DIESEL EXPERTS! Diesel Engine Diagnosis...

I was brush hogging today and I stopped forward motion then shifted into reverse and the engine started knocking and lost power. This was followed by heavy exhaust smoke. It was almost dark, so headlight diagnosis of smoke color was a little trying. It looked blackish-greyish-whitish.

My father suggested draning the fuel filter and the sump on the tank. He thinks it is water in fuel. It has rained for weeks and is humid (100% RH). When I started it back up it was idling then would start knocking and smoking then clear out for a moment and start smoking and knocking again. It is kinda intermittent.

This is a D-188 on a Farmall 504.
Thank you,

CT

Charles: Sounds like a sleeve with top broken off, they do give fair warning. Some knocking then suddenly the piston sucks the sleeve down into crankcase. Not a problem until piston comes back up.

This was quite common on D-282 and D-188. I'd pull the head PDQ. My 560 did this and the young lad using it on silage blower at silo, left it running and went for help. When he got back, hole in side of block size of your head. Two pistons and associated debris scattered as far as 50'.

Hugh, I know you are very knowledgable with the Red Iron. But what you said here kinda scares me a little... I was hoping for water in the fuel. I am getting ready to hike back there (back forty) and drain the water sump in the tank and change the fuel filter.

If it doesn't clear out I'll limp it back home and pull the head PDQ. Damn.

CT

Hugh knows his stuff but I"ll just stick my oar in to say that if it stopped knocking (if only briefly) after you restarted it, then I have a hard time believing you dropped a sleeve.

Hugh, if worst came to worst and draining the filter and tank doesn"t help then might it be easier to confirm by dropping the oil pan as it"s quicker and easier (I think) than pulling the head?

Good luck,

Sam

Charles: I may be wrong, however you've had fair warning. It will become hard to shut her down in the length of a stroke, even at low idle. I don't think your that fast.

If you go back in the archives to around 2003, this subject received a lot of discussion. Dropping sleeves is quite common on D-188 and D-282 engines. Those who heeded the warning saved their block.

Sam: I suppose you have a point, however I think a broken sleeve could stop knocking for a short period.

Having said that, after 26,000 hours with D-282 engines, broken sleeves are not the only knocks I've heard. You realize of course D-188 is just 4 cylinders of the D-282 engine.

I had 656 bend a valve push rod once. Young lad that was running 656 on haybine at time noticed it, but didn't seem that bad from seat. I had just finished milking cows, came out of barn to hear 656 knocking badly as he drove towards me. As he turned at the headland and started to go the other way tractor sounded quite normal. I proceeded to field with haste. Out front and hearing it through the grill, you'd swear it would fly apart any min. Behind or in the seat you'd hardly notice it.

Another knock I heard was 560 working on forage harvester, roughly 9,600 hours on engine. It would develop a sharp little knock several times per day, and each time it would fade away to nothing. We finished filling silo, however once at night we noticed our little knock was acompanyed by a shower of sparks out the exhaust.

We pulled the pan and head after silo filling. Two pistons had ring pieces missing, with pick marks in top of piston and in head. Technician I had decided rings had been breaking up, coming to top and hammering them until the parts were small enough to blow through the valves and out the stack, thus source of sparks.

We installed a piston and sleeve kit, and those were the sleeves that broke after 1,500 hours. Technician was not thorough enough on sleeve sizes. I was told afterwards there is a difference in sleeves, and they must be ordered to fit the particular block.

It's funny how some of these sounds travel in old iron. I've just gone through my new (to me) Farmall 300, hunting what sounded for all the world like diesel knock in an old mechanical diesel.

I couldn't make it go away by pulling a plug wire and sometimes it would sound like the fan hitting something. It turns out the camshaft was so loose inside the cam gear that the valves would be opened and then the valve springs would force the cam ahead and the valves would snap shut. It was the valves snapping shut that was causing the noise.

You could be right about a broken sleeve stopping knocking for a bit. My MF-35 had two loose sleeves and they knocked worse before it built oil pressure when it first started (figure that one out if you can).

Sam

I drained the fuel tank sump, decent. I drained the fuel filter bowl, water. I pulled the filter out, bottom cork gasket swelled up (water?). Cleaned it up and turned on the tank valve. Minutes later, no diesel at the top bleeder on the filter cap. I disconnected the fuel line at the tank valve and had a minute dribble. I rapped on the valve with a 3/4" wrench a few times and diesel flowed... Not good. Hooked the line back up and glow plugged the engine for about 2 minutes to make SURE it was hot. Fired off quick, but knocked a little. Let it idle about 5-8 minutes and wile knocking I eased the throttle up a little at a time. Lo and behold, after about 1/2 throttle it stopped. I progressed to WOT and no knock? Sharply went to idle and knocking began, back to WOT and smooth (some light missing, but been that way for years).

I got the tractor 3-4 years ago and it had a light miss under load. I used about 3x recommended doseage of (Diesel Kleen?) injector cleaner and cetane booster for several tanks. It ran like a top. I stopped using it about a year ago and have long since ran several tanks of hwy diesel thru it.

Once I got it back to the shop, I could see the exhaust smoke. It was grayish-black when it would miss and a lot of it. So missing only below 1/2 throttle and grayish-black... Could it be an injector not seating or stuck flooding a cylinder at part-throttle and using all the fuel at WOT?

I have been mowing (bush hog) a lot lately at about 1/2-3/4 throttle, not WOT. When I gap down on it after it is warmed up occasionaly I'll see some sparks come out of the exhaust. I have heard these engines like to be loaded and not babied around. I have provided a lot of easy, low RPM work on it. Could it be carbon build up and I need to dump some Diesel Kleen to it and run the Sh*t out of it?

Thanks,

CT