Been doing some updates on my cooling system. Finished everything up and topped off the coolant, took it for a drive. Well, I just found out that I have other cooling issues. Apparently the freeze plugs on the passenger side are leaking. With the system nut under pressure it doesn't seem so bad but put the rad cap on (16psi) and all three leak like a sieve. I haven't checked the driver side yet.

Being a big block Dart the motor will have to come out. What bothers me is that this is a fresh motor, probably no more than 2500 miles driven on it. Guess I won't know the cause of the freeze plug leaks until I get the motor out.

Put brass freeze plugs in it...... You won't have to deal with this issue again.

Use Permatex #1 the thick viscous gasket cement in the toothpaste like tube and get freeze plugs that are wide. clean the perimeter well

Are they leaking between the plug and block or are the rusted through from the back side?
Doug

Are they leaking between the plug and block or are the rusted through from the back side? I'd support the motor and drop the K-frame before I pulled the motor.
Doug

I think most core plugs (freeze plugs if you want) are available in shallow and wide. The shallow ones are just asking for trouble in my experience. And brass is probably a good idea along with some non-hardening Permatex.

Ive used the rubber sandwich type in tight spots. If you can get the old ones out without taking the engine out, the rubber ones just slide in and then you tighten the nut and it expands and seals. They have worked great on 2 different engines Ive helped family out with. There was no way I was taking the engine out of my sisters 89 buick to replace core plugs, which I wouldve had to if I chose traditional core plugs.

Never used them on a nice car though, they are a little goofy looking, but they work

I think I could pull an engine faster than dropping a k-member

Do yourself a favor and replace ALL of them while it is out. I also like to remove the block drain plugs and install petcocks so future draining of the block is easier.

They were brass

I'm kinda debating that in my own mind. Problem is it's a big block Dart. Not much room under there.

Yeah, no reason to take a chance on the driver side

Leaking between the plug and the block

Were they dry on install?
A few here will know better than me but I have always used the Indian Head Shellac on soft plugs...brass or steel...

Don't be afraid to just pull the K frame...I think its actually easier...

Mix up some alumaseal in a cup with some water, pour the mixture in there and drive it for the rest of the winter. Drop the motor out from the bottom in the spring and replace all those plugs.

I'm available to lend a hand if you decide to tackle it.

Learned the lesson on dry freeze plug installation on my last new engine. Pulled the leaking ones out (luckily just 3 in relatively easy to access locations) and used Permatex form-a-gasket 1B, the hardening type, and that solved it.

I was planning a trip up to WA state next month. May load it up and take it with me. I'll have a hoist where we can drop everything out the bottom.

Hey, thanks for the offer. I was under the car this afternoon. The only plug assessable is the center. The rear plug is blocked by the exhaust manifold. The front plug is blocked by the motor mount.

Sure, no problem. I was able to change one in the Belvedere once but it was a bear, I couldn't imagine attempting it on the Dart.