Hi,

I'm on the reinstall leg of a valve cover gasket replacement job on a 5vzfe. Putting the lower plenum flute pipes thingy (officially known as the 'air intake surge?') back onto the intake manifold and torquing up one of the bolts to spec, well it snapped with a hollow pop. You can guess I shat myself.

So I flung the torque wrench to reverse and unwound the bolt thinking the thing would have snapped in half and half would be stuck in the inlet manifold and a nightmare to get out .. but it wound out all in one piece and appears that the bolt simply stretched, the top half twisted a 1/8th of a turn while the bottom stayed on track and then it just warped with a crack right thru the middle of the bolt. There is a def neck in the bolt now. I may have miraculously dodged a bullet there.

So I climbed into the engine bay to check the thread in the inlet manifold and the thread looks fine (as does the bottom half of the bolt), but ... the bolt hole seems to be a bottomless straight-thru hole that disappears into darkness. There doesn't appear to be any cracking on either the plenum chamber, or the manifold.

So does anyone know if this is indeed a straight-thru hole? I was expecting to see a blanked hole.

Thanks,

I must say this is def one of those jobs that doing it second time around, it would not cause me anywhere near the grief that it has as a first timer. And def worth taking the time to unplug everything off the wiring loom (crank sensors off the front of the motor and clips that run down the passenger side to the clutch-housing) to give as much lift on it for clearance for the valve cover removal and reinstall.

 

Sorry following on from this, when I pulled the throttle body off a little bit of coolant was lost. So upon reinstall, I guess I'll need to rebleed the cooling system after top-up?

 

So this morning I pulled the bolt that is next to the one that stripped. This one torqued down with no issues. The bottom of this hole is the same deal - it is a thru hole, although with this one and the bad one in the posts above it looks more like an incomplete drill-thru like you get when drilling stock and the drill bit just starts to punch thru, but then you stop before completing the hole, ie there is a little bit of stock left on the edges of the hole. Given this one is the same, I'm guessing it's all normal.

So I've retapped the bad one, replaced the bolt and I guess we'll see how we go.

 

Got everything back together today and decided to rebleed the cooling system because the throttle body hose had been disconnected, plus left the neg terminal off the battery for a good 20 mins to reset the ECU. It started up with a bit of a stumble but after that ran straight up to 1,900 revs and left it to bleed. Took prob 15 mins until no more bubbles from the coolant.
So looks like it's all running fine and apart from the ECU reset that means I'll have a 1900rpm idle for a week or two, it's all running fine. Bit of a load off the mind