Opinions/Experience Sought on Seized Engine

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bbrinkley007

bbrinkley007

Joined
Sep 15, 2025
Threads
15
Messages
46
Location
Cotton, GA
Hi all,

I’m working on a seized engine from a Toyota FJ40 and could use some guidance.

The engine has been completely stuck for about 3 months now—nothing I’ve tried has moved it even slightly. So far I’ve attempted:
  • ATF/acetone soak
  • PB Blaster and WD-40
  • Heat
  • Impacting pistons (wood + sledge)
  • Breaker bar with cheater on crankshaft bolt
No movement at all.

I eventually pulled the engine, but since I couldn’t rotate it to access the pressure plate/flywheel bolts, I wasn’t able to fully separate it for mounting on a stand—so I’m currently working on it on the floor.

For context: I’ve been involved in a few engine rebuilds, but I’m definitely not an expert—just trying to learn and see what I can figure out.

What I’ve Observed​

  • When I pulled the head, everything looked surprisingly clean—almost like it may have been rebuilt not long before it seized
  • Cylinder walls show only minor rust and generally look decent (to my inexperienced eye)
  • Valvetrain (rockers/pushrods) had light surface rust but nothing severe
What did stand out:
  • I removed a rod cap and noticed the bearing oil hole does not line up with the oil hole in the crank journal

My Questions​

  1. Could a misaligned bearing like that cause oil starvation severe enough to seize the engine quickly?
  2. Is it possible this was assembled incorrectly (by someone inexperienced) and failed shortly after?
  3. Am I off base thinking this engine looks “too clean” for a typical seized motor?
  4. What should I check next to narrow down the cause?

Goal / Mindset​

This is honestly more of a learning project than anything mission-critical. Best case, I free it up and run it. Worst case, I learn what not to do next time.

The plan is to eventually throw it back on the original frame and have a rough, drivable “practice rig”—something I can weld on, tinker with, and not worry about hurting. You know… one of those: “Yeah, I turned that old pile of crap into a self-propelled pile of crap.”

I’ve included some photos of the bottom end as it currently sits with a closeup of the bearing I looked at, along with:
  • Head and valve train (from when I first started diving into this)
  • Pushrods/rockers (pushrods were rustiest thing I've found so far)
  • Cylinder walls (meh, not super rusty, not perfect either. I think they look ok)
Happy to take more specific photos if it helps diagnose.

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#3 looks pretty rusty. The bearing hole wont line up with the crank. The crank rotates and the bearing doesn't. I would tear down the engine since you this far into it. I would probably start removing caps. Check for rotation after each removal to find the offending journal or not. On the rod caps, once it is removed try to push the piston down in the cylinder. You might need to hit them with a hammer and block of wood or brass hammer/punch. Check to see if the bearing oil hole line up with the holes in the block or rods. Take note of everything. Once all the caps are removed and pistons moved down in the cylinders should be able to turn the crank. The pistons and rods and caps need to go back together as the came out. Are the rods and caps marked for location and orientation? Main caps marked?
 
Often, an oil starved engine that ran long enough to dang near weld itself stuck has heat discoloration evident on the rod caps.

If you take loose all the rod caps and you can't budge a piston to move, they are siezed in the bore.

If the pistons move, loosen the main caps and see if the crank will move. If not and it's not siezed in the mains, look further.

Pull the timing cover and see if there is something stuck in the timing gear teeth. Pull the timing gear if you can to separate the crank from the cam. You should be able to lift the crank out at this point.

Pull the oil pump and distributor, rocker assembly. See if the lifters will come out and if the cam will turn.

Something like a bolt jambed in the flywheel/clutch area? Pull the starter out.

Keep track of everything you remove for proper orientation if it goes back together.

Good luck, I hope you can salvage it and fix it without spending too much money.
 
Is the rust that’s shown in your photographs (esp. cyl #3) new after the teardown or was it there at teardown? Wondering about water incursion and hydrolock.
 
middlecalf said:
Is the rust that’s shown in your photographs (esp. cyl #3) new after the teardown or was it there at teardown? Wondering about water incursion and hydrolock.
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Most rust on cylinder head is after I took the head off and had cylinders soaking with used ATF and acetone. Just sitting outside in the humidity. For weeks.
 
Looks like a spun bearing maybe on cylinder 6. something got in the oil orifice and scored that area. Funny, but the bearings didn't show any unusual wear on 6 that my inexperienced eyes could see. However, all of the pistons were stuck to some extent from bad to worse to worser. Are they salvageable? I cleaned one up quickly with some diesel fuel and a wire brush and steel wool. But I'm not experienced enough to know if they are toast or not. Thanks for any thoughts. Oh, and the crankshaft spins just fine without the pistons connected. And I've kept everything together as originally assembled.

