do I need a new head gasket if I only replace the head bolts on a Chevy 350?

Question

I think I want to replace all the head bolts on my engine after believing that one of the bolts failed while replacing the head gasket this afternoon. I believe that one of the bolts failed because it would only torque to 60 Ft-Lbs. After talking to other people, I believe that the bolt has lost its elastic properties. If I undo all the bolts and replace and re-torque then do I need a new head gasket even if I don't move the head?

How about if I just replace the bolts one at a time?

The rest of the engine is together and I really don't want to take the whole thing apart again just to replace one bad bolt.

Answer 1

I would replace one at a time and you should be fine if they are all torqued. If you take them all out the head could move and that would put a crease in the gasket

Answer 2

Martinmm stumbles around a little but he has it right. But - if you want to be safer. Determine if the bolt hold is stripped. You will have to do this subjectively. Look for threads in the threads of the bolt. If there, then the bolt hole is stripped. Otherwise, the threads might be stripped off the bolt (never seen it but it is possible). If bolt is stripped, replace it. If hole is stripped, remove head. Get heli-coil at auto parts and install it. Do not be concerned about it. I have installed many in Olds Diesels and the heli-coil will hold just fine. After installation of the heli-coil I would put the head back on with head studs and nuts, not bolts. More expensive but more positive. Reuse the gasket if money is that tight but it would be best of course to replace it.

Answer 3

replace then one at a time do not replace the head gasket again, the bolt could be bad od u stripped out the threaded end in the block...probably the bolt tho. yea get some aarp head bolts, do them one at a time and torque them started at the first torque squence and so on theres 3 torque sequences i believe hmmm 30 60 and 80 right? somethin like that

Answer 4

Once you have removed just one bolt you have released compression on the gasket and you face the possible problem on unseating the gasket, sure you can try but you are asking for trouble and why take the chance. And I agree with the other guy on possibly stripping in the block. The head bolts new are the strongest link in your assy compared to the threads in the block. Your block may be toast, and you will know when you change the head bolts and don't even think of a heli coil in the block, wont hold

Answer 5

those should not be torque to yield bolts so you do not have to replace them every time, but if it does not torque to spec, you could have a problem with either the head bolt or the block it self. a head bolt does not have a elastic quality, never heard that one. take that bolt back out and examine the threads and see if they are damaged, f they are fine then you are in trouble, that only leaves the block.

Answer 6

One bolt at a time. But I'd say you've stripped a bolt hole. That's a whole different deal.

Answer 7

pull one at a time this way there is no chance in moving the head just remember your torque order

Answer 8

if all is as you say then its not going to matter.take out the one bolt and replace it.tourqe it as was spec wise.just as if you did the whole set but only the one.even is even.and what the hell any way.right .it works or it don't but with out all the extra trouble too.