leaking arp head studs. GM Sealant tabs?

[dmaxx3500]

if your going to re-open up the eng,first wash the studs and holes out with break-kleen,then the holes should have a clean-out tap run thru them[not a thread cutting tap-as it makes the threads to big],,then use ARP sealent/lube and run studs in by hand,newer studs have an allen hole in them,they only should be put in finger tight,as torquing them in puts stress on the threads,the ARP thread sealent will stop any seeping,install the gaskets and torque down the heads in steps[say-50lbs-75lbs-then final torque from the eng spec,, ,torque nuts down 3 times total -to stretch studs,,[lube nuts and washers with ARP sealent/lube,,ARP has all this in their catalog and web site too,,studs are re-usable,[make sure head locating sleeves are in block]

 

[J.Peart]

if your going to re-open up the eng,first wash the studs and holes out with break-kleen,then the holes should have a clean-out tap run thru them[not a thread cutting tap-as it makes the threads to big],,then use ARP sealent/lube and run studs in by hand,newer studs have an allen hole in them,they only should be put in finger tight,as torquing them in puts stress on the threads,the ARP thread sealent will stop any seeping,install the gaskets and torque down the heads in steps[say-50lbs-75lbs-then final torque from the eng spec,, ,torque nuts down 3 times total -to stretch studs,,[lube nuts and washers with ARP sealent/lube,,ARP has all this in their catalog and web site too,,studs are re-usable,[make sure head locating sleeves are in block]

That is basically what i did. Didnt use arp stuff, and i did the studs a bit more than finger tight (used an allan key to tighten them up a bit, but nothing considerable). basically followed the arp instructions.

 

[dmaxx3500]

try the ARP stuff,and don't use a wire wheel to clean threads,,ive done a ton of big block chevy boat engines [they have head holes into water jackets] and this works

 

[J.Peart]

so i drained all the oil and tore then engine down to the heads this weekend.



valve covers and the cdr have nasty goo in them.





Heads seem fairly clean, but there was some gunk. The oil i drained looked normal.



pressure tested the coolant system and found this:



There were probably others seeping, but this was the obvious one.

Turbo is off and ready to ship back to Dennis for a rebuild.

got some work ahead of me, hopefully wont take me forever this time

 

[WarWagon]

Thanks for posting pics. I imagine you are extremely relived it isn't a crack elsewhere. Well, hopefully not a cracked head bolt hole.
I don't feel so bad about using red locktight anymore.

Hopefully you post results after whatever sealer you use and we can refine the instructions for use as ARP says nothing about using sealer. IMO they should!

 

[L98TPI]

I think using a brass wire wheel to get the stubborn goo out of the threads is OK, but agree steel is not a good idea. Brass so soft compared to the studs. Also the stud ends in the block should in no way be tightened (per ARP ) they need to float loose before the nuts are tightened to spread the load evenly. If you are using Permatex Black on the wet ends you have to move right along and put that head on. You can not let that stuff set up before you torque the nuts. I had one engine where one side leaked and the other not. Went back over what I did and realized I had put all the studs in, one head on and knocked off for lunch (long ) between heads. If you are using the ARP sealer read the instruction IIRC it has a longer open time.

 

[L98TPI]

Thanks for posting pics. I imagine you are extremely relived it isn't a crack elsewhere. Well, hopefully not a cracked head bolt hole. I don't feel so bad about using red locktight anymore. Hopefully you post results after whatever sealer you use and we can refine the instructions for use as ARP says nothing about using sealer. IMO they should!

Yep, ARP should be more specific. The racers are going to do what ever, but the general users need more info.

A real eye opener for me was a demo they did on Power Block TV. They failure tested ARP studs in a clamp pressure measuring fixture. They used motor oil, Detroit Diesel thread lube AKA "Peanut Butter", and ARP's new thread lube. It was amazing to see how tightening cycles (to the same torque) progressively increased clamp pressures until failure. Also it took 2-3 cycles with the oil to get the expected clamp pressure. The Peanut butter clamped at the right pressure the first time (the reason racers use it) but the pressure soared on the next couple and broke the stud the quickest. The ARP lube hit the desired clamp pressure the first time it was torqued like the Peanut butter but didn't have the clamp pressure climb till failure on repeated cycles like the others had. Nice. :agreed:

BTW DD Peanut Butter was their answer to the same problem the torque to yield (TTY) bolts try to address. First time every time correct clamp pressures on the assembly line.

 

[OrionThade]

When you put the heads back on, be sure to torque in steps. I went to 110 FT/LBS on my studs, waited for about 4 hours and verified torque on all of them and then waited for another 24 hours and verified torque one last time. The head gasket MAY compress a bit in that 24 hour period. Mine did not when I put them on the 2nd time, but the first time they did slightly.

