I have Cat D6H LGP serial #5HF04098. was working fine then all of a sudden started to produce serious black smoke and lost power. Revs would not pick up. We checked turbo, inlet and exhaust for blockages. All fine.Checked injector pump and injectors. All fine. Checked timing. All fine. Removed transmission pump drive and pulled the hydraulic pump out of position to see if they might be loading the engine but no change. I am not sure what to do next. Please help. The rockers are all lifting and push rods are all straight. Indicating cam should be fine. Ran it without the exhaust manifold ANF serious black smoke was coming out of each exhaust port. Any suggestions would be greatly appreciated. Many thanks
Heavy black smoke and low power are indications of over fueling. That can be caused by Inlet air restriction, loss of turbo boost, injector spray pattern being inefficient. I would check the turbo 1st. Look inside the turbo ends and see if either impeller is striking the housing. Look at the edges of the impeller fins to see of they have a roll at the ends. Also check the boost hoses and make sure the clamps are tight and not broken, then check the hoses themselves for cuts or breaks. Look for engine oil inside the boost hose or inside the turbo inlet or outlet housings. It sounds like a classic loss of turbo scenario to me. I have seen an intake manifold gasket get pushed out of place and cause turbo boost loss also.
Does the engine appear to start and idle OK with little or no smoke..? Did you try running it with no air filter elements installed..? Have you dropped the rear bottom guard and been into the torque converter magnetic suction screen looking for debris..?
Thanks for your help. It is not even starting now. Just serious smoke coming out with the starter cranking. Have tried to use quick start but no joy. Injectors are agonising nicely
Ran it without air filters and no change
This. ……..and has there been any recent work performed on the machine?
I bought the dozer recently and have used it for 600 hours . Not sure of the history. The engine has run great since I bought it. I will check the torque converter for debris. Is it possible that it could be loading the engine. When I crank the engine the prop shaft seems to be turning smoothly
The dozer has done 8300hours
could be a head gasket blown between the cyls. that will make it smoke too
I wouldn't expect the shaft between the torque converter and the transmission to turn at cranking speed, only start to spin once the engine had fired up.
Does it have a positive air shutoff that is partially tripped?
I cranked the engine with the starter motor with the exhaust manifold off. Black smoke is coming out of all the ports equally. All dry so I think rings are ok. I don't have a compression tester. I don't think that it has a air shut off. I have a video which I am not able to upload on this platform but I can send via whatsapp .
What is the engine model?
3306 DI with a new scroll injector pump. I fitted a reconditioned pump. No change. Behaved the same. I removed the injectors and ran them externally connected to the pump via Hp pipes. The injectors were atomising nicely
At the risk of repeating myself I still think there is a distinct possibility that your issue is South of the engine flywheel.......at the very least IMHO you should eliminate that possibility before proceeding further.
I will check the torque converter for debris in the morning. Thanks for your advice sir
Hi nige sir I hardly need ur assistance Trubleshooting D6k2 crank but not starting
If I'm reading this correct when you said you ran it with exhaust off would I be correct in thinking that means the turbo was off also? If so I'm thinking you would be sure there was nothing that would possibly be restricting air to engine. If that much is correct then I would be looking close at what Nige says about a problem with a failure of something causing a heavy load on the engine. You mention the shaft from the converter turning when cranking the engine. Just for kicks I would try turning that shaft by hand without cranking the engine. I would expect some resistance but I would think it would turn by hand or with a small prybar if you can't get a good grip on it by hand. If it won't turn by hand I would next remove it and see which end the problem is at. Either the converter or transmission. Here's a different view of that screen you need to check cover is marked red:
Make "hardly" read "REALLY do need"
Dgze, Two quick suggestions. First, start a new thread for your question. It makes sure your problem and this guys problems don't get confused or missed in the shuffle. Second, Give the full serial number of you machine. Third, yea I know I said a couple but who's counting, give a short description of the problem like what was the machine doing when problem showed up and any other work that has been done recently. Good luck.
Thank you. I will check screen and report back
Sir I have opened new thread for my question but no response from any one that's why I write there sorry for disturbing . Serial no-CAT00D6K HMXK00267
Good evening.
Good evening. I checked the screen which was clean . I then turned the prop shaft to the transmission by hand. I rechecked the timing. It was spot on. I am now convinced that it is an engine problem. We cranked it again. Plenty black smoke and not starting. I think that it must be lacking compression. Can it go from running fine to not starting and no compression
Hope others can give more information but every engine I ever saw that was not starting due to low compression smoked white and it would burn your eyes, raw diesel. Black smoke would seem to me to be due to starved for air, like maybe a seized turbo or very plugged air filter. Someone didn't stuff a rag in the intake while changing air filter did they? Is there any chance you could upload a short video of this engine while trying to start. Often things can be seen that will give a good idea as to the problem. Or even have some one take still picture during a start attempt may help.
