Hi, the PO of my GC 93 4.0l has broken the thread for the back bolt at the intake manifold, it was filled with some type of silicone or something. Is it a hard job to make new threads back there?

 

Do you mean the stud broke at the rear of the head? It will be a pain to fix correctly, but it can be done. You have to remove the broken stud and with any luck the threads in the head will be ok, but if your luck is anything like mine, the threads will be damaged. Then you drill out the hole and repair it with a heli-coil. It's going to be a tough job because that is a tight and hard to reach area. Leaving it broken will only cause the gasket to burn out and leak.

 

no, its not broken. I got the bolt out, but the bolt did have a 1mm silikon arround the threads (is the name thread?). Its missing threads inside the cylinder head where the bolt goes in (the back upper bolt for intake manifold, the number 11 in tightening sequence). Could i only buy a thread something tool that i screw in and got new threads, or do i need to clean out the hole first?

 

if the threads are gone, doing as Busted suggested with the helicoil is the best way.

 

ive had to repair several threads on Small/Big block chevy motors and i would highly recommend pulling the head. you already will have the intake and exhaust pulled off. pop the intakeand the head bolts. and you can replace the head gasket while your in there and take a peek down inside the motor to see how things look. and you will have full access to it. i have NEVER used Heli-Coil just not my thing. we always drill the hole a little larger and re-tap the hole with a thread die and drill the hole on the intake out a little and put the larger bolt in it. plus youll have the head and valve cover gasket replaced.


If your going to do it, make sure you do it right the first time so you dont have to come back to it 10k miles later

 

ok, if i remove the head, do i need to have new head bolts? I dont know if the bolts have been reused before. Could i have the head of for 2-3 weeks, or will it start to rust inside the cylinders, if i need to order bolts or if i dont have the correct head gasket (i have a new gasket, but i dont know 100% that it is the correct one). Do i need to remove the valves or could the valves with the valve springs be attached to the head when i remove it?

 

If you have to have the head off spray the cylinder walls daily with wd4o and rotate the motor a few times. The head bolts im not sure id fair on the safe side and get new bolts. And the valves will cone out with the head its all attached