Help! Intake bolt thread issue

[pdeason]

I am doing an intake manifold gasket replacement and was running a tap through the bolt holes to clean them out. The last one did not feel right from the start so I did not go very far before backing out. I tried the bolt in the hole and it will only go in about 3/8-1/2 inch before stopping. I assume I must have messed up the threads with the tap. What are my options?

 

[ned pepper]

I am doing an intake manifold gasket replacement and was running a tap through the bolt holes to clean them out. The last one did not feel right from the start so I did not go very far before backing out. I tried the bolt in the hole and it will only go in about 3/8-1/2 inch before stopping. I assume I must have messed up the threads with the tap. What are my options?

is the hole full thread, into water jacket, or blind? meaning it has a bottom. I would run a wire "drill" tool thru it to brush it out, no reason to use a tap. it is aluminum head.

some bolts on the runners are blind holes, use shorter bolts. not sure about intake.

 

[pdeason]

is the hole full thread, into water jacket, or blind? meaning it has a bottom. I would run a wire "drill" tool thru it to brush it out, no reason to use a tap. it is aluminum head.

some bolts on the runners are blind holes, use shorter bolts. not sure about intake.

It is a through hole (number 9 in the torque pattern). It is not a water jacket hole.

 

[ned pepper]

It is a through hole (number 9 in the torque pattern). It is not a water jacket hole.

ok. I would brush it, lube the bolt and try it. if you cut new threads, which is not likely, the threads should be loose, not tight. should be able to look inside with a bright light.

 

[pdeason]

ok. I would brush it, lube the bolt and try it. if you cut new threads, which is not likely, the threads should be loose, not tight. should be able to look inside with a bright light.

I agree that I probably did not cut new threads but I may have raised a bur that is keeping the bolt from going any further. I'm not really sure what kind of wire drill tool you are talking about. Are they called by another name?

 

[pdeason]

I may get a 3/8-16 thread chaser and see if I can just clean up the threads. It's worth a shot.

 

[ned pepper]

I may get a 3/8-16 thread chaser and see if I can just clean up the threads. It's worth a shot.

hardware stores have them, like a round steel brush with a stem that fits an electric drill, or use a bristle bottle brush, something that will not cut the aluminum or damage threads. my instinct says it is residues and not metal that is causing the tight fit. shine a light in it.

 

[KANE]

How are the bolts themselves? A chaser for the threads in the head... makes perfect sense... but what about the bolts?

If they are rough, you can sometimes get a cheap emery board to get down in between the threads. Or use a die. That helps too.