench and turning the hold down nut with an offset box end wrench. Once I got the nut off the injectors actually came out easier than I thought they would. My question is how can I get the other 2 loose? I'm afraid if I just turn the hold down nut and let the injector spin it will break the locating ball off and if I'm not really careful the pieces could fall into the engine when I pull the injector. I've got them soaking in Kroil overnight but really don't think it's going to help. The injector I haven't tried yet is the hardest to get too so I'm saving it for last. On the 3 I got out once I got the hold down nut loose from the injector the nut spun out pretty easy. Please let me know what y'all think on this.
Make sure you dig out the square-cut o-ring around the hold down nut. It may not look like there is one, but trust me there is. With that out of the way, you get penetrating oil down between the nut and injector body. And yes, you don't want to wipe out the locating ball groove. Also, be careful. I had one do the exact same thing. While trying to "force" the nut loose, the open end of the 15mm Craftsman Professional wrench broke and shot part of the ear all the way across the shop!
I looked and didn't see the oring but will try to dig it out with a pick tomorrow. I hear you on the wrench breaking the 15mm slipped on me today and got me above the eye. Thinking I can take a drift punch up there in the morning and give the nut a few good blows to loosen up the crud. Only other thing I can think of is to screw the lug nut I'm using to pull the injectors on pretty tight and hold it instead of the injector body. Kinda worried this might beak the injector head off though. I sure hope the one I haven't tried yet goes smooth.
Are you using a slide hammer to "pull" the injectors or just trying to pry them out?? Gotta use a slide hammer..
To get injectors out I'm using a piece of 1" pipe cut to about 1" long placed over the injector, then put a washer on top of that and screw a metric lug nut on the top of injector where fuel line goes which presses on the washer and pipe and pulls the injector with ease. The hold down nut has to be removed to do this. On the 3 I've changed once I got the nut broke loose from the injector it slid off the top of in injector fairly easy. I'm having trouble with the hold down nut being stuck to the injector and making the injector just want to spin in the hole. 2 of them are really froze to the nut pretty good. I'm going to try and just be patient with them today and keep using kroil and tapping on them until they break loose.
Just finished up the the injector swap. Everything went fairly smooth except for the 2 stuck ones, #4 & #6. I was able to finally get the hold down nut freed up from the injectors with Kroil, heat, tapping with hammer, and working the nut back in forth while holding the injector. There has to be a tool out there the fits the injector to keep it from spinning. #3 was the hardest to get to and surprisingly came out the easiest. Dozer sounds the same and it is too wet to see if they made a difference or not (we had about 10" of rain this week). Hopefully none of them will leak. Thanks for help. Oh yea none of the injectors had the oring to keep debris out. I did take the time to put the oring on this go round. By the looks of things and the part #'s on old injectors I'm guessing they were the originals.
Find and get the tool to clean the nozzle bores in the head, if not the new ones may not seat properly, also replace the seal washer at the bottom of the bore, make certain you get the old ones out. The tool could look similar to a milling bit, a brush type may be available and may function alright. You want these bores clean for seating and torqueing the nozzles into place. Just be cautious as I believe these are tubes set into the heads and can be damaged.
DMiller, I didn't have the bore cleaning tool or a brush to clean out the bores. I did use an inspection mirror and flashlight to look in the bores and they looked really clean. I soaked a shop towle in Kroil and cleaned the bores best I could then blew them out with air. New washers were used and I made sure all the old ones came out, also made sure new ones were same thickness as old washers. I am a little worried they might leak but there is only so much you can do. I wish I had known about the brush deal earlier, everything I read said blow out with air.
I cut an old injector line, about 8".. cut a 1-2" slot in it w/ a hacksaw.. put in a piece of scotchbrite, put the rod & sb in a drill & go to work on the holes/tubes.. & then just spin the motor to get the crap out.. That's one of the handiest tools in the arsenal.. Just a little tip from your Uncle Larry.. lol
This is how I pulled the injectors once the hold down nut was removed and a pic of one of the old injectors. Thinking about having them tested just to see if there was a problem or not.
The tip looks "alittle" fuzzy on the end but not bad.. not bad at all + its clean all the way to the body.. Just for kicks, I would ADVANCE the timing a * or 2.. just to see if you could get a cleaner burn.. Honestly tho, it "looks" good.. are you idling it afew minutes before shutdown?? To advance the timing, bump the engine over & see which direction the fan spins.. Go to the pump & mark the flange to the block.. move the pump about a "dimes width" [not much] OPPOSITE the direction of the fan spin & lock it back down.. & see what that gets ya..
