In my last post I ended up buying a ford LTL9000 with a Cummins ntc350 big cam. Now the troubles have arrived. I am desperate for an expert on these engines. The truck has a lot of blue smoke on start up and when warm. It also feels like it has a slight mis. The biggest problem is it will blow oil out of the dipstick tube. I am leaning towards bad rings, injector, valve guides.... hoping for injector. I checked the draft tube and it is fine. If I take the oil fill cap off it relieves all the pressure and it stops puking oil. It does make a funny sound almost as if there is compression blowing through that cylinder bank and out the oil fill. It might just be the shape of the hole causing it to sound this way. Another odd thing is there is no fuel, coolant, oil mixing anywhere in the motor. I feel like if it had bad rings or a crack somewhere I would find fluids mixed. I am not used to working on mechanical diesel injection and was wondering if someone could point me in the right direction for testing the injectors or if someone has had this type of problem before and could school me. Also where can I find the valve/injector adjustment procedure or a service manual. I don't want to pay cummins $100 for the book when I will still be asking you guys for advice. And I am not taking it apart until I have the specs to put it back together properly. Thanks in advance
Sounds like you scalded a piston ....on the down stroke of the piston is making compression in the crankcase ... when the motor is cold start it up and feel the temp of the exhaust manifold at each cylinder to determine which one it is...it will be cooler than the others. Good luck..
Well, it looks like you are right. The number 1 cyl is ice cold. Is it possible that this is an injector not firing? Or because of all the blue smoke its unburnt fuel from that cyl? Anyway to fix this besides an in-frame?
tbone,,,, yes,, could be bad injector, or out of adjustment ...... pull the valve cover and have a look,, pay close attention to the cam followers too when you have the valve cover off
Do you know what the specs are for the injector setting and valve lash? That way when I pop the box I can check it out.
I believe the injectors are set at zero lash.... takes a special tool to do that. I am a little concerned about the blow by tho tbone... thats not good. Back to the zero lash if its not correct you will take your camshaft out.... so take a flashlight and look down, there.
There were two methods on the internet that help get around the tool. I think one uses a dial indicator and the other is tightening the screw to 5-6 in/lbs... could the blowby be a result of the bad injector? One thing I can't get past is there is no mixing of fluids....no fuel in the oil or water in the oil.... I don't think I have ever had to tear a motor down where all the fluids were still where they belonged. Someone at the autoparts store said if it was stuck rings there is something people put in 2 stroke boat motors to free them up. Was thinking this may be a way to go just don't know what its called and if that isn't the problem what issue am I going to have from it. What am I missing????? It has to be simple right?
Simple, broke piston .
Well, im afraid its not gonna be simple.... the blowby has me worried.... the zero lash tool runs 70 bucks... if its not right, a new camshaft is 1800. Keep us posted.
You can use the 6inlb method on top stop injectors, don't know what year this is but it should be top stop. Dial wrench is the way to go. It sounds like you have a cylinder down on compression, probably bad ring/ liner. I think the tool Grandpa is talking about is a screwdriver type, they work well. If you can feel and here that puff sound out of the blowby tube, it's got to be a bad cylinder. There are the compressor which can cause some blowby, and never forget turbo seals, but they won't cause heavy blowby or that puffing at idle.Good luck T-bone
Never seen a bad Injector cause blowby..Had a Ford with two galled ones.Just missed no blow by.Put about two gallons of automatic transmission fluid.If this engine has lots of miles in frame kits not to pricey.If you want to patch it find bad cyl.replace it.I do think you have a galled piston and sleeve ar a cracked piston.
There's no doubt in my mind you have a bad piston. You say #1 is running cold, I would drop the oil pan and look closely at the liner from the bottom with the piston all the way up. You will see scarring on the cylinder wall. There's a good chance you have a bad injector that caused this problem. The good news is, these are about the cheapest engines on the planet to overhaul. You can buy the whole overhaul kit cheaper than you can buy a couple injectors for a new engine. Also, don't figure on stopping the cold smoke. I've never seen a BC Cummins that didn't smoke cold. With all 6 firing, smoke will clear up when warmed up. Good luck, Steve
Forgot 1 more thing. Save yourself a lot of headaches, and don't try to order parts by block tag numbers. Get the head off, and get numbers directly from piston and sleeve. Who knows who much machine work may have been done in there.
