dillon410021

I went to tighten my fuel rail and one of the fuel rail bolts is is spinning. The bolt is fine, just the intake manifold holes are bad. Should I try a bigger bolt

blown 944

You will need to tap it for a larger bolt or get an insert (helicoil)

Ian Carr

yup

theedge

Get a helicoil/similar and fix it that way.

Chris White

Helicoil is the proper fix - and then convert to studs and nuts - that way the fasteners will be steel to steel for the frequently use items!
I usually convert the intake manifold to studs and nuts if it is an engine that will be serviced a lot.

95ONE

seems like overkill. I just drilled and tapped for a 8mm bolt (12mm head) extremely strong.

dougoh

this happened on my 86 951..i just went to the next size up..probably wasnt the correct way to do it but it worked fine

jmj951

Just did exactly the same thing last night to one of my fuel rail bolts that go into the intake manifold at about 4am after completing an injector reseal job, new o-rings top & bottom and new injector caps. Glad it wasn't just me. I'll be drilling and tapping to the next size up.

Tom M'Guinn

I've helicoiled nearly all of the M6 holes in my intake. They are better than new that way.

jmj951

Okay, helicoils sounds like the way to go on something that needs to be really strong. I'm not sure that's the case with the fuel rail bolts, but I'll do it anyway. Which kit would you recommend for this fuel rail bolt to the intake? M8x1.25mm?

Tom M'Guinn

The nice thing about helicoils is that they restore the original thread size, in this case M6 x 1.0. Napa carries a nice kit, as do many of the national chains these days. Be sure to use the specified drill bit size, which I believe is 1/4 inch for M6, but confirm that when you get the kit. Going over size may work but you never know what problems you may be introducing.

ibkevin

+1 on heilcoil.

Perfect, this is on "the list".

Chris White

And nothing makes your mechanic grumpier than nonstandard sized hardware....

BTW - the helicoil is actually an improvement - you will be bolting into steel threads instead of aluminum.

Nothing worse than stripping aluminum threads wheil at the track...

Chris White

Toss in some nylock nuts and you are track ready!