The Turbonators' idea to use a step bit to make a seat for an O-ring is a great idea. I wish I had thought of that. I used blue RTV on all of my studs. I ran them into the block until finger snug, but loose enough to move then wiped the excess RTV off, slid the head gasket on (I ruined a head gasket by trying to get it on the studs when they were cinched down) and then cinched down the studs. Not torqued down, just seated against the block with an Allen wrench. 10K miles later no leaks. *knock knock*

 

[J.Peart]

So i got the heads out and cleaned up. and started looking at how to 0-ring the studs. ended up settling on a 112 o-ring and a 45/64's bit. before doing the heads we made up a test rig (this is because the o-rings would sit against the studs upper threads).

We used a piece of plexiglass and drilled a hole thru for the stud and then drilled a smaller hole thru the side, perpendicular to the stud hole. We then drilled both sides for o-rings and then installed the o-rings, stud and nuts. once assembled we put oil into the smaller hole and applied 90 lbs air to it. it did not leak even after drilling out both holes larger.

The heads were then drilled and installed. the bottom threads got a coating of thread sealant. the O-rings were installed and for extra safety i applied some black permatex to the underside of the washers. the studs were then torqued to 110 ft lbs.



before sealing up the motor i pressure tested cooling system. the tester was leaking at the rad connection, but i kept topping it up as i worked on other things. i go no leaks at the studs nor any water in the pan. i left it on overnight and by morning the pressure was down to 5 lbs, but still no leaks (other than the tester). in the morning my dad got the tester fixed and we tested it for about 30-45 minutes and it held perfectly.

Got everything back together last night and fired it up this morning.


Everything seemed fine, until i got home. now i pulled the intake boot and the cdr, and have noticed there is moisture there. no oil contamination is evident but there does seem to be water. It could just be moisture from inside the engine evaporating out, but im not so hopeful. i'm going to watch water levels and oil levels tomorrow, but it may be getting parked/sold this time. I cant afford to keep doing this. it is eating up my money and life.

Sorry for the long post.

 

[WarWagon]

Top rad hose gets hard how fast?
I'd give it an oil change and run it a couple days checking levels. It had a lot of water dumped in it. Lifters and other hiding spots for water.

 

[J.Peart]

Top rad hose gets hard how fast?
I'd give it an oil change and run it a couple days checking levels. It had a lot of water dumped in it. Lifters and other hiding spots for water.

The rad hose doesn't get very hard, but i do know the rad cap is failing. going to pick up a new one later today.

I'll do an oil change tonight. hopefully everything checks out.

 

[J.Peart]

looked ok for a while, but i have signs of contamination again, water level has dropped a bit and oil has some odd signs in it as well.

Time to decide on this things fate. might try to find a k3500 crew cab srw, or maybe another burb, and swap parts over or sell it as a parts package. I know i wouldn't get my money out of it, but what do you think would be a reasonable price given all the parts in this thing?

I'm tired of working on it more than driving it. It wouldn't be so bad if i could work on it during the evenings when i feel like it, but the shop i use is ~120km away and as such i can only work on it on weekends and it then becomes a chore and takes all my free time. not fun.

 

[L98TPI]

I don't remember if you tried it or not but if not throw in some of that new(ish) stop leak with the aluminum powder in the polymer base. I forget right off who makes it. It keeps fixed the porous (as best as I can figure) block or head in a LS engined car we drive nearly every day. Worth a shot? Huh?

 

[J.Peart]

I tried the GM sealant tabs last time, an there was still a bit in the system when i put it all back together. (i know its not the same as you are suggesting but i dont think i should mix the things). I could toss in another tab i suppose.

 

[L98TPI]

I emailed a guy in my car club that I remembered had a Vette that oozed coolant into its crankcase. This is what the local vette heads told him to use and it worked.

http://barsproducts.com/catalog/view/7-head-gasket-cooling-sealant-hg-1 (mfg's website)

 

[J.Peart]

I emailed a guy in my car club that I remembered had a Vette that oozed coolant into its crankcase. This is what the local vette heads told him to use and it worked.

http://barsproducts.com/catalog/view/7-head-gasket-cooling-sealant-hg-1 (mfg's website)

Thanks for the suggestion.It does sound promising. but the truck will be towed back up to dad's place tonight and i wont be touching it for at least two weeks. need to give myself some time away from it. I may try it out then and see if that stops the leaks.

 

[NVW]

If you use Bars Leak, disconnect the lines to the heater core. I wrecked a new one with it.

 

[Brooklyn Tow]

Check into something called Permagasket.....or something like that...FWIW.

Also Thermagasket.

 

[J.Peart]

Another super late update but i did eventually get this sorted. Tore the engine out again and cleaned it all the threads with painstaking care. Used genuine arp thread sealer, replace all the o rings and used some silicone on them. Finally sealed.

 

[Will L.]

Man I hope it works for you this time.
The ARP sealer is notorious for leaking. Almost every builder I have ever seen uses blue locktite, and snugs the studs into the block. Not a lot of torque, usually just a 1/4” gun runs them in and stops before hammering.