Farm Pro 2425 Engine Knock

NoCashValue · Oct 9, 2019

Hi, new to the forum, and dying to get some experts to weigh in on my problem. I picked up a non running Farm Pro 2425 a few weeks ago. I don't really have any experience with tractors or older diesel (mechanical injection) systems but I thought I would give this a try.

The fractor is a 2004 model, with the Y385T diesel engine. The wiring on the tractor has been hacked up by the previous owner, so none of the gauges were operable. I fixed up the ammeter, glow plug harness and tachometer and started trying to get the engine to start.

When I got the tractor, it would turn over but wouldn't start. IT had been sitting for a few years and I was told it was running when it was parked but I doubt that after what I found getting it repaired. I started by putting fresh fuel and purging all of the fuel lines to the injectors. After a lot of trying, I was able to get it to start, but the throttle had no effect. Sometimes it would start and run up to mid throttle, sometimes just to a rough idle, and it would eventually die off on its own. Never enough power to move under its own power. I was starting to think the head gasket was suspect (it was smoking heavily) and it seemed like a reasonable possibility.

I buy a new head gasket and plan a weekend to do the replacement. When I pull the head off the tractor I find what looks like a fairly new condition head gasket, with no obvious signs of damage. The cylinders don't look great, but they didn't show major signs of damage either. (see below) I cleaned up the head and block and installed the new head gasket. As I reassembled the head, I noticed the fan pulley seemed loose and found the bearing out the water pump were shot. Ordered a new water pump and waited for the next weekend to continue.

The next weekend, I get the new water pump installed and start up the tractor. It still struggles to start and has similar symptoms as before. I decided that the injection pump must be at fault and try to diagnose. In the process of checking the timing, I find that the keyway on the pump shaft has been sheared off and the bearing on the injector pump cam is also damaged. I end up purchasing a new injector pump and installing that the following weekend. I do my best to roughly time the pump using the terrible marks on the flywheel to approx 15 degrees BTDC. Button everything up and start the tractor. It is MUCH easier to start now, and the throttle actually responds properly. The tractor is smoking a fair amount of white/grey/brown smoke at all times though.

I have let the tractor run for about 5-10 min at a time (at idle) after completing the pump replacement as I check over the remaining leaks (radiator hose) and ticks. After about 5 min of idle, if you throttle the engine at all it develops a knock. As the engine gets warmer, the knock is present at all times. It sounds like a a gas detonation knock which concerns me enough to shut it down before to long of running in this condition. Let it cool and start it again and the knock is gone.

I'm planning to install all new functioning gauges this weekend. I suspect the thermostat is faulty and not letting water flow to the radiator (I've left the rad cap off as it warms up and have not noticed a significant change in flow) which may be leading to the knock. I feel like it is temperature related.

I am also concerned that the fuel injection timing is incorrect. I don't know if this would contribute to the knock, but I believe it is the reason for the smoking.

I've uploaded a few videos to YouTube fore reference. The first video is the cold start up and running for a few minutes. The second video is a few minutes later after everything has warmed up and the knock is occurring.

Farm Pro 2425 Engine Knock 1 - YouTube

Farm Pro 2425 Engine Knock 2 - YouTube

Coolant leaking in the video is from a leaking upper radiator hose. I have since fixed this and verified there are no leaks on the engine. Tractor has all new fluids and filters.

Wondering if anyone has any pointers on the knock? Is this a crank bearing knock? Or could this be fuel related due to engine timing and or overheating.

Thanks in advance for your expertise.

Eric

Affordable · Oct 10, 2019

Without seeing the tractor in person the knock may be from a bad fuel injector , if it was a rod bearing it would knock all the time, the white smoke may be from a Broken Oil ring most of the time white smoke is associated with moisture or water in the fuel or oil ,we have seen this a lot on these engines, do you have blow by ?Take the oil fill cap off while its running .It sounds like your timing is pretty close, there are some adjustments in the slots on the gear on the front of the injector pump

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company
979-865-4002

Bayfisher · Oct 10, 2019

the noise i hear sounds more like valvetrain noise, chk the valve tappet clearance again, also ur pump timing could be off as well, is there an exhaust leak somewhere.

NoCashValue · Oct 10, 2019

Affordable said:
Without seeing the tractor in person the knock may be from a bad fuel injector , if it was a rod bearing it would knock all the time, the white smoke may be from a Broken Oil ring most of the time white smoke is associated with moisture or water in the fuel or oil ,we have seen this a lot on these engines, do you have blow by ?Take the oil fill cap off while its running .It sounds like your timing is pretty close, there are some adjustments in the slots on the gear on the front of the injector pump

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company
979-865-4002

Hey Tommy, thanks for the pointers. There is definitely blow by happening. The breather pipe that exits near the bottom of the engine is puffing the grey smoke and if I pull the oil fill cap off while it is running I get some as well. If the oil rings are the issue, would it be as simple as removing the pistons, re-ringing and honing the cylinders?

