c4vetteontop

Was torquing the bolt on my ls6 intake manifold and on the back bolt it sounded like a snap and now the bolts is loose. I cant tighten it any more it just spins. Im not sure what it could have been. Please help i hope i didnt mess something up to bad. Car runs fun took it for a drive.
What should i do?????

SteveDoten

inch lbs, not ft lbs

I would guess you snapped the bolt and the threads are in the head

Y2Kvert4me

Sounds like you snapped the bolt.

Those bolts don't need much torque to seal up the manifold. And because they are so long, it doesn't take much effort to break them. You wouldn't be the first person to do it.

Have you tried pulling that bolt out to see if it's broken?

c4vetteontop

That didnt even cross my mind, i thought i cracked my block or something.. thanks alot guys, i was sooo scared

Blown 346

No need to worry, if the bolt is broken in the hole, just use a easy out to remove it, check the threads, if they dont look bad your good. If they lok bad just use a tap and die set to re thread them.

jovette

If you're lucky, you may be able to screw the bust bolt remains back out, once you remove the intake manifold. If you can't get to the bolt, suggest you purchase left handed drill bits, and use small bit to drill in the middle of the remaining bolt, once the bit grabs hold, it may just screw the bolt out, assuming you have the variable drill operating at a reasonably slow speed. This technique has worked for me in the past.

oldschoolvette

good luck

CertInsaneC5

If the threads are really messed up when you get it out, get a heli-coil kit at the parts store. Good Luck!

ArKay99

I was thinking that if the bolt broke above the deck, somewhere in the intake manifold, you might not be able to get the manifold out. I hope that's not the case.

vettenuts

That's probably the biggest issue.

LoneStarFRC

Hopefully since he's dealing with a C5 here, that won't be the case and he'll still have enough vertical room to lift the manifold. Now, if he was working on an F-body!

mjwright

Well I'm glad to see that I'm not the only one. What a pain. I took the liberty to DIY my oil pressure sending unit and replacing my knock sensors the other day once my oil gauge pegged at 80 psi and DIC read 129. Apparently it's a common problem and easily replaceable once you get to it... located in the little tiny alcove beyond finger reach to a normal size man without taking the intake manifold off. Well, did the process (was fairly easy BTW) and put it all back together. Did the drive around the block and then went to re-torque the intake manifold bolts. Was just about to crack open a celebration beverage when my last bolt "Popped" and that was that. The bolt comes right out. Wonderful.

I was wondering what you (c4vetteontop) ended up doing at this point since this posting and did you go ahead and do the hassle yourself?

Any experience would be helpful.

Thanks.

vettenuts

It broke at 89 lb-in? Was it the one in the back?

TEXHAWK0

These type bolts take so little torque, I don't even try to use a torque wrench. Anything less than 10 ft-lb I just snug them down with a 1/4 inch ratchet. The main objective is to tighten them all down evenly.
I would think it more likely that the threads stripped before the bolt broke. Have you tried to pull up on the bolt yet to see if the bolt failed?

mjwright

The bolt sheared off leaving about 1/4" left of threads on the shank. I wasn't putting much torque on at all but it was apparently too much. <10 ft/lbs. Well I'll be more careful next time but for now, my next task is to get the existing remains of the bolt out. Which of course involves taking off the manifold completely and then trying to unscrew the remains. If that doesn't work, it looks like i'll have to tap it out and put a thread insert in. Right?

94legaleagle

An INCH/Lb torque wrench (even Snap On brand) can be purchased on ebay for about $75.00 plus shipping - a good investment in my book, and an excellent opportunity to expand the tools in the tool box

kromberg

To convert from INCH/Lb to FT/Lb, don't I just divid by 12

Keith

94legaleagle

Yep, and Vicey-Versa, but then your Foot pound torque wrench has to be able to go that low

jedblanks

So did it really break at 89 inch-lbs? Should I not torque mine when I put my manifold back on? Don't want to break anything.

I will do them evenly and in the correct order, but should I just snug them down with a 1/4" ratchet?

What will I hear if it leaks? Rough running? Hissing?

vettenuts

The service manual is 89 in-lb with the first pass at 44 in-lb. This requires a small wrench in terms of capability. I have one that goes down to 25 in-lb and it works fine. If you don't have the proper tool, then its a guessing game.