I appreciate all the advice. It is a 1987 with top stop injectors. Odometer says 328,000 but its probably 1,328,000. I guess I am coming to terms with it. The number 1 cylinder is trashed. My fingers were crossed for anything else. Ran it with the valve cover and brake off, there is smoke coming up from the bottom of the cylinder. I am not looking forward to doing it. I stopped by a local shop and they happened to have an ntc350 Big Cam with brake. I was thinking about just swapping motors depending on what they want for it. It looks like the rebuild kit is about 1000 and all new injectors for 300. I would like to buy them from someplace reputable. Anybody have any suggestions? I have never relined a diesel. I subscribed to cummins quickserve and they seem to think its an N14, so it wasn't really worth 100. Doesn't even give the correct valve adjustment procedure. Still, it doesn't seem like this will be the most difficult job. But, I don't have a sleeve puller/installer. Do I really need it? And, I've seen things about a wear ring in the top of the cylinder???
T-bone, you need to have a liner puller or fab one, and a 3/4 torque wrench, I'd try Ebay for an old NT manual.The liners have shims under them, until you get it apart you really won't know what you have. You can do it yourself if you want to put in the time. Try Apex Industries Tools they have alot of aftermarket engine tools, they are online. I'd suggest a good aftermarket kit I like PAI for Cummins real good quality stuff. Get it apart before you buy anything, you might get in there and find the block to be junk. Good Luck
ha ha ...good answer put another motor in it ...thats the cure all ...what are you a french teacher by day ??
The problem nowdays with the 855's is finding one better than what you got, alot of these have had serious block work done. Don't buy anything you can't hear run to operating temp, and check for mixing fluids, and combustion gas in the cooling system, unless they offer to pay labor to pull it again.
French Teacher? Not quite sure I understand the reference. While swapping motors is no panacea, it is a solution. Like any other business decision it comes down to time and money. I have jobs for the truck sold starting on the 25th. I feel like it would be faster to swap motors than do the rebuild and if the motor lasts through the summer thats fine as long as the truck is making money. I would prefer if last indefinitely but it sounds like that is not a reality. I will keep you guys posted on how it works out and please keep the advice coming.
If it where mine I'd rebuild it ...then you know what you have ..These Motors are very inexpensive to rebuild ..just my thought why buy something else that may have issues all by its self ..
The 14Lt Big cams are fairly simple to work on, the injectors are best set with an inch pound torque wrench,this is done by the outer base circle method, I can post you the correct method if you require it, you set the injector first then the valve lash to get the best results, the 5-6 inch pound setting is used on engines with stepped timing control, even on TS (top stop) motors I get better results with the torque set method, you can pull the cylinder liners without all the pro kit, all you need is a bit of steel, a bottle jack plus a will to get things done, plus getting the block drained of water helps no end, a good tip is to place the B/End bearings onto the crank pin with a plastic cable tie (zip tie) this keeps crap out and saves damage to the pin. tctractors
I guess a little luck came my way today. I caught up with my neighbor who is a fleet mechanic with a construction company. Said he has Saturday off and thinks he can have it fixed by noon. He said just do it all and be done with it.... As far as valve adjustment goes I read on Pittsburgh Diesel's website that the way to do this motor is by the inner base circle at 6in/lbs. It falls in the 10 or so year period that Cummins used the IBC method....
