Hello all, I am investigating why the engine is seized in my newly acquired ‘86 XJ6 (yes I knew it was seized when I bought it). Initial attempts to break it loose via solvent soak in the cylinders and turning via crank bolt were unsuccessful. Oil looks good, spark plugs look good, and I took off the camshaft covers and they look good as well. Timing chain seems ok. I want to get the head off but that requires unbolting the camshaft flange, so since I can’t turn the crank I can’t figure out how I’m going to do that. Is there another method?

Thank you in advance

 

Many years ago, I bought a seized MK2 3.8. It had been siting for some years and there was no history of the car.
I tried all of your tricks but it was locked solid.
By sheer chance I applied force to rotate the engine backward and it came free!!!!!
It turned out that somebody had dropped one of the retaining nuts used to hold the camshaft sprocket when taking the head off and it had lodged in the upper timing chain where it meets the bottom drive sprocket.
I just wonder if something similar has happened to your car.

 

Yeah, I tried in both directions. Won’t budge either way.

 

I have found the best fluid for freeing up siezed engines that have been standing for a long time is Coke or Pepsi. Not the sugar-free stuff but the traditional version.

Just put an eggcupful in each bore and wait overnight.

If you have ever put an old coin into a cup of coke you will have seen how good it is at cleaning up corrosion.

 

The reason is, of course, that both contain Phosphoric Acid which attacks oxidized iron & aluminum. If you are going that route, maybe Water Softener Cleaner, diluted Phos Acid, would might be a better choice. Seems radical on it's face....but !

 

I managed to get those cam flanges unbolted by stuffing a rag below (so the bolts don’t fall into the block) and working them loose with a combination wrench. The last bolt was behind that holding bracket but once the other three were removed I could move the sprocket up the holder and remove the last bolt that way. Problem solved - not as bad as I feared!