FORCED INDUCTION Turbos | Superchargers | Intercoolers | H2O/Meth Injection

2014 Sierra RCSB Z71 On3 Turbo

Thread Tools
 
Search this Thread
 
Old 01-20-2018, 07:06 PM
  #121  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 673
Received 3 Likes on 3 Posts
Default

Well I think the exhaust manifold threads are ****&d. Previous owner had headers or similar(removed when traded in) and this was obvious in how nice the exhaust components were. I didn't care or make much of it.

Well, they must have used aftermarket header bolts that were shorter and didn't have a proper shoulder on them. I replaced with new, comparable 10.9 hardware from Lowes and should have just gotten OEM.

All the middle bolts were loose when I went to pull the blown gasket.

When I got the OEM bolts yesterday, it was obvious I was lucky it lasted even a hundred miles before. Most of the bolts seemed to tighten nicely save for one in the middle that was a little iffy. I used two gaskets and crossed my fingers.

After running it down the street for about 10 minutes(with no exhaust leak!) I pulled back in the shop and decided to check the bolts hot. Turning in without much pressure, all three bolts in the middle just spun. SMH.

So I probably have 30 miles before it eats those gaskets. It was making 4psi right past 1000RPM and light throttle so I at least got a taste of the improvement over before but I'm pretty disgusted knowing that it's coming right back.

So options are:

1) pull it all off, helicoil the holes in the truck
2) above and take the head off
3) get another set of heads to facilitate a swap more quickly
4) #3 but with ported heads
5) There's a guy on Craigslist with a complete 6.2 DI engine out of a low-mile truck for sale.

Guess I'm going to take the night and drink about it.
Old 01-20-2018, 07:09 PM
  #122  
Launching!
 
RySmDPT14's Avatar
 
Join Date: Aug 2017
Location: Buffalo, NY
Posts: 227
Likes: 0
Received 14 Likes on 11 Posts
Default

Or tap the holes for a larger bolt and go with it. If it fails, go with other options you listed.
Old 01-20-2018, 10:25 PM
  #123  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 673
Received 3 Likes on 3 Posts
Default

Originally Posted by RySmDPT14
Or tap the holes for a larger bolt and go with it. If it fails, go with other options you listed.
That's not a bad idea. I feel like the problem then would be the holes in the gaskets. GM makes them tight. I had to grind a couple of the bolt tips to a point(the part that was already non-threaded on the tip) as any slight misalignment results in no-go. But I could drill those out too, I suppose.

Currently I'm just pissed and embarrassed that I let all this crash over $3 worth of hardware. Not my first rodeo and surely not the silliest situation I've created but right now my time is very very tight around two jobs.
Old 01-21-2018, 10:53 AM
  #124  
11 Second Club
iTrader: (13)
 
MrHorsepowerLSx's Avatar
 
Join Date: Mar 2011
Location: NJ
Posts: 850
Likes: 0
Received 30 Likes on 30 Posts
Default

I vote for the helicoil repair method.
Old 01-22-2018, 07:59 AM
  #125  
TECH Addict
iTrader: (1)
 
Choda's Avatar
 
Join Date: May 2012
Location: Buffalo NY
Posts: 2,782
Received 61 Likes on 49 Posts
Default

damn. Id say get them fixed right. If you really want to buy that other seat of heads, have a machine shop check them out and might as well replace the springs and seals.

either way = time and $$$$$$ sucks to hear man

I used arp exhaust studs when i built my motor. not sure if they are any better or worse but they were like $130 bucks LOL
Old 01-22-2018, 10:35 PM
  #126  
TECH Resident
iTrader: (1)
 
crashmymax's Avatar
 
Join Date: Sep 2010
Posts: 759
Received 21 Likes on 19 Posts
Default

Just a minor set back. Don't let it bother you. If you have the funds put a good set of performance heads on it. Might as well slide a cam in while your at it
Old 01-23-2018, 05:27 AM
  #127  
Teching In
 
big-joe's Avatar
 
Join Date: Jan 2017
Posts: 19
Received 0 Likes on 0 Posts
Default

I dont think it will be that hard to helicoil them on the truck.
Old 01-23-2018, 10:34 PM
  #128  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 673
Received 3 Likes on 3 Posts
Default

Originally Posted by big-joe
I dont think it will be that hard to helicoil them on the truck.
I know. Just a really full work schedule this week and no time to even touch it so I'm in pouty, stomp my feet mode. I'll be over it by the weekend!
Old 01-27-2018, 01:15 PM
  #129  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
Mercier's Avatar
 
Join Date: Jun 2014
Location: Baton Rouge, LA
Posts: 673
Received 3 Likes on 3 Posts
Default

Well the 6.2 is on the way. But still going to try to get out of work at a decent time today and tear it all back off for helicoils. Will certainly make it a lot easier to sell said 5.3. Or knowing me, keep and build later.

It occurs to me that GM may not have offered 6.2(L86)/6L80 as an option. Seems like the L86s all got the 8L90? Anyone around here with knowledge of that stuff? I have a lead on a 8L/tcase combo but may not be worth it(or even compatible?)


Last edited by Mercier; 01-27-2018 at 01:44 PM.
Old 01-28-2018, 11:39 AM
  #130  
Registered User
 
Jason Zajac's Avatar
 
Join Date: Nov 2017
Location: Western New York
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Mercier
Well the 6.2 is on the way. But still going to try to get out of work at a decent time today and tear it all back off for helicoils. Will certainly make it a lot easier to sell said 5.3. Or knowing me, keep and build later.

It occurs to me that GM may not have offered 6.2(L86)/6L80 as an option. Seems like the L86s all got the 8L90? Anyone around here with knowledge of that stuff? I have a lead on a 8L/tcase combo but may not be worth it(or even compatible?)

L86 not coming with the 6 spd transmission is no problem. Your engine control module and transmission control module are 2 separate pieces and your L83 controller will run the 6.2L no problem. All you need to do to start is copy & paste all the 6.2L parameters.

As far as the exhaust manifold threads either helicoil or timesert will both serve you well



All times are GMT -5. The time now is 05:22 PM.