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The condition of the cylinder walls is going to dictate whether or not you'll be using those pistons.
 
pb4ugo said:
The condition of the cylinder walls is going to dictate whether or not you'll be using those pistons.
Click to expand...
Honestly, the cylinder walls look good from my initial impressions. I think finding the piston rings is going to be a bigger deal. Searching around it shows out of stock and discontinued everywhere.
 
Update: While cleaning the pistons and getting the old stuck rings out after soaking in ChemDip, I chipped the piston head between the ring grooves. I believe the cylinders only need a hone job rather than machining, but I am wondering whether this is worth continuing? Does anyone want to offer any thoughts? I'm losing faith in finding parts without investing more than it's worth (I realize this is the primary reason folks just go with an engine swap). I was hoping for rings and bearings getting my going again (head/valve cover gasket set was in the 40 when I got it). Are any of these parts worth salvaging and putting in classifieds if I do abandon my project?
 
bbrinkley007 said:
but I am wondering whether this is worth continuing?
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How much do you love the F engine?

bbrinkley007 said:
I'm losing faith in finding parts without investing more than it's worth
Click to expand...
"investing" more than it's worth is pretty much what we do here.

New bearings shouldn't be too hard to find, maybe even rings. I bet @OGBeno knows. Worst case, Total Seal will make piston rings for you
 
While anything can be done with enough money and determination, I think your engine is past what I would be trying to save.

The crank needs turned. In my world that would mean more bad is surely to be discovered. That, the cost and availability of parts, and the shortcomings of the F engine in general would have me looking for another engine. A 2F or conversion, take your pick.

Its too much time and work to do a poorboy engine overhaul and reinstall for something that will make disappointing power and have the short longevity of an engine not fully put back to in spec.

Sorry to be a negative nancy. The above comments are from an older dude that would rather spend more and not worry about every odd noise (and has driven an F engine til it welded itself together internally). If you’re a young dude who wants to spend as little as possible maybe its an interesting learning experience.

When I was a kid my used up second hand dirt bike was acting up (again) and my friends dad was trying to help. After a frustrating session he told me “shaneus, if you start with sh*t, that all you’ll ever have”. You can see that stuck with me.
 
Agree with everything @Its me shaneus said above. I would not put two cents toward that F. Let alone the time. A 2F shouldn’t be that hard to find if you’re looking to keep it Toyota or if not, do a swap. It’s a balance of value for money, unfortunately there’s not much value in an F, especially one that froze up.
 
yeah I would go ahead and fully rebuild that motor. or at least I think it would be your best bet for getting that motor going again and not having a constant worry in the back of your mind. as much as I really dont like seeing a SBC in a land cruiser, I think thats what I would do to my fj55 if the 2f decided to give up the ghost. I have seen it done really well here on mud. I always quote this one but @ClemsonCruiser had an epic one he sold on bring a trailer. 350-Powered 1967 Toyota Land Cruiser FJ40 4-Speed - https://bringatrailer.com/listing/1967-toyota-land-cruiser-fj40-25/ it was pretty cool looking and a rare color! I loved the matching valve covers too.

my plan has always been getting a marks adapter that keeps the stock trans and tcase location and then SBC with some sort of fuel injection kit. I bet it would be really fun. @pb4ugo you have a nice SBC conversion if I remember correctly too right?

also if you dont want to rebuild the f or do a SBC swap the 2f is the best budget option for sure. its what I have done to my fj55. It had a spun bearing when I got it and we pulled that engine and swapped in a 2f.
 
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Thanks everyone for your input and experience. I do believe I am going to scrap the idea of getting this engine rebuilt. I will most likely try to offer anything from it up on the classifieds. If anyone happens to follow up on this thread and have opinions or experience on how to best go about offering up parts, please do. I plan to keep whatever I can from this donor unit that looks useful for spares on my running '71 40, but the block, head, rockers, pistons, etc... are available if anyone needs them. I also will probably be looking to get rid of the frame (with title) if it is worth anything? I just don't want to haul this to scrap if that is a mistake someone, somewhere might regret me doing. I'm not looking to get rich, just to unload useful parts rather than tossing them. Just message me if you have any interest and I can get photos of any parts you might be interested in. (this engine had headers instead of the original cast exhaust manifold if that is of any interest to anyone).
 
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