How did you check the timing did you just line up the pins the reason is I had one 180 degrees out and it would start but no power and smoke like crazy you may have to pull valve cover and verify that number 1 is on compression . I know its a long shot but sounds like a timing or air restriction problem to me. If it is smoking evenly out of all ports it should rule out head gasket
Morning. This is not letting me upload a video. The timing we have done by the book. Timing pins in the flywheel and in the injector pump camshaft. Then no. 6 cylinder rocking.
Well, something isn't making any sense. Im not sure we have the correct story...…….or there is pertinent information missing here.
I have always timed them with both rockers rocking on number 1 when you said number 6 rocker rocking was it both rocking because if it is then it is 180 out
TDC #1, both rockers should have valve clearance. The opposite cylinder #6 rockers should be overlapping. Quote: D6H manual, 'The No. 1 piston is at top center on the compression stroke when the bolt can be put in the flywheel through the hole in the flywheel housing, and both rocker arms for the No. 1 piston can be moved by hand (have clearance with the valve stem)'.
#6 its 1 5 3 6 2 4 . Bob
You'll have to upload the video to U-tube (or video host) then post URL link into this thread.
I see you tried it without an air cleaner, and without the exhaust manifold. How about hooking up a line from the intake manifold to a vacuum gauge and seeing what you get when you crank it? or remove the intake hose from the intake manifold and try it that way, being careful that there is nothing nearby to get sucked in. If the exhaust ports are dry, then either Nige is right about it being a drag issue, or it's not getting enough air, or the timing is way off. I'd sure like to hear what it sounds like cranking, a shot of the exhaust would be nice too. Have you checked the blowby tube for excessive oil leaking? How about the engine oil level and condition? Coolant level? is this running ethylene glycol antifreeze or water?
Something has to have been done wrong for this engine not to run. It's basic physics. If you have enough air supplied with the right injection timing and enough compression, its impossible that the engine does not run. So this goes back to the repair of the engine and I'm saying that it was not done correctly. I've never seen a 3306 engine that was timed on #6 cylinder. I also don't recall one of those engines having a pin timing on the flywheel but it's been many years since I've done a rebuild on one.
Well they have a 3/8 bolt that you screw into the flywheel and a pin on the injection pump
3306s Time #1 TDC (#6 is on the exhaust stroke; exhaust rocker arm opening > exhaust valve moving downwards) Flywheel timing hole is located above and inside of starter mounting hole. Cat 5P7307 Engine Turning Tool Group is used with starter removed and 1ea 3/8" NC X 4" long bolt (inserted and tightened) to pin flywheel location @ #1 TDC. Injection Pump: Timed with 6V4186 Timing Pin inserted (with finger pressure pushing inwards while turning the injection pump with a wrench) into the timing port (hole) to lock the injection pump camshaft. Timing Gear retaining bolt torqued to 270+/- 25N.m (199 +/- 18lb. ft) OP's description, ' sudden loss of power and black smokey exhaust' 1) turbo failure or restricted air intake 2) power train failure; sudden no metal shavings in the screens?
I can't recall how it ran but I do know that even with pump timed 180º out a 3306 will start. Been there done that, I'll blame the timing error on Norm as as far as I know he is not on this forum . Now that was a scroll metering system that used the special tool you bolted to the pump drive before installing the pump then after bolts in timing gear were tight you removed tool and installed the pump. And like Delmer says the two most likely things would be too much load on engine or not enough air! I can not think of any way that a compression problem would cause black smoke especially on all cylinders. Black smoke tells me it is trying to burn the fuel but not getting enough air. If the origial poster can not figure out how to post a video he could "Start a Conversation" with me and I'd send him a email address so he could send the file to me and I would upload it.
Does the engine turn by hand as easily as it should? I guess anything is possible (sheared key?) but I think the timing changing suddenly is unlikely. compared to the powertrain locking up, or the engine locking up, or an air hose collapsing.
There isn't a rag sucked into the intake tube, is there? I might be off base here, but if I had taken a turbo off, I would have used rags, bags or latex gloves to cover openings to keep unwanted items from ending up inside. Is it possible one was used and forgotten upon reassembly?
