Engine first fire mostly successful - freeze plugs leaking

[xr4tic]

Fired up the new rebuilt engine for the first time (only took a year), good oil pressure, couple of quick throttle blips sounded good, only ran for maybe a minute.  Temp gauge never moved.

 

I was pretty stoked until I checked for leaks and realized the freeze plugs were weeping.  Every. Single. One.

 

I'm really not sure how I screwed it up?  I tapped them in from the outside edge and they were flush with the bevel in the block.  I don't remember if I put them in dry, I think I used Permatex High Tack (it's been over a year)

 

Bad batch?  These are the plugs:  https://www.fcpeuro.com/products/bmw-engine-expansion-plug-11111717939

 

I didn't replace the one in the back, covered by the trans, so hopefully dodged a bullet there.

 

Any tricks/tips to do it better?

[TobyB]

I am paranoid about those things, too.

 

What I have been taught, and do, is use a socket

that fits pretty snugly inside the plug.  Then a thin coat of 

Permatex ultra black on the perimeter,

then tap it in so that the rim sits about

1/16" below the casting surface.

 

I think by tapping on the rim, you've mushroomed it,

and made gaps for leaks.

 

They're pretty easy to change- drill a small hole, then run a big

self- tapping fastener in.  And pull.  You can use a claw hammer

for the full- Bubba effect.  It does work, tho.

 

hth

 

t

 

[dlacey]

Fit them in the same way a corpulent Bavarian  on the production line would have done in the 1970s: generous sealant goop & whack them hard with a big hammer, deforming/spreading them slightly...then stand back & swig a beer.

[xr4tic]

Thanks, maybe beer was the missing ingredient.  That and Permatex.

 

They're easy to change....once the manifolds have been removed.

 

 

[2002Scoob]

It's the rear-freeze plug that should be your worry, if it's weeping too. Then ya gotta pull the trans. 

 

Edit: re-read your post in that you didn't replace the rear. Why not? I'd do it for the additional insurance. Mine were pretty corroded, the rear-plug especially.  

 

I scotch-brite'd the holes to remove any corrosion, and then gave a light smearing of Permatex before carefully driving 'em in with a socket and a rubber mallet. I then wiped any excess sealant off the plug block and let cure for 30 min. Afterwards, for extra insurance and aesthetic value I did an extra small bead, and wiped it into a nice radius of sealant between the block/plug.

 

This was pre-aesthetic bead- but you get the idea.

 

No leaks! 

 

 

 

 

 

 

Edited August 26, 2019 by 2002Scoob

[Hans]

An important step as mentioned is to scotchbrite the hole.  Then asToby says, use a big socket. I had to redo one three times.

[xr4tic]

3 hours ago, 2002Scoob said:

It's the rear-freeze plug that should be your worry, if it's weeping too. Then ya gotta pull the trans. 

 

Edit: re-read your post in that you didn't replace the rear. Why not? I'd do it for the additional insurance. Mine were pretty corroded, the rear-plug especially.  

 

I probably should have done it, but given my success rate on the other 7, I'm kind of glad I didn't.