Ford 4600 diesel tractor

Question

I have a Ford 4600 tractor (3 cylinder diesel) that I have had for a few years. I have replaced the starter, alternator, cleaned up the contacts, changed parts of the electrical system, etc and managed to get it running well for 1 winter, start right away, run without problems (I use it to remove snow around my house). Then one winter it would randomly die. I tracked it down to a fuel flow problem, the tank filter. I cleaned the crap out the tank and filter on the intake, got the fuel flowing at a decent rate, tested the tractor and it ran fine. Winter came and snow. Went to start the tractor, found it hard to start, took me over 2 hours of trying, engine warmer on, running the glow plugs, external starter etc. Then it started. I left it running so that it could start to heat up the cab to defrost the windows. Then after a few minutes, I heard it start to slow down. I also saw nothing coming out of the exhaust, the cab had some inside it. Then it stopped. From that point, the engine had seized up, the engine will not turn. Tested the starter, works fine. battery is fine. I originally thought that it could have been water in the exhaust (the cap doesn't come down on it) and snow goes it. So thought that it could have been blocking it. Or water had gone in the engine.

So this week I decided to have a look (been seized for 6 months now), took off the injectors (cleaned them too) and had a look in, couldn't see any water. Tried to turn it over, without them in, it wouldn't.

Tried removing the exhaust manifold (is that what its called :) the part attached to the engine from the exhaust), a small amount of water ran out.

Oil is fine, its at max. Coolant it at a good level.

What could have caused this? I was planning on just taking apart the engine to have a look. I only know what i have read and looked up on youtube videos about engines. so not a mechanic, but I am very mechanically minded.

Do I need to strip down the engine?

A new engine isn't an option for this, its a rust bucket, the replacement engine would cost more than what I paid for the whole thing.

Thanks

Answer 1

I've re-read your post a few times.

If you cant turn the engine over without the injectors, assuming its in neutral and there are no other external impediments, then it does sound seized.

Id have one last go at trying to turn it over by towing it. Towing it in neutral and then in gear with foot on clutch should confirm that the gearbox, clutch, brakes & PTO arent culprits. If you drop the clutch and the tyres lock up thats pretty compelling evidence of a seized engine.

If the problem isn't outside the motor, then it has to be inside the motor.

From there youre looking at either seized pistons, crankshaft or something horrible around your crank/valve train. (Like a dropped or bent valve)

Id take the tappet cover off and check the valves. See if you can get a camera down the injector holes to look for scoring or a dropped valve. (Difficult if you cant turn the engine over)

After that its head and/or sump off to inspect crank bearings, crank and pistons. Hopefully you can do these without removing the engine. If not, the job just got a whole lot bigger.

Once you start disassembling its going to cost money to reassemble and its unlikely youll find anything you can fix for cheap/free. But if you are happy spending the time you might just get lucky yet.

I wouldnt write off the whole tractor yet. You might be able to get a 2nd hand engine that runs for a few hundred dollars. (Potentially cheaper than fixing your current engine)