I ended up stripping one of the front bolts on my intake manifold during the final torque and I'm looking for some help in identifying which helicoil set I need for the repair. Would also welcome any thoughts/advice to my approach. First, is the helicoil the best method for this or is there something else I should be considering? The bolt hole is accessible so I'm planning to drill and tap without removing the manifold as there appears to be enough room to do so without also cutting the manifold. I believe the helicoil kit comes with the standard coils but I did see a video where they were being used on a stripped head bolt and a longer coil was used in that application. Thoughts on whether or not the standard size would be sufficient for the intake manifold bolt? Thanks!

 

Which bolt is it? It makes a difference relative to the water jackets in the head versus the intake ports.

 

It's the driver side front. One of the longer bolts on the manifold. Here's a pic of it.

 

How did this happen? Over torque?

 

No. Was bringing it to the final torque spec and it just lost tension. All of the other bolts were fine. From other posts I've read it seems not all that uncommon.

 

28 foot lbs? whats the torque supposed to be? Probably had coolant in the hole. That bolt is also supposed to be longer than the rest.

 

Per the AtlanticBritish video I've been using, the final torque on those bolts is 38 fl.lbs. And, yes, it is the longer bolt. It is what it is at this point. Hoping to get some feedback on the fix. Helicoil or some other method. If helicoil, what size kit matches the stock bolt? Thanks!

 

That bolt hole is next to the coolant port but looks low risk to drill through. If you truly pulled all the threads out you should be able to just drill it to correct diameter for the helicoil and tap it, although I am not sure you will have clearance to do that with the manifold installed. You might want to measure the id of the manifold hold and compare with the od of the correct tap size for helicoils vs timeserts.

 

Thanks Extinct. It's the correct sizing I'm trying to figure out at this point. I've searched for the specs on the bolt but haven't had any luck find that. I assume that's what I need to select the correct helicoil kit. Any thoughts on the bolt size?

 

Just take it to your local hardware store (since you obviously don't have a tap and die set to check with). Most of the bolts on the engine are imperial thread, going off memory I would say that one is about 5/16, but I would not trust my memory.