Have read your posts with interest as I've crossed this bridge more than once recently. The only success I claim is my 1973 jeep cj5 258 I6. The jeeps engine was stuck but only from sitting , not from any internal damage . I was able to free it with pb blaster and time and a good yank from my '92 Cherokee . Thank goodness for manual transmission . It's running .
Well , that's my success story , but I've two of dismal failures. One was a stuck solid ford 3.8 V6 which ended up a sailboat anchor and a 455 olds engine which we found only by means of disassembly that a cylinder wall was rusted through . So much for a vintage power plant .
if your engine does hold its coolant level , I believe there should be hope .
the olds 455 didn't . That was our first clue . My friend was filling the radiator of his not so prize '69 olds cutlass conv. and asked " how much water do these engines take ? " . We laugh now but I got a sick feeling as I heard liquid entering the crankcase while I was installing a starter .
I believe that time should prevail with the use of diesel fuel , which is supposed to be the best solution since it has properties that prevent slugging and I believe rust inhibitors as well .
i realize it's been about two weeks since you've started this procedure and thus far haven't been successful . Before removing the cylinder head , have a plan first . Fully realize as well your asking for advise here at jeepz.com. I will say from all I've heard of this subject as well as my experience that every stuck engine has its own story . Some are just rust around the piston rings from broken down engine oil moisture or water has made its way down an intake via the carburetor and through an intake valve .
A lighted bore scope would be great about now but a plan to deal with rust is better .
No doubt you've heard of all the concoctions and home brews for this task .
can tell you that trans fluid and acetone didn't work for me but we didn't give it much time either.
my only question is , with an empty crankcase ( oil drained ) , is there any sign of diesel fuel making it past any cylinders or has any cylinder's level not dropped ?
All it takes is one cylinder to cause the engine to not rotate. If it is in fact one , that will be the focus of your next plan . Compressed air may be helpful to force solution through? You may still need to remove the cylinder head but there is another plan of attack . It is easier with the engine out and upside down but with the oil pan off , you would have access to the cylinders from below the rings where a penetrating oil or what ever is elected to proceed with its task can be applied . Attacking from both top and bottom of piston bores gives a better chance . I don't know if the 134 engine has more compression rings or even oil rings than other engines but if so , that is just more surface to fight .
if you elect to pull this engine in an attempt to try it the way I've posted , there is pluses to this .
you may be persuaded to remove the cylinder head after enough attempts of soaking the engine and tempted to hammer on the stuck piston(s) with a block of wood . Should you go this route , please use restraint . Your not trying to hit the bell at the carnival . Piston domes can shatter as I'm sure you know .
I would first investigate the level of each cylinder to see if any progress was met .
hoping that the least amount of cylinders are a problem and maybe a strong penetrant will yield results with a little help from a good pull from another vehicle . Use restraint too. Find strong anchor points . Don't rely on bumpers . I don't think using an axle is advised either .
If the engine isn't free with reasonable force , more time of soaking or an engine pull is in order .
youll be the judge . One good thing about the engine pulled is that it's one step closer to rebuild or replacement if warranted . That's what we figured on in the case of the '69 conv.
Not wishing for you to have to pull or even replace the existing power plant but don't want to see you in denial as we were . Hey , hope you can get your hands on a good lighted bore scope .