OK, so how DO you get intake manifold screws out?

Without breaking them that is. Heat? PB Blast for a week, then heat? Small-bore air ratchet? Put a hex-bit socket in each screw and give 'em a WHACK before trying to turn? All of the above? I'm not touching mine (although they are cracked) until I know for sure beyond a shadow of a doubt that any cracks go all the way through...but I would like an idea as to HOW to do it without breaking any screws if possible.

 

I would make the effort to soak them every day with a few well placed shots of PB Blaster. Then I would make certain to use a short allen socket to maximize your torque.
I'll confess, I've never had an intake bolt break on me...ever. But I live in California and all of my XJ's didn't live on the shore so odds are good the corrosion never got a chance to set in.
If you know they are cracked, start saving for an upper end gasket set as well as new intakes. That way when you need to replace them, you'll be ready to yank the head if you need to in order to take it to the machine shop to have the broken piece removed. That is if you don't want to attempt the repair yourself (so folks here are mighty handy with such things, you could be one as well).
Best of luck to you Fitz.

 

I'm not touching them until I get my other XJ on the road either...in case I end up with a 2-week repair instead of a 3 hour task.

 

When I pulled mine any that didn't just jump out (there were 2) I used heat.

I used an oxy/acetelyne torch, #3 tip, smallest flame I could get. Heated the bosses until the screws turned easy.

I used the same technique on a broken exhaust stud.

 

Thanks Carl. But I'm still not sticking a piece of #12 insulated wire down the spark plug hole to hold open the valve. (Wrong thread, I know.)

 

#14 is too thin and #10 won't fit in the hole.

 

big-

when i was trying to change my boots, i ended up braking all but one bolt. i tried extreme to mild heat, i tried several differant penetrating lubes (i swear they never work for me) and the last thing i tried wich works ALWAYS (until the xj)......

i have an attatchment that goes onto my snap-on air chisel, and it is designed to hold any 3/8 socket.....i put the allen bit on the air chisel, and hammered away gently at first....then after fussing i let it rip wide open for about 5 minutes straight. the bolt was scorching hot, should have been hammered clear through to the other side of the head....but it still would not turn out and broke. tried it on all of the remaining bolts....nothing.

oh also on one bolt i tried welding a nut to the threaded shaft, but it just broke the bolt under it, and took half a thread with it.

 

Zookie- they use salt in Conneticut much ?
I think it's a salt thing. I just removed the intake Cap Screws from the Turbo bike. I sprayed them down with PB Blaster first, and even tapped on them for good luck. No Problemo !

 

salt............YES! not as bad as Mass, but bad enough! the roads are white in the winter time, and its not from snow.

 

Yeah, I'm thinking "all of the above." PB Blaster twice a day for a week prior, put the socket in the bolt, smack it; apply heat; use light-duty air ratchet to break loose. We shall see. Like I said, I'm waiting until the snow flies or the other XJ is road ready.

 

Maby some disgruntled japanese engine builder discovered locktite....lol