ARP head studs and building coolant pressure

Fishouse

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Jan 6, 2022
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2 years ago I had the top end of my motor completely rebuilt with ARP head studs new head gasket, fully deleted with a mild EFI live tune. Fast forward to now 2 years later and 64000 miles and im building pressure that is going into the overflow side. What could be causing this did I blow my head gasket again or is it something else please help. Truck is a 2015 LML with 284,000 miles runs flawlessly but this dang coolant issue needs to be sorted out.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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2 years ago I had the top end of my motor completely rebuilt with ARP head studs new head gasket, fully deleted with a mild EFI live tune. Fast forward to now 2 years later and 64000 miles and im building pressure that is going into the overflow side. What could be causing this did I blow my head gasket again or is it something else please help. Truck is a 2015 LML with 284,000 miles runs flawlessly but this dang coolant issue needs to be sorted out.

What head gasket did they or you use?
 

Fishouse

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Jan 6, 2022
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I have looked hi and low for the paperwork but am unable to locate it, it was 2 years ago and I wanna say from memory it was a grade C or something but can't confirm it
 

ZeroGravity58

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Mar 23, 2008
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It could be a cheap gasket, maybe they didn't send the heads out to get checked, didn't torque studs right. The options are endless about why, but you prob won't find out why until you tear it apart.
 

Fishouse

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Jan 6, 2022
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Heads were sent out and checked/ cleaned, no clue if they were tightened down or torqued right but the mechanic that did it is very reputable just out of pocket at the moment. Damn... is there any other way the system can build pressure water pump failing or thermostat i think im grasping at straws at the moment
 

ZeroGravity58

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Mar 23, 2008
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Sometimes the cap goes bad and can hold pressure. They make a test that change color when they detect exhaust gas. I've never been a fan of the gm gaskets, I always use the Mahle gaskets. You could have a cracked head also. I hate to say it but a teardown is gonna be your only way to figure it out.
 

2004LB7

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Dec 15, 2010
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is it still standard practice to retorque the studs after a short bit or some heat cycling? is it possible they needed retorquing but didn't get it?
 

KyleC4

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Dec 30, 2016
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I’ve never found it in ARP instructions to re-torque the duramax heads or powerstroke heads. But it was something that was done when I did Cummins cylinder heads. Don’t know why, I think mainly because after a heat cycle I would recheck lash as well so why nut studs too. But they’re way easier to work on in that regard
 

2004LB7

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Dec 15, 2010
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I’ve never found it in ARP instructions to re-torque the duramax heads or powerstroke heads. But it was something that was done when I did Cummins cylinder heads. Don’t know why, I think mainly because after a heat cycle I would recheck lash as well so why nut studs too. But they’re way easier to work on in that regard
In the instructions this statement is at the bottom. I thought in some of their older instructions it mentioned doing it but it might have only been applicable for when their special lube wasn't used. probably not applicable in your situation

"ARP head studs do not require a retorque, however, ARP considers it to be a good practice to do a cold retorque after a few heatc ycles. Follow your head gasket manufacturer’s recommendation for whether or not a retorque is mandatory.
Any retorquing of the head fasteners should be done on a completely cool engine"
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
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I think since ARP started making their super lube a retorque is less necessary, as well as the old burnishing procedure. Cummins fanboys still swear by a hot torque like it's a religion
 

ZeroGravity58

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Mar 23, 2008
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I mean even if they said to do a retorque how many of us would actually do it? That's a lot of work to check them all again.
 

KyleC4

Tech
Dec 30, 2016
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I think since ARP started making their super lube a retorque is less necessary, as well as the old burnishing procedure. Cummins fanboys still swear by a hot torque like it's a religion
A hot torque huh?……I’d love to hear their reasoning behind that lol
 

ZeroGravity58

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Mar 23, 2008
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I was also told before that old school composite head gaskets would compress a little after a few heat cycles, reason why old school guys tell you to retorque. Newer MLS head gaskets don't. I don't know how true this is
 

Chevy1925

don't know sh!t about IFS
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I can understand when an o-ring or fire ring is done. Not when using a factory mls gasket though.