leaky freeze plug.......... ?

[IMNCARN82]

 drivers side,right under the motor mount.   not real bad,but now what?  can I still drive it?  Now the real questions begin...  I've been planning a re-build clean-up anyway.  This is a date correct 73' 340 block. I'ts a factory correct block too....030 over.  should i get a different motor,save this one ? I think because it's a real 340 'cuda...I should find a 340 to put back in it.  I'd like 400 hp. Probably EFI. X heads? I have TTI's,and soon a Kiesler 5 speed.3:91's. I drive alot! and pretty hard. I will continue to modify the suspension,brakes in the P-T/G direction.  What should I do ?       besides work more...    






 








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[gomopar440]

First off, I wouldn't drive it till it's fixed. The fact it's leaking now just means that when you go for a drive, and you are at the farthest distance from your garage, is when it will fail completely and leave you stranded. 

It shouldn't be too hard to perform a quick fix now even if you plan on rebuilding it soon. Better to avoid the problem before it REALLY becomes a problem.

Before you work on it be sure to drain the antifreeze first. You might be able to get by with unbolting the engine mount on the side with the leak. Then jack the engine up a little to lean it over some and remove the mount completely. You should be able to get to the freeze plug enough to knock the bad one out by carefully (so you don't knock it completely inside the block) tapping on one side with a flat screwdriver and a hammer (might need to use a stubby hammer depending on space available) to get the plug to rotate in the block until you can grab the edge of the plug with some pliers and pull it out. You'll either need a replacement freeze plug or one of those expandable plugs (last resort). The expandable ones are just two big washers with some rubber sandwitched in between them and a bolt going through the middle of all of it. You just stick the plug in and tighten the bolt and the rubber squishes out the sides to seal the edges to the block. The better way though would be to just get a correct replacement plug and use a large socket to carefully tap it into the hole. some people recommend to put some sealant (RTV?) around the edge to prevent leaks but I've never done this and never had any issues with leaks. After you get the plug in, clean and dry the area around the plug. Then reinstall everything in reverse order and add some fresh antifreeze. Start it up and check for leaks. If all looks good, you should be good to go until you decide to tear into the engine later.

[6packCuda]

    well said gomopar440.

[Chryco Psycho]

this could turn into a chain , if one is bad more will go soon , you can replace th eplug but I would pull the engine & replace them all or build another engine over the winter , if you are going to build a small block why not do a 360 or 360 based stroker with more torque than what you have now ?

[IMNCARN82]

Most people say go to a 360.  More tq., more displacement. More cost effective...         It's a 340 'cuda...?   Wouldn't you put a 340 in it?  I know I have to pull it.It needs a clean up bad. I'm not sure what to do. When it's all said and done,I wouldn't care about the money.  340?   360?       

[Rare_T_A]

If you already have a 340 in it why not just rebuild that one? I agree if one plug is leaking the rest cannot be far behind.

[nivvy]

Well I am mr freeze with all the problems I had from not having anti freeze in the car

All the plugs ended up going bad and i replaced them all.. the problem started with the leak coming from behind the heads then the block started leaking I replaced some of them myself and did use an RTV silicone putting them in but still had the block pulled and replaced all of them..no big deal since I had my main girdle installed!

After the shop put my motor back in they wanted me to do a burnout and I did and blew a plug right out of the block.... does this answer any of you questions...

I used a dremel to get em out and put them back in with a hammer and the correct size socket to pound em in cause they are a *****.... 

[ntstlgl1970]

this could turn into a chain , if one is bad more will go soon , you can replace th eplug but I would pull the engine & replace them all or build another engine over the winter...

w/CP on the freeze plugs. also, Dorman makes a brass/copper expandable freeze plug that is a little more reliable than the rubber ones...

[IMNCARN82]

If you already have a 340 in it why not just rebuild that one? I agree if one plug is leaking the rest cannot be far behind.

I wuz gonna' save this one since it's date/factory correct. And find another 340 to build.  Thanks everybody for posting,I can really use the advice. 

[Aussie Challenger]

  Freeze plugs are a time bomb waiting to happen, when one starts to leak........ 
  When I replace them I always use brass plugs and use a little of GM head bolt sealer around the outside edge, never had to replace one and they don't leak. Always clean up hole in block with a piece of emery cloth to remove any rust or impurities.   

[moper]

The plugs have been covered. If one leaks, they are all suspect. And I would replace them. As far as rebuilding... If you are thinking of upgrading the brakes and otehr stuff, wh yshould what's in it matter, so long as it makes the power you want, doesnt hurt the value of the car, and looks identical? Building a 360 is nothing but good. Building a 408 stroker is a very short jump from that. Cost wise, 360/408 builds are less money. Both in initial cost, and parts costs during the build. If you want a 340, or want to keep it original looking, that's one thing. But just to say "that's original" with EFI, a Keisler setup, big brakes/wheels/tires? That doesnt really make a ton of $en$e to me.

[IMNCARN82]

The plugs have been covered. If one leaks, they are all suspect. And I would replace them. As far as rebuilding... If you are thinking of upgrading the brakes and otehr stuff, wh yshould what's in it matter, so long as it makes the power you want, doesnt hurt the value of the car, and looks identical? Building a 360 is nothing but good. Building a 408 stroker is a very short jump from that. Cost wise, 360/408 builds are less money. Both in initial cost, and parts costs during the build. If you want a 340, or want to keep it original looking, that's one thing. But just to say "that's original" with EFI, a Keisler setup, big brakes/wheels/tires? That doesnt really make a ton of $en$e to me.

408    gotta' save some cash though.