[Ethan_Pariani]

I’m rebuilding a 6.2l diesel with the banks sidewinder turbo kit, I sent the engine to a machine shop to get everything in spec and surfaced, which I double check when I got it back and it was correct. I assembled the engine and the only thing I changed were the head bolt to arp 130-4062 head studs which were torqued in. I follow the torque sequence and level for the head, then after everything was assembled I put it in the truck and added coolant which then started leaking from between the head and block on both sides. I called the machine shop and they told me to shave the guide pins, which I did to where they are just protruding, past the head gasket so they are plenty short enough not to interfere, but once I assembled everything again and added coolant it started leaking from the same spot again on both heads. please I need help

 

[DeerCreekFarm]

When you reassembled did you use new head gaskets or try to use the ones you torqued down? Also if you had the block decked and the heads resurfaced, you may need to use thicker head gaskets.

 

[Ethan_Pariani]

When you reassembled did you use new head gaskets or try to use the ones you torqued down? Also if you had the block decked and the heads resurfaced, you may need to use thicker head gaskets.

I used a new gasket everytime, and I can’t find any gaskets that are thicker. If anyone has a part number that’ll be helpful

 

[dieselolds]

9128PT felpro is the gasket needed when the decks have been machined.

Coolant leaks between the head and block certainly shouldn’t be happening.The dowel pins have been cut down so that’s definitely important.What torque values did you apply to the studs?

Was engine oil or arp moly lubricant used when you torqued it down?Both these lubricants on the upper stud threads will require a different torque value that will differ from each other.

Also did you use sealer on the lower stud threads when threaded into the block?If so what sealer did you use?

One last question….are you certain the leak is coming from between the head and block and not coming up through one of the cylinder head stud holes getting under the head stud washer and nut and then running down over the engine?

 

[Ethan_Pariani]

9128PT felpro is the gasket needed when the decks have been machined. Coolant leaks between the head and block certainly shouldn’t be happening.The dowel pins have been cut down so that’s definitely important.What torque values did you apply to the studs? Was engine oil or arp moly lubricant used when you torqued it down?Both these lubricants on the upper stud threads will require a different torque value that will differ from each other.

Thank you for the part number, the arp moly was used to torque down along with thread sealant. I snugged the stud down with a ratchet since if there was too much torque the Allen head of the stud would strip. The nuts for the studs (yes, I used the washers the goes on before the nuts) got torque in sequence and follow the level patterns in which to go

 

[Ethan_Pariani]

Thank you for the part number, the arp moly was used to torque down along with thread sealant. I snugged the stud down with a ratchet since if there was too much torque the Allen head of the stud would strip. The nuts for the studs (yes, I used the washers the goes on before the nuts) got torque in sequence and follow the level patterns in which to go

Sorry it signed me in another account, that was my reply

 

[dieselolds]

My pleasure.Glad to help anyway possible.So I guess you torqued down to 90 ft/lbs if you used the moly lube then?

If two machined surfaces are perfectly flat there’s really no reason to see a leak anyplace.

 

[Ethan_Pariani]

My pleasure.Glad to help anyway possible.So I guess you torqued down to 90 ft/lbs if you used the moly lube then?

If two machined surfaces are perfectly flat there’s really no reason to see a leak anyplace.

Yeah, that why I am throughly confused. None of it makes sense

 

[OkDually]

Sorry it signed me in another account, that was my reply

Fixed the issue and merged your posts

 

[dieselolds]

Which area is it leaking on?From the lower corners?What year is your 6.2?

 

[dieselolds]

I know the early 80s heads were known to leak coolant externally on the corners.

 

[Ethan_Pariani]

I know the early 80s heads were known to leak coolant externally on the corners.

The entire side of the head not just corners

 

[Glagulator]

Pre-cups?

 

[DeerCreekFarm]

Let me ask you this; when you torqued the ARP head studs to spec 30 then 60 then 90 using the torque pattern 1-17, did you let it sit over night and re-torque again the next day? The head studs will stretch over night so you have to re-torque again 30/60/90 same pattern.

 

[DeerCreekFarm]

Did you ever figure anything out on your HG leak?

 

[grabowski]

Let me ask you this; when you torqued the ARP head studs to spec 30 then 60 then 90 using the torque pattern 1-17, did you let it sit over night and re-torque again the next day? The head studs will stretch over night so you have to re-torque again 30/60/90 same pattern.

ARP head studs are not designed to stretch one of the reasons they are reusable compared to "stretch" aka torque to yield bolts.

I’m rebuilding a 6.2l diesel with the banks sidewinder turbo kit, I sent the engine to a machine shop to get everything in spec and surfaced, which I double check when I got it back and it was correct. I assembled the engine and the only thing I changed were the head bolt to arp 130-4062 head studs which were torqued in. I follow the torque sequence and level for the head, then after everything was assembled I put it in the truck and added coolant which then started leaking from between the head and block on both sides. I called the machine shop and they told me to shave the guide pins, which I did to where they are just protruding, past the head gasket so they are plenty short enough not to interfere, but once I assembled everything again and added coolant it started leaking from the same spot again on both heads. please I need help

Read the 10th question: The Official ARP Web Site | FAQ
"I have heard that some people have had trouble with newly installed cylinder head studs leaking water. How do I make sure I don’t have the same problem with my new ARP head studs?
Prior to installing your new head studs, it is very important that you have clean threads on both the block and the studs. First, clean up all the threads in the block with a thread-cleaning chaser, NOT a regular tap. Thread chasers are designed so that they do not remove material from threads but merely remove debris and corrosion. Make sure you go all the way to the end of the threads in the bottom of the hole. Then clean out all the holes in the block with brake or carburetor cleaner to remove all the debris. Make sure the threads on the new studs are clean. Use a liberal amount of ARP thread sealer, high temp silicone or Loctite to ensure that there will be no air pockets that can cause leaks. Then follow the ARP instructions for installing the fasteners."

 

[Wreckinball67]

I recall seeing a video that Leroy Diesel posted some time ago. I believe he was installing headstuds on a P400 motor and I recall that he said to put a sealer on the threads that protrude into the water jackets...made sense to me. Perhaps research that technique.

 

[Husker 65]

A LOT of research done over on The Truckstop on this very subject. The conclusion was that both brush on white Teflon paste and ARP's sealer will leak after install. Iirc, the testing showed that Permatex Ultrablack did the best job and held up with no leaking past the studs after tens of thousands of miles of driving on several vehicles after install in real-world conditions. This is NOT a dowel, machining or gasket issue, it is leaking past the stud threads that go into the coolant passages. You can either believe that, or waste a lot of $$$ and hours chasing wive's tales and wrong theories on why/where you're leaking from.

 

[dieselolds]

That’s why I use ultra black on pretty much everything related to things of that nature.I really don’t trust anything else to be honest.This is a job you don’t want to do a second time.

 

[Husker 65]

And here is that thread from over on The Truckstop on leaking head studs. Note the poster, WillL, was a researcher for GM on the 6.5 and drag raced them using experimental diesel fuels and radically built IPs. Also, he was in contact with both ARP and Permatex's engineers/R&D Departments while doing this research on the head stud leaking issue.

Head studs - what will stop the leak

After speaking and Emailing with Permatex: Best: Optimum Black -27037 #2: The Right Stuff (black) #3: Ultimate Black #4: Optimum Grey #5: The Right Stuff (grey) #6: Ultimate Grey There is one other possible option, but it has not been properly tested, even by Permatex for it- Seal & Lock...

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