Head Stud Repair

[bigal]

I finally finished scraping the block installed the gaskets and installed a new head. I had removed the old head without removing the studs, which all seemed fine. Well, when torquing the new head I got all the nuts to 20 ft-lbs and when I went to torque to 30, #6 would not torque beyond 20. I double-nutted and pulled the stud which had crud on the course threads in the block. I then got a 3/8-16 threaded rod and threaded it into the block and it threads in a lot farther than the short length of threads on the old stud. I did try to torque this location with a 3/8-16 nut, but couldn't get it beyond 20 ft-lbs. I'm wondering if JB Weld will secure the stud or do I need to use the 7/16 repair kit? All the other studs allow torquing to 30 ft-lbs. Any advice would be appreciated.

[hanleyclifford]

I don't see how the JB Weld could be effective unless the head is pulled and the hole thoroughly cleaned. The real question is how many threads are left in the block. In this case I would go for the stud repair kit.

[bigal]

The repair can be made without pulling the head? How is that done?

[edwardc]

MMI sells the kit. The head is drilled, in-place, to a slightly larger hole. The block is retapped through the head for the next size up (7/16). A special repair stud, from the MMI kit, is installed. It has a larger dia 7/16 at the block end, and will just fit through the enlarged head hole.

Part number KTAS_04_446

[Marty Levenson]

consider removing the head

I went through a similar problem recently, and made a few mistakes. (See Bowen Island paint thread). To do it again I would consider removing the head to enlarge the hole for the 7/16 repair stud. Even though there is a stop included in the MM kit it is tricky seeing exactly how far to drill: it is easy to drill slightly into the block by accident.

Take extreme care with tapping. Dry fit a couple times. Take extreme care starting the repair stud into the retapped hole when it has JB Weld on it. I stripped my first one cross threading it and created a mess!

Good luck!

[bigal]

I wouldn't think that drilling a little into the block would be a problem. Were you able to get J-B Weld into the newly tapped hole or just the threads on the stud?

[bigal]

I tested the 7/16 drill on the head I removed and the 7/16 hole will does not provide enough clearance for a standard 7/16-14 tap; I had to got to 29/64 which just clears the tap. Lucky I had the old head to practice on, in the boat this is going to be a bitch. I may end up pulling the head. I see the problem with drill depth.

[Marty Levenson]

JB weld

I feel for you doing this with poor access. I had it in the garage, so good light and access.

Repair stud: I had the head off, so was able to seriously clean the hole. Final cleaning was q-tips with acetone. (read recently that alcohol pre JB Weld is not good.) After prep, and yes: JB Weld in the hole, put the head back on, hand tight on a few studs, to help align stud. Then JB Weld on stud threads. Then gently put a nut on it finger tight to keep it straight.

First time I did it I cross threaded and made a huge problem for myself.

For sure wait 24 hours or more before torqueing.

Good luck!

[bigal]

I was able to drill the clearance hole through the head and get the 7/16-14 tap in the block with the head on. I will not be able to clean the tapped hole as well as you but will do my best and secure with J-B Weld, I am waiting for the repair stud from MMI.

[Marty Levenson]

good luck

...should work okay. Did you order the kit or just a repair stud? Kit comes with detailed instructions: if you are just getting the repair stud PM your email address to me and I'll send a scan...

Marty Levenson

[bigal]

I just ordered the stud (should have included a new nut also) and I found the PDF version of the MMI instructions for this repair and have followed them pretty carefully. I believe I saved some $ by buying the tools I did not have and certainly some time. I do think the block has water trapped in the water jacket, do you know where the drain on the block is located?

[Marty Levenson]

water drain

Hey Big Al - there are two drains on the starboard side. Plugs are likely different than shown. If things are rusty and hard to remove it might be easier to detach the hose from the inlet tee at the water pump end.....

[bigal]

I got the head nuts torqued and tested it for compression which indicated 75 psi for 3 cylinders and one at 70; which should be OK for a tired engine. I can't get the thing to start and couldn't get a remote starter switch to work on that starter motor. I'll have to wait until I've got someone else there to troubleshoot it for spark or fuel. The process moves to a new step.

[bigal]

Got the A4 running and the only worrisome leak is around the long studs that secure the thermostat housing. I have re-torqued the head once and am in the process of changing oil to get rid of the water in the oil. I guess I may have to remove those studs to seal with Permatex. It is running very rough and doesn't like to idle, have to play with the timing when I get good oil in it.

[sastanley]

bigal..we are pulling for you..keep at it..sounds like you are on the right track. You must separate the water jackets from the oil passages..