engine and drivetrain Freeze plug weeping

[burndog]

Hey team,

 

I have a fresh engine rebuild with about 1000 miles on it and suddenly one of my freeze plugs is beginning to weep. Any suggestions on repair or the best sealant known to use to fix internally?

 

I am using the BMW blue coolant if that has any bearing on recommendation.

 

Thanks in advance!

[Hans]

I had to replace one three times. Drain the block, knock out the old plug, dry the hole, use a wire brush on a drill or rotary air unit, really clean the edge, then some sealant. I recall using grey silicone, but I've also used a permatex sealant. Use a fresh plug.

[xferboy]

You might get luck and be able to reseat it with out pulling it.  Grab the biggest socket that will fit in it, put an extension on it and give it a bit of a smack (closer to a hard tap) with a hammer, make sure you're nice and square.

 

Got lucky on a small block chev in a circle track car when we noticed one weeping and did this in the spring.  If I remember, it felt a little 'soft' on the first couple hits, then got a little more solid.

 

Of course, your mileage may vary, as this was a couple year old crate motor.

[wegweiser]

We had this happen on a freshly built 37 Chevy motor at work. Yanked out the freeze plug and replaced with another one, using Permatex "The Right Stuff". So far, so good.  I like the "tap it home a wee bit" idea though. Wish we had thought of that. Would have saved an HOUR+ of unbillable time!

[TobyB]

Brass plugs and Permatex ultra black sealant are the 'oh, crap, the first one didn't take' method I use... when a steel one starts to leak...

t

[02G]

I second TobyB's suggestion, and make sure to hit the edge of the freeze plug all round with an appropriate size drift. I think it's a 36mm OD.

Never tap it in the centre when fitting it. Sure fire way to doing it over again.

[Arizona02]

Try  Bars Leak  product  Stop Leak Tablets. Cadillac cars with aluminum engines aka Northstar roll out of the factory with tablets in the cooling system. Found this out when doing  maintenance on a Cadillac, factory  repair manual states to add tablets with new coolant.