I may not try to play with the timing any further if you think it sounds close to correct. I thought the smoke could be from timing but it seems like you are suggesting it is more likely burning oil than fuel.

Thanks - Eric

NoCashValue · Oct 10, 2019

Bayfisher said:
the noise i hear sounds more like valvetrain noise, chk the valve tappet clearance again, also ur pump timing could be off as well, is there an exhaust leak somewhere.

Hi Mike,

I don't think there is an exhaust leak. I did replace the gaskets when I pulled the head. I'll double check the valve clearances when I get the gauges installed this weekend. I did a rough check with a feeler gauge and tightened some of them up that were way out, but I was working quickly. I believe I had the intake set to .010" and the exhaust set to .012" Would you expect the valve noise to increase as the temperature came up? I'm still worried it is overheating due to low water flow.

Does anyone know if I should be able to see some sort of movement with the radiator cap removed once it is up to operating temperature?

Thanks!

Eric

thepumpguysc · Oct 10, 2019

U replaced the inj. pump & NOT the injectors.?? WHY??
If u have a sticking injector.. it will get noticeably worse as the engine gets warmer..
To diagnose/narrow it down .. get the engine knocking & loosen the line at the injector 1 & a time & listen to the knock..
No change.. retighten that line & move to another until u find the suspect cylinder..{no knock}
Once u narrow it down.. remove THAT injector & move it to another hole.. FURTHEST AWAY FROM THE SUSPECT CYLINDER..
& do the test again..
IF the knock moves to the other hole, you KNOW its the injector..
IF it stays w/ the original hole.. that's bad.. but atleast u narrowed it down..

Bayfisher · Oct 11, 2019

NoCashValue said:
Hi Mike,

Would you expect the valve noise to increase as the temperature came up? yes

Bob Rooks · Oct 11, 2019

NoCashValue said:
Does anyone know if I should be able to see some sort of movement with the radiator cap removed once it is up to operating temperature?

Yes and no, it will depend on the position of the thermostat. With the thermostat closed you will see little to no flow (depending on what the by-pass circuit allows). With the thermostat fully open you will see rapid flow. If the thermostat is modulating the flow will be moderate.

NoCashValue · Oct 13, 2019

Alright, I had some time to work on the tractor this weekend, first I installed a full set of functioning gauges and new oil pressure sensor and water temp sensor.

Before starting, I readjusted all of the valves to spec, which I believe I had done incorrectly the last time. I had incorrectly identified the exhaust valve as the intake valve and adjusted the valve clearance backwards (IE, intake clearance used on exhaust and vice versa) . Adjusted all intakes to .009" and exhaust to .011".

Buttoned everything back up and started it up. Still has trouble starting and needs to crank for a while. I don't have the glow plugs hooked up but maybe some heat would help out there (it isn't very cold in AZ though....) Once it is started I want to say the valve noise has been reduced. There is still a knock similar to the first videos I posted which seemed to develop after it had been running for about a minute. The good news is that it is showing good oil pressure. I let it run until the water temp gauge registered and settled around 60C. There were no significant changes to the way the engine was running during that time. I was also able to remove the radiator cap and observe some amount of flow/turbulence that has convinced me the cooling system is working properly.

With a little more confidence after marking the crank pulley and setting the valves again, I am going to go and re-check the timing. I am starting to lean towards the timing being too far advanced. It seems reasonable to me that the hard starting is due to the timing and the knock could be more of a fuel knock. If that is the case, I am also hoping that adjusting that back may reduce the amount of smoke as well. The last time I did the timing I thought it was somewhat subjective to when you decide the fuel port is starting to push fuel, so I may make a video of what I am seeing so that others have a reference in the future (assuming I do this right). I may do a compression check in the future as well, but I don't have the adapters to fit into the glow plug ports. I think that would be able to confirm a good portion of the smoke is blowby from bad rings.

I'll report back what I find in the next few hours. Thanks again everyone for the suggestions.

piper184 · Oct 14, 2019

60°C (140F) seems a little cool. Could that be causing incomplete combustion and thus the smoke?
Also I think a leaking injector could cause the same conditions. I don't know how to test for that other than remove and take to a shop that can test them. I suppose you could buy a new injector and replace them one at a time to see if it improves the situation.
My 284 enjoys a little shot of glow plug, even at 40°F. Mandatory at anything below 20° and block heater required below 0 F