Seized engine? Need some advice.

[Kernopelli]

Son has been using the tractor for a landscape job for local school district. Mitsubishi MTE2000D...nearly identical to a CIH 254/255, biggest difference is the CIH's used Mitsubishi's K3E and mine has the K3F engine. Tractor running fine, fluids fine, no unusual noises, started w/o using glow plugs despite cold temps. He loads the tractor on the trailer and intended to leave it idling/warm up while chaining it down but when he moved the throttle back to idle, he said he instantly knew he had moved the throttle too far and accidentally shut the tractor off.....done the same thing myself a million times. Throttle is how this model shuts off, no solenoid, switch, key position, etc required. Less than a minute later he hops back on it and tractor WILL NOT turn over. It has every indication of being locked up. The starter engages well and attempts to turn hard. I have tried to turn the crankshaft w/ ratchet and cheater bar after taking the glow plugs out and she won't budge. I've made certain there's no hydraulic pressure on the pump. Transmission appears fine and not a factor and clutch does disengage engine from trans when pushed in. I dropped the oil pan and can not see anything unusual. What I can see of cylinder walls looks good, cam and lobes looks good and can't tell anything unusual about crank. Rods and pistons don't show anything apparently wrong. Took the valve cover off and there doesn't appear to be any bent push rods, I can push the valve stems and they move freely so there doesn't appear to have been any piston/valve interference issues. The only reason I haven't taken the head off yet is I'm certain a new head gasket is going to be pricey and possibly not easy to get.....I wanted to get some input before progressing.

After seeing what I did ( nothing unusual) I decided to loosen the 4 crank main caps thinking if the main bearings were seized this would likely allow me to turn the engine over by hand...engine is still tight as a drum. Is my thinking right (If crank bearings were seized, would loosening the caps allow me to spin the crank by hand)?

What next? As mentioned, I'd like to try to put off taking the head off just yet. I can take the timing cover off and see if there are any gear issues. Take the hydraulic pump off to make sure it hasn't imploded some how. After that I expect it's head time and progressing on to a normal tear down? I really want to hit all possibilities before I yank this engine and start tearing it apart. Need some advice?

 

[tcartwri]

Make sure the Bendix gear on the starter has retracted before you go any further. Are any of the caps or mains discoloured?

 

[Cat_Driver]

Chances are it's NOT the engine. It would take a lot more than that to seize an engine.
Now if you said you had no oil in it and ran it with sand, maybe, but even that would take a lot of work to seize an engine.

Take a look at this. No oil and sand in the engine and he still had a hard time blowing.

[ame=http://www.youtube.com/watch?v=waj2KrKYTZo]Volvo Cash for Clunkers Engine Disabling - YouTube[/ame]

 

[Kernopelli]

Make sure the Bendix gear on the starter has retracted before you go any further. Are any of the caps or mains discoloured?

Starter is functioning right...already checked. n fact, I had a N.I.B. back up that I put on and tried too. I didn't actually take the caps off, just loosened...sounds dumb now that you ask. Taking baby steps on this and was thinking that loosening would probably allow crank to turn if it was a bearing issue. I'll take the caps off and investigate.

Chances are it's NOT the engine. It would take a lot more than that to seize an engine.
Now if you said you had no oil in it and ran it with sand, maybe, but even that would take a lot of work to seize an engine.

Take a look at this. No oil and sand in the engine and he still had a hard time blowing.

Volvo Cash for Clunkers Engine Disabling - YouTube

Yeah I know. I had originally posted about this in the Mitsubishi forum and hit on your point there. It is beyond my comprehension that an apparently good running engine can lock up so quick AND do it at the precise moment it is being shut off.......but I haven't found anything else to explain it yet. That's where you guys come in. Work schedule/OT and other commitments are making it hard to put much time toward doing much yet. Would like to hear any and all conceivable things to check before I dig too deep into the internals. Also trying to avoid doing unnecessary steps that will require expensive and hard to get gaskets, etc to put back together.

What would you be checking?

 

[Hooked_on_HP]

Since all the fluids were ok and it wasn't knocking I doubt the engine is seized. I will assume you unloaded it off the trailer. That tells me the trans isn't locked up Did you check your TPH. How about the quick disconects fot the loader it you have one. I would guess you have a hydraulic problem. Do you have a deverter valve for aux. hyd that could have got activated and are dead heading. You might also remove the starter to make sure it isn't siezed.
Bill

 

[grsthegreat]

again id first try a different battery and check all the ground attachments before id worry about the engine.

Just jumping a bad battery or a bad connected groung wont fix the issue alot of times..especially a shorted battery

 

[Hooked_on_HP]

Forget the starter. You posted while I was typing. Have you tried to turn the engine backwards,
Bill

 

[tcartwri]

Linkage on the fuel pump is intact, and hasn't been messed with?

 

[crazyal]

Another thing you can try is removing the belt for the alternator. I've seen bearings seize on them and act like the engine is locked up.

 

[Kernopelli]

Since all the fluids were ok and it wasn't knocking I doubt the engine is seized. I will assume you unloaded it off the trailer. That tells me the trans isn't locked up Did you check your TPH. How about the quick disconects fot the loader it you have one. I would guess you have a hydraulic problem. Do you have a deverter valve for aux. hyd that could have got activated and are dead heading. You might also remove the starter to make sure it isn't siezed.
Bill

Correct on all counts..all have been checked.

again id first try a different battery and check all the ground attachments before id worry about the engine.

Just jumping a bad battery or a bad connected groung wont fix the issue alot of times..especially a shorted battery

I have hooked two very new batteries in 12V tandem and she wont budge. Even tried a new starter I already had.....unfortunately, whatever is binding the engine is way more than a good battery and starter can overcome.

Linkage on the fuel pump is intact, and hasn't been messed with?

Yes and Nope

Another thing you can try is removing the belt for the alternator. I've seen bearings seize on them and act like the engine is locked up.

Tried turning the engine w/o glow plugs in so compression wouldn't be an issue and belt off. Used an S&K 1/2" ratchet with a 2'+ piece of DOM tubing on the handle to get a 3'+ cheater and tried forward as hard as I dared, (WAY more than it would take to turn a healthy engine over). Backwards until the crank nut came loose.

I did just go out and took the starter off and cant see anything unusual on the flywheel side. Took hydraulic pump off and it was OK- turning freely. I took the 2 center main crank caps off and the bearings and crank journals look excellent. After seeing that I decided it's probably not a crank bearing issue. I decided not to take off the more difficult end caps. They are part of the block and with the engine still "in frame' I didn't want to risk not being able to get them back in easily.

I took the radiator out while I was out there and tomorrow I'll pull the crank pulley and take the timing cover off and see what the situation is there. If that's OK, It's either split the tractor to see what the flywheel side looks like fully or the head is coming off (more likely to be what I do).