No air hoses, uses pipes and O-rings Does the engine turn by hand as easily as it should? Good question. Injection Timing; slipped? Injection pump uses taper-to-drive gear taper, no key; torqued to 199lb. ft. Not likely to slip if installed and tightened correctly. From the OP's descriptions, he's focusing, changing parts and testing on the wrong engine areas that he's already eliminated. IMO, sudden (loss of power and black smokey exhaust) indicates something broken (turbo is okay?) YES = eliminate. Engine air induction system? NO air cleaner restriction = eliminate. Fuel injection system? Injection Timing is okay? YES per OP's reply timed with #6 rockers, rocking = eliminate. Per OP's description, 'equal black smoke from each exhaust port'; indicates adequate compression to ignite the injected diesel fuel = eliminate low compression. Low compression would be white-gray-blue-ish smoke. Something putting a drag on the engine? OP stated, 'engine would run, now won't even start'; indicates seizing part(s), gears, bushings, bearings, driven shafts, pump(s) OR main-rod bearings seizing etc. Remove and examine the engine oil filter for metal particles. Is the rear bellhousing accessory drive and implement pump damaged? 30-45 minutes to pull pump and check. 1) manually rock accessory drive gear to feel for gear clearance 2) turn implement pump by hand 3) start the engine without the pump installed NEXT?
Cut the oil filter open and inspect for particles, metallic or non-metallic....??
Deleted other steps just to save space. My thought process on what to check and what order to do checks are what I like to call the "Cheap Lazy Man's Method" In other words do the steps that cost the least in time or money first! Maybe pull air filters first and feel if turbo turns then go to pulling engine oil filter to see what is in there. But what ever order the checks are made it comes down to a simple process of elimination! Now if this was an engine with a ECM controlling things all bets are off!
NEXT? Check Turbo End and Radial Clearances per Cat's instructions.
Sorry had to find someone who was able to upload video to YouTube. Not very good on the technical side! This is with cranking. The machine is not even starting anymore
Turbo is 100%. Has done less than 200 hours since new
Have seen a Cat Reman Turbo fail in less than 10 mins under a stall test on a D 7G and it was a Cat reman motor, done by Cat servicemen, so just because its done less than 200 hrs means nothing, they can still fail. That clunking sound its got in that video don't sound good, you sure it hasn't got a broken crankshaft or camshaft, sounds like half the motor wants to go and the other half is a wee bit out of time due to a break in either one. Have seen a 6/71 GM still run with a broken crankshaft but very clunky. Hope its not but could be worth looking for
We checked the turbo. It is good. We cranked the starter with the tappet cover off and watched all the rockers lifting up and down. We have also checked the timing four separate times and it was fine. I think that rules out the camshaft. We will go back to the dozer on Monday to check inside the inlet cavity in the head for a rag.
Did you time it on #1 cyl. with both rockers rocking sure sounds 180 out
Dave you're mistaken, TDC #1 both rockers (valves closed) will have valve stem to rocker clearance. (Valve clearance set position) The opposite cylinder #6, the intake valve-rocker will just be closing and the exhaust valve-rocker will be opening > the exhaust stroke with rocker rocking downwards.
I thought that is what I said both valves closed on #1 exhaust closing on #6 he said in a earlier post that he timed it to#6 with #6 int and exh closed rockers rocking
Sorry, I was wondering if I was confused...from the thread replies you've posted your a good experienced mechanic. From the short video. Injection timing is way off, maybe trashed turbo. 1st check I would do is, CHECK INJ TIMING
No problem he said earlier that he run it with exhaust manifold off so I figure that eliminates the turbo I had one exactly like this and it was 180 off if this is not the problem then I would tend to agree with RG.Go13
Guys, I understand what you're saying about timing possibly being 180 out, but with the symptoms described in the OP does anyone have an idea how this might have happened..? And if the timing did slip somehow during engine operation, how did it manage to end up exactly 180 degrees off..?
The injector pump never slipped because I had to use 3/8 unf forcing bolts to get the front gear off the pump when I tried another injector pump. The timing is fine I am 100% sure
You should use a puller that pushes on the Center bolt rather then just forcing screws through the gear.
I am not assuming the timing is off exactly 180 degrees. The OP seems to understand the engine basics per his replies and is posting on HEF because the problem is not a normal-ish occurrence. I don't think a rag (1 rag) in the intake head passage would choke off enough air flow to prevent the engine from running. Large area. So has the crankshaft timing gear slipped? Throwing the timing out of whack? Service manual , 'Crankshaft gear...Do not over heat gear to more than 316C / 600F'... Old machine, could have a non-OEM crankshaft, gear used over that was heated with a cutting torch or non-OEM gear that is a bit softer etc. Small cam Cummins cam gear incorrectly installed without oven heating would SLIP; the hardened key would machine the gear's keyway wider....like over 1 inch.
The part that concerns me is where you said you timed it to #6 cylinder snd you have not replied any different. I will ask again did you time it to # 6 or # 1
Well I was thinking that it might of happened when he switched pumps because it ran and then it didn't run
The gear is keyed and if it did slip the valves should not be in the right position when the bolt is regaged in flywheel
Um, yep....looking for #1 TDC also requires using inj pump timing pin.
Listening to the video it sounds like only one cylinder is firing. I’m betting there’s an engine rebuild in your near future!
