The “What kills an F-block?” thread

[RockDoc]

Call it killed, call it tired-out, call it whatever…. In the experience of those who have dealt with rebuilding their Land Cruiser 6, or a “forced” engine swap, what was the ultimate cause of the engine’s demise?

Burnt valves?
Slipped bearings?
Blown head gasket? Other gaskets and seals?
Cylinder wear and loss of compression?
Component failure?
Extreme overheating?
Collision?
Hydrolock?

What could have been done (if anything) to avoid or delay engine death? Please specify what engine (F, 2F, 3Fe), and vintage if it is relevant. Please post links to relevant threads (diagnosis, fixes, rebuilds, etc.)

Educate those of us with well broken-in, but still strong engines on what we should be doing and keeping an eye out for. Filtration, valve adjustment, over-looked maintenance….

 

[DirtyLittleSecret]

They die of old age.
They die of stupid people.
They die of humiliation from other cars on hills.

 

[bigbrown]

losing your oil galley plug.

 

[inkpot]

Howdy! I have no clue what caused it, but the crank broke on mine, right at the oil hole on the #5 rod journal. I actually kept it running for over 4 months like that, before I finally pulled the pan and tracked down the reason it was not running very smoothly. John

 

[Dave-T]

2F, detonation

 

[esh]

sugar!


this game is fun!

 

[Spook50]

losing your oil galley plug.

That's what almost got me. Drove 5 miles dry of oil before I even realized it. Pissed me of because I knew it was going to happen at some point so when my eyes weren't on the road they were on the oil pressure gauge.

 

[Gutterpunk]

knew it was going to happen at some point? Is there some reason this is inevitable?

 

[bigbrown]

knew it was going to happen at some point? Is there some reason this is inevitable?

mine was secure until i had the head redone. then it began to work its way out. i also almost lost my engine because of it.

lots of threads on fixing it for good.

 

[Spook50]

knew it was going to happen at some point? Is there some reason this is inevitable?

It's pretty common to happen when the engine gets up in its mileage, and since I was using a lighter viscosity of synthetic oil, I had a feeling it was going to work its way out. sure enough, it popped out the one time I wasn't paying attention. Ain't that the way it always happens?

 

[RockDoc]

sugar!


this game is fun!

Ouch!!!! Not sure how we avoid that one!

 

[RockDoc]

losing your oil galley plug.

https://forum.ih8mud.com/showthread.php?t=113830

A starting point for learning more about the oil gallery plug of death.

 

[Heartworm]

I agree with Dave-T about detonation. I bought mine from a guy who drove it 70 mph all the time and he killed it on a long pass. He must have been letting it lug in too high a gear. It knocked a hole in the #4 piston. I would say that if your engine is pinging, you need to deal with it.

 

[roscoFJ73]

My 3F cam shaft wore out at 200000 miles and I couldnt adjust the valves. The diffs and gearbox bearings also needed replacing about that time.

I bought it as a basket case off some young guy who had lost his lic and was broke.
I dont think he ever changed the oils in the 2-3 years he had it.

 

[Trollhole]

https://forum.ih8mud.com/showthread.php?t=113830

A starting point for learning more about the oil gallery plug of death.

https://forum.ih8mud.com/showthread.php?t=191622

 

[RockDoc]

Thanks Trollhole

well illustrated!

Looks like this applies for the F, 2F and 3Fe.

 

[nikos8]

sugar!


this game is fun!

I was watching myth busters and sugar in the gas tank turned out to be a myth. Overheating has done it for me.

 

[esh]

My dad's motor has blown up twice because of that.. but it was a Chevy 4.3.

 

[NocalFJ60]

The vacuum passage bolt in the bottom of the carb is what pushed my engine over the edge. It fell out and took out a push rod and scraped the piston. Before that happen I was getting low compression in cylinder 6 from bad rings which I believe to be caused by the PCV vacuum line getting clogged completely which caused the crankcase pressure to increase which did not help the rings.

 

[dmede808]

My F engine (1971 fj55) spun a bearing on the first leg of a long road trip. Real bummer. But I can say that prior to that happening I knew the engine was dead tired by watching my oil gauge. She had fine pressure when driving but once warm and at an idle it would drop well below the lower pressure line.

I agree with what was said above about the cause though... it's just old age in most cases.