tbone, I do about 15-20 of these motors every year and have tried all ways of doing the over-head set, most of the engines I do are Load-bank tested as soon as they are done, both the 2" and 2-1/2" Cam 855 engines give a better performance when they are set via the torque set method, it is also the easier method to use, anyhow its just my prefered method we all do things our own way. I am glad things have worked out luck wise for you finding a local willing to give you a hand, lets hope your troubles are the easy fix sort. lots of luck tctractos
Tctractors, could you post your method and we will use it. I don't feel entirely comfortable using internet methods on something so delicate. I have ran into so many problems today with parts. I had to have them ordered by 3pm so I had to take the pan off and pull some caps to make sure the bearings were std, I forgot how much it sucks to work in the rain. All this on top of my normal workload. Apparently, the serial number is a 1982 ntc-300 and the cpl is a 1987 ntc-350. Called Cummins and they seem to think that at some point the pump and injectors were done to make it a 350. I went by the cpl number and ordered the parts. I went through so many questions with different parts people down to what the compression ration was.... How the hell am I supposed to know??? Its funny how my problem has gone from getting the labor done to getting the right parts. I am not sure I even ordered the right parts. The weight on the shipment was 319lbs which seemed way high. Tomorrow I am going to drop the injectors off at a local fuel shop just to make sure that a bad injector didn't cause all my problems and pull the heads. It wasn't as bad to work on as I expected everything was just extra greasy and heavy.
This doesnt help your questions, but I can add that for the last 15 years I have owned many dump trucks. About 60% had Big Cam Cummins and the others Cat 3306. I have owned 2-Cat 3406 and 2-Cat 3176. I honestly can stay, I have never had any major problems with any of them, but I really like the Cummins Big Cam. At present I have a 88 KW quad dump with a L10 Cummins, 94 Ford quad Cat 3176, 89 Freightliner dump, tri axle Big Cam Cummins, 84 Ford L900 tandem, Cummins Big Cam, jake brake (it works) original engine, no major overhauls, es State truck, 250,000 miles. I agree with what you are doing, its cheaper to rebuild what you have and you know what you have Good Luck
You said in your first post that you didn't have the manual, and it was $100 from Cummins, I would HIGHLY suggest you spend the money and get one, or check e-bay for a used one, do a search on the web, there are book shops that have them for sale. I never tried one of these, but it is on E-bay right now, quite a bit cheaper than a manual. http://cgi.ebay.com/ebaymotors/Cumm...20708174504QQptZMotorsQ5fManualsQ5fLiterature I thought I would be able to get thru my first overhaul on an 855 back in '91, had a good friend who had done a few who was going to help, of course he wasn't there when the first question came up, so I asked Cummins, and of course they suggested I buy the manual. Best thing I did, as there is a sequence to tearing down, and reassembly. When you get to a question, and ask here, you have to wait a while for the answer, with a manual, you get the answer right away. Also, I have adjusted valves and injectors both ways, the torque method is the best. George
I actually purchased the manual from cummins on their Quickserve site. But, they seem to think it is an N14 Celect motor. I spent 100 on the manual and it is the wrong one. Ironically, I had to put in the serial number from the engine to get the manual. For some reason on the website its an N14, talking to Cummins on the phone by the serial number its a 1983 NTC300, and by the CPL its a 1987 NTC 350.
That is exactly why I said to tear it down and get exact part numbers instead of cpl and serial #'s. The blocks are all interchangable so who knows what might be inside.
Might I say that Cummins engines although I love them, they are fairly technical in their construction, A CAT 3306 motor is a very simple build to compare, the 3306 is the cheapest engine to re-build in the U.K. in the 10-14 Ltr size, the Cummins liners even use a bit of selant under the counter-bore, I would class the Cummins engine as a High Build unit that needs a good study of the hand book to get things correct, even the back case (rear Bell-Housing) on most Cummins motors is not dowled in place requiring DTI setting for correct position, the 14 litre engine with its stepped Woodruf Keys and Cam box shimming is not for the odd job lad??, the more you do the easier things get, like doing the over-head set of the injectors and valves, a great help is making the marks on the A.D. pulley clear, I use a Tippex pen to make things easy, I also check the index of these marks with No 1 or 6 on TDC before I get to deep in doing it wrong. tctractors p.s. tbone I will post the Torque set info, but I dont want to step on the toes of your local Mech with my crap, we all do things to our own ways, best of luck.