Technical crack in head of my 40 merc

so i found i have a exteral crack in the left head that is seaping a very minor amount of anti-freeze it never runs hot and was thinking of using some kind of block seal i've never used the stuff does it work? the motor runs so good i hate to open it up......Dave

 

I wouldn't use block sealer for a crack you can see externally. Lock and stitch pins or welding come to mind.

 

its just damp seems to be coming from under oil filter up toward intake , not a crack i can see just damp after its warmed it

 

try some stop leak, works for years sometimes---Do Not tear it down unless you have to...

 

Solder Seal Block Saver to the rescue, or something similar. I've seen it work many times, in fact my son's OT Nissan has been running around with a dose of it in the radiator for about a year now. That one was passing combustion gases into the coolant and over heating.

Bob

 

I do not understand the comments about "not tearing it down". It's a flathead, for goodness sake! The head comes off, is either repaired or replaced, and the head is reinstalled. Done! Aside from the coolant drain/ refill and a head gasket, nothing of consequence is disturbed.

 

Sounds like a gasket or retorque or you need some sealer on a weepy stud.

 

You said under the oil filter...there is a stud under there that is hard to reach. Get in there and tighten everything...there may be some nuts under there that were skipped at some point because they were hard to reach.

 

i know your right but i live in murphy's world(what can go wrong will) so i will try a little stop leak first if i can make it thru the summer will pull the head in the fall.......thanks for the comments guys...Dave

 

Install a new head now to avoid surprises on the road. It's not difficult.

 

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Water glass or block sealer works well of you are in Stale Sandwich and need to get home. Be sure that you flush or good before you try it antifreeze is your enemy in this case. Pepper will get you home with a busted radiator as well. Niether should be considered a permenant repair.


If you are at home and have a tool box then a real repair is probably in order.

 

The stop leak will keep you rolling until you come up with parts and or a permanent fix. With summer.. best to fix it once and for all, start with the torque and sealant options.

In my case, it recently worked well for a car not worth throwing a ton of money into.

Bob

 

let me restate for the purpose of enhanced understanding "keep it running" unless it becomes a problem...