Thats what I reckon 379Pete, that why I reckon its a broken crankshaft but there is enough grip on the broken ends to still turn over but slightly out of time, will be interesting to see the post mortem results.
Broken crank would do it Nige, might be enough drive across the fracture to still turn over but some cylinders will be out of time, Seen a 6/71 GM in a Champion grader brake a crank, it still ran but not very well was knocking pretty well.
I've seen the broken crank as well on a 950B a lot of years ago. The engine just sounded funny and lost power. We didn't find the problem until my helper and I tore down the engine. He was on one side and I the other to pick out the crank. It folded in two and both of us couldn't stop laughing for some time.
Should put some money on this as to who can get the right answer. LOL. I am going for a broken crankshaft.
If it is a broken crank, they could put the timing bolt in the flywheel and rock the vibration damper back and forth and probably know for sure
That would do it for sure, seems like everything else has been tried and the easy fixes have been ruled out, might as well get serious, just glad its not my machine, but these things happen at times unfortunately.
I like the idea of installing the timing pin and rocking the damper.
Just to be sure I believe Nige is meaning to install the timing BOLT that threads into the flywheel, not the pin that goes in the fuel pump. Please feel free to correct me if I'm wrong. As a former boss like to say "I thought I was wrong once but turns out I was mistaken!" Only know of one Cat with a broken crankshaft, it was in a 992 loader at another quarry for the company. The boss at that plant did not want to believe the Cat mechanic so had be come over for a second opinion. I had one guy watch the flywheel and one guy watching the damper. Sure enough the damper end moved several degrees back and forth with no movement of flywheel. Also had broken cranks in a couple 8-V71 Detroits. One was in a IR Drillmaster and we ran that one enough to remove drill rod lower mast then after driving truck out of pit raise mast back up to pull engine. Both of those did crack the blocks at one of the main bearing bolt holes.
Ken, you're right. I should have said bolt. I suppose the other way would be to pull the starter motor and have someone watch the flywheel while the damper was rotated.
Its not sounding good.
If it is blowing smoke out of all cylinders even it must be broke toward the front I have had them break in the front before interested to see how this turns out please keep us posted Crock
Crank Arm breakage @ 1 is very common on in-line 6 engines, usually caused by vibration damper deterioration. On-highway engines you can used a pry bar to quickly determine if the crank is broken; 1/8" to 1/4" movement...also there will be a slight 'clack' @ engine start and 'bang-clack' @ engine shut down. Cat scrapers; engine downgrade over-revs guaranteed to crack-break crankshafts or drop valves (current and older engines). When we were still using D346s, cracked-broken cranks were stacked up like logs along side of the engine shop awaiting Cat's OR for new crank deal. Mechanical tack with tattletale...operators had their own key to set the needle back. ECM stopped that BS. Diagnostics via the internet can't hear it, can't feel it
So what was the out come, we are all awaiting the postmortem results.????
I would tend to think it's Valves failed on 1 cylinder resulting in nozzle damage, by failed I mean snapped off and whacked well into piston top possibly holed, the valve lift on the 3306 is 330 thou, the crank snapping usually only makes vibration and some clatter, it's not common to happen on the 3306 P.C. or D.I. engines as the crank has a strong shape and form with more chance of snapping a rod than cracking into 2 parts, the black smoke being caused by open inlet valve port/s tctractors
But he said he has black smoke coming out off all cylinders evenly
I did read that comment that is why I tend to think it's a snapped off valve head and damaged nozzle, this would blow crap into the inlet? it's not going to be dirt trapped in the fuel line it's going to be $$$$ costly. tctractors.
OP stated they tested each injector nozzle's spray pattern by hooking up the removed injector to the injection pump with a jumper line, one-by-one. (spray pattern was okay for each injector) Engine would still start and run at that stage. After fricken around with testing etc engine would no longer start. 3306 breaking cranks is rare, breaking rods and holing the cyl block common.
Any word on this problem
Bearing in mind the OP's location and the current political situation in that country I imagine that he's more concerned with staying in one piece than fixing his dozer.
Rhodesia / Zimbabwe isn't ever very stable; most countries where life is cheap (lots of children per family) also are not stable or safe... Nige, IMO, 99% of the HEF members are not aware of the current political upheaval happening in Zimbabwe. OR where is that country located, LOL
You're right about the political situation in Southern Africa Stan. I spent 15 years of my life in that neck of the woods, starting in Angola back in the civil war days. One of my current work colleagues is from Zim, so I get first-hand updates of what's going on, and it ain't good.
Wonder what the out come was. ????
As posted above, I would imagine that staying alive is the OP's biggest priority right now, not getting his dozer fixed. https://www.bbc.com/news/world-africa-46955725 https://www.bbc.com/news/world-africa-47028784