1. My new 383 built for forced induction has about 1/2 of the head studs leaking. We put a radiator pressure gauge on it and after 10-15mins with 13-15psi I colleted about 1 quart of coolant in the oil pan!! Do you think this is just the studs leaking or is there a head gasket issue. There is no steam or signs of coolant in the cyclinder. The car runs and idles perfect other than the coolant in the oil.

2. I have drove the car for about 300miles very easy breaking it in. I never noticed coolant in the oil when I would check the oil, but I would have to replace about 1 quart or less of coolant in the radiator everytime I drove it. This is also from leaking crossover tube also.

3. What type of thread sealant should I use to make sure these studs never leak?

Thanks for the help!!

 

i used arp's sealant,a buddy of mine had a shop put togather his 355 an he had some head studs leaking an it ended up craking his head.we had lloyd elliot send it off to have it fixed and it wasnt real pricey or anything but i could do alot more damage the longer it goes on.he lost about as much coolant as you are when he drove his so i would definetly use some arp sealer(not to much though lol)and see what happens.good luck man

 

Put some bars leak in your coolant. It will stop the leak. As for the crossover tube you probably need to replace the gaskets

 

So a quart of coolant in about 15-20mins can seap around the studs and leak back into the pan??

 

That sounds like a lot. Were the heads milled before installing them? You might have to pull the heads off and take a look as crappy as that sounds. You should be able to see where it's leaking when you pull them. What gaskets? The rear cross over shouldn't be leaking. Did you put new rubber sealing washers on them when you put it all back together?

Ken R.

 

Rogue,

The heads are new out of the box Dart 180's with Cometic MLS gaskets. The shop keeps saying that the studs can leak that much, but they also pulled the valve cover off and pressurized the cooliing system before I could get there to see exactly what was going on and "Miraculously" the leak from the rear of the engine was not there.

I really hate not having the knowledge and the sapce to work on my own stuff!!

 

FYI all Dart LT1 heads have been drilled for the coolant crossover front and back. So make sure the front is sealed correctly. Also the set Darts I put on a car were not drilled far enuff on the front and back two intake bolts, I had to stack a few washers to keep from bottoming out.

 

What is it about studs that they leak and headed bolts don't?

 

i ask this in every thread about leaking studs and nobody answers, but did you make sure the studs were fully seated? the shoulder should seat in the block. sometimes "finger tight" doesnt get them down enough. i used permatex teflon thread sealant and its worked great on both bolts and so far these studs. my motor hasnt been running long on studs, maybe 2 hr run time, but no noticeable coolant loss as of yet. i also use the stop leak before cranking up to help the gaskets and everything seal up quicker. good luck

 

I built runmyta's engine and he and I worked on the motor for a full day last week, (fixing all the head stud leaks), and one thing I learned is that Right Stuff RTV works very well at sealing head studs and 3M 5200 does not.
But it turns out that the coolant is leaking from the bottom of the engine and not the heads studs now. I have the car and will pull the motor and fix it with new block or whatever is needed.
Karl Ellwein

 

I had the same issue with ARP sealant. I ended up using teflon tape and 0 leaks!