I just did a set today.. the pressures were ALL OVER the place.. they popped "decent" but not factory .. + they were coked, BAD.. They varied from 3100-4500psi.. spec is 3550-3850.. way out.. over & under..
Thanks pumpguy. I might try to advance it. All the injectors looked about the same. We always drive it quite a ways to the barn after using it and let it idle for a bit, mainly to let the turbo cool. I'm still a little confused on the No black smoke under heavy load and the puff of white smoke on start up or after idling for a minute or so. It was burning about 2qt every 125 hrs, so I put lucas in at the last oil change and it quit using oil. I suspect the smoke is coming from the turbo oil seal. Thanks for the help evryone gave me on this.
That engine should not put out any black smoke at all. It was common for them to put out the white smoke and then light blue at start up cold. I used to figure that from the valve guides until the head warmed up. The oil burn would be considered acceptable by Cummins standards. If you have a manometer or a gauge calibrated in inches of water you could check crankcase pressure. That might tell you if you have some cylinder and piston ring wear. I used to figure injector life on mechanical engines at around 5,000 hours or so. I haven't seen many of the common rail engines go much more than 3,000 without some kind of problems.
John C., after what you say and talking to a friend of mine that has worked on cummins engines for 20yrs plus pumpguy saying injector looked good, I'm leaning towards no black smoke is fine. I always hate to ask the diesel mechanic I know too much. I guess he works on this stuff all the time and hates to hear about suspected problems on his off time. I did the generic blowby test of warming the engine up then placing an empty beer can on the oil fill spout and while I did have to loosly hold the can in place by no means was it trying to blow it off. I plan on making up a manometer to check it out for real but until then I'm just going to say this engine is good to go. I have two common rail cummins pickups and am dreading injector problems on them. Seems like $3,000 + is the norm. Had to replace the variable vane turbo @ 85k on one of them. I guess more power doesn't come cheap.
The V V turbos are a NITEMARE from a rebuilders standpoint.. I've done 2 & WONT do anymore.. The injectors on those CR systems aren't bad.. I guess I'm used to the cost by now.. but its the LABOR that's the killer.. the labor can be double the cost of the injectors.. I don't work on them.. Takes 8hrs + ALOT of hard work.. I have a hard time looking a customer in the eye & telling him he owes me 3600.00 for a "skip".. You can watch the blood draining from his face.. Give me an old Ford or Case tractor ANY DAY..
The VV turbo that went out was on my 07 Dodge C&C. I don't drive it allot so it just turned over 98k yesterday. The turbo was going out for about 18 months. When ever it would give trouble I could just kill the truck let it cool a bit and then everything would be fine. My buddy that has the shop would ask if I was ready to replace it every time I stopped in, I just always said not for $1,800. Well I was hauling a tractor when it finally gave up. It pulled perfectly fine I stop to get fuel and go to leave and blah no power and killing it wouldn't work. Unload tractor and trailer get that stuff back home (only 10 miles) get back in the truck and drove it to the shop with full power. Crazy how those things get gummed up and stick. They put a new Jasper turbo in it. He said he has done all kinds of crazy mods for customers wanting to get away from the VV turbo. Several years ago my neighbor had 1 bad CR injector bad and 2 that were suspect he replaced 3 instead of all 6 and 6 or8 months later the motor blew up. Burned a piston on one of the cylinders with old injector in it.
THATS what I'm talkin about JS.. a customer has a "skip" & wants JUST THAT injector replaced on account of the cost.. THEN you have to go thru the whole song & dance about how it costs TWICE the amount of labor to do the next 3 or 7 when THEY go out.. in just a couple of months.. {they ALL ran the same fuel thru them & had the SAME heat build up} I got tired of it & just plain wont do any more..
I know the newer engines are a great deal cleaner, they are better controlled and easier to deal with as to electronic diagnosis but I as a old timer will never be sold on the financial viability and liability of these. Simple hard mechanical systems that last or lasted forever even as they aged and got weak, can hardly beat them. I really do not expect to see 40+ year old electronic Cats still working.
I think your right DMiller. The days of diesels lasting along time and being fairly inexpensive to operate are probably over. Every time I hear someone say "It's only got 125,000 miles on it it's just getting broken in". All I can think is almost time to drop 6 grand on injectors and a new turbo, maybe the injection pump will last if too much bio fuel wasn't ran through it. Oh well I guess it's progress. The computer problems are getting easier for a $100 an hour tech to troubleshoot though.
Troubleshooting yes but repair costs steady rising parts wise! Then those seemingly inconsequential detractors, oil, moisture, age of connector contamination. In my past life in a power station we came across a wild problem, electronics growing connective hairs(tin whiskers) and shorting themselves out internally, another issue to consider.