orvnoob

So I pulled a complete noob move and misread my torque wrench(not digital) and overtorqued my head bolts by 20lbs. Can I back them off and torque them to the correct specs or do I need to pull the head and replace the gasket?

Thanks in advance.

tech

Have you run the engine yet ?

s346k

i predict this will reach heights rivaling the "which oil" threads. you will most likely get varying answers. i'm curious to see what cruiser says, as i know he has been there with these engines and experienced both sides.

the gasket will be fine assuming it hasn't been heat cycled. retorqueing the bolts will be a judgement call. we're going to hear all about jeeps special tty hybrid bolt for the 4.0 and its limit of 2 uses.

to be 100% safe you'd be in another $100? maybe. bolts and gasket. steel head and block i highly doubt incurred any damage. over tightening will run the risks of warping/cracking the head, block thread damage, gasket damage and or bolt damage leading to imminent failure.

honestly, if it were mine, i would run it. assuming proper tq sequence and no iffy torqueings. only reason being - ive done and witnessed much worse on several other engines with no repercussions.

orvnoob

I haven't run it yet. I think I'm going to go ahead and grab another gasket and set of bolts since I have to pull the head to get bolt 14 out anyway. I already backed the bolts off. At this point I'm just annoyed that I didn't realize this mistake until I already had the new pushrods and rocker arms installed. There will definitely be a post on what not to do when installing a new head in the near future.

dcollins3208

Gasket should be fine, bolts will need to be replaced as they are "torque to yield" bolts meaning they are stretched after one use

s346k

replacing bolts and gasket is the most fool proof solution. be sure to inspect the cyl head well around the water jacket bolt, presuming it's the thinnest area it would be the weakest and most susceptible to trouble. with all of that said i highly doubt there is any damage to any part involved.

to my knowledge the 4.0 bolts are not true torque to yield bolts. i recall reading in the fsm that they can be used twice. true tty bolts require a tq value and then x-degree turn on top of that.

cruiser54

Run it.

orvnoob

Thanks, everyone, for the advice. I ended up backing the bolts out and replacing them and the gasket. After much wanting to just quit and tow it to the shop, it's done and running well. I do have two engine codes popping now though: P0122 for the TPS/APP and P0456 for an evap leak. Tried moving the harnesses to take care of the P0122 and that did nothing. Any thoughts?

DFlintstone

I'd likely just run it. Pretty unlikely one will break warmed up. Big difference though, mine or for someone else? I'd rather spend whatever $ it takes to make my work right over being the dope that provided something that let someone down.