Freeze Plug Fix Issue

[rpowers]

Hi friends,

I've been having trouble with a rusting-out freeze plug. It's the one on the top of the head near the flywheel.

It was leaking a small bit of cooling water, so I covered it with JB Weld. That worked for a little while, then water kept seeping under the epoxy.

After several re-applications of JB weld, I gave up on that idea, and removed the epoxy to find the whole plug had rusted away to nothing.

I've cleaned the mounting are out, and have found the seating lip for the new plug.

Also, I noticed that there is a semi-triangular "flange seat" that incorporates two of the head bolts/studs. I don't see that in the panoramic view of an A-4 on the MMI website. Does anybody else have that configuration?

Also, in my spare time I fabricated a stainless steel cover plate that I may install over the new freeze plug just for further insurance (btw, it never freezes here in sunny California).

Any advice on this freeze plug issue?

Thanks!

[sastanley]

I am no expert but I think that is where on the early model heads the water came out and went over to the manifold.

Notice that I have the similar leftovers you do.

In the panoramic, it appears they've cleaned it up more and just have the freeze plug in there with no leftover 'plate' remnants. However, all their head parts still have them.

[thatch]

Fix idea

rpowers,
There are rubber, expandable freeze plugs available which might be just the ticket for this situation. Check with a "Napa" type auto parts store to see if a plug is available in the required size. They are normally used in limited access areas but should work good here also.
Tom
P.S. What part of So. Cal.?

[hanleyclifford]

freeze plug hole

I use an early head on my late model A4. You could just thread the hole for 1/2" NPT and install a plug.

[MikeB.330]

Why not order the correct expansion plug from Moyer? I just repaced the one on the rear of the head because it had started to weep a tiny bit or water. I caught it early enough that the only damage was a little bit of paint had started to lift of the head.. The plug will set you back about $16, most of which is shipping. You will have a hard time locating this plug at an auto parts store. It's not a freeze plug but rather an expansion plug.

You will have to call Moyers as I don't think it's listed in the online catalog (least I couldn't find it)

I think the plate you made will start to leak overtime anyway.

cheers
Mike

[sastanley]

good point Mike. This is one of those times where I have this little list in the back of my head of fun Moyer parts I want..When I need one little cheap part, I can justify paying to ship it because I am adding 'x' kit or 'y' upgrade at the same time.

I did that with the Oil Filter Kit from Indigo. It was almost like getting the oil kit for free!

[67c&ccorv]

What happened to your "water manifold"?

Did you convert the early model Dole system to late model cooling system?

FWIW, I like the Dole system for a non-salt water raw water cooled engine.

Cheers!

[hanleyclifford]

Please explain term "water manifold"...

[hanleyclifford]

"water manifold"

I got rid of the "T" fitting on the water jacket side plate, made up my own custom diverter for inside. I tapped out the hole in the early head for 1/2" npt, then used a hose barb for 5/8" hose to connect the head to the manifold. I returned to the Dole thermostat and external bypass with ball shut off valve, which I regard as superior to the late system with its internal (and not observable) actuation.

[MikeB.330]

Rpowers,

you should also use great care when it come time to tighten down that stainless plate. It wouldn't take much to pull the studs right out of the block.
I think (you should check this out) 35 pounds is all you want on the head bolts.

[roadnsky]

...you should also use great care when it come time to tighten down that stainless plate. It wouldn't take much to pull the studs right out of the block.
I think (you should check this out) 35 pounds is all you want on the head bolts.

Mike/All-
In a few posts, Don has made the following statement...

"The nuts on the studs have a torque value of 35 foot-pounds, but Universal informed us many years ago that their tests showed that 30 foot-pounds still had plenty of safety margin in cases where one was worried about the integrity of the lower threads of the studs."

Up to you. YMMV.
I agree with Mike though, I'd be very cautious with those studs considering the rust build up.

[rpowers]

Freeze Plug Fix

OK,

So I tried installing a brass freeze plug, but it would not seat and stay properly.

I found out seeing by the full-force stream of cooling water jetting out of the top of the engine head (we made it back to the dock).

So, I went to my plan "B", which was to use my fabricated stainless steel plate as shown in the first set of photos.

A little JB-Weld, and the head nuts to hold it, and it works great!

I also took the time to spray paint the engine head after removing all that rust, and now it looks like new! (big improvement). New plate can be seen at the bottom of the second photo.