Engine Freeze Plugs. What are they about?

[andrewgestautas]

Every breath you take, every move you make, replace your freeze plugs.

[lelandcarlson]

As some have already commented, these are not freeze plugs and will not protect your head and block from cracking if the coolant freezes. The correct term is welch plug and their purpose is for removing the sand in the casting process.

[bigd]

The term freeze plug or expansion plug is a misnomer. I've seen many blocks and heads crack due to the fact that someone used water rather than antifreeze or coolant in the cooling system during a deep freeze. Not once did those plugs ever pop out to relieve the expansion.
They are more appropriately called casting plugs. Why? Because the soul and only purpose for those holes were to drain the sand casting out of the block or heads when they were casted, the plugs are there to fill the holes of the cooling jacket.
If they were available, we never replaced them with brand new steel plugs but rather more expensive brass ones so that rotting would never be an issue again.

[georgekaplan]

A pinhole in a freeze plug inside the bellhousing was the cause of very slight coolant consumption. I only discovered it when I pulled the engine to put a rebuilt larger one in.

[dcanon]

AKA Welch Plug - designed in the USA in the 1900s by the Welch Motor Car Company

[RichardsAutoAc]

Great tip for the engine builder. Thank you Dave

[jeffdavis]

Dave i really apreciate your videos. Thanks for your mechanical expertice.

[AUTOMANJOE]

Dave, I saw a video of a guy bashing you. He was saying you're a money hungry this and that. That you're a scam artist and blah blah. A lot of the people in the comments were arguing it, and unfortunately, others agreed.
You pay your guys 40+ an hour. I'm at 20 an hour flat rate. If I had the opportunity to do that, man, I'd be a better mechanic who's able to take his time and put more love in it. I believe you do care.
There's no way you pay them that much without understanding what it's like to work hard and suffer. I'd move out there tomorrow to work with people like that. I love your channel and envy your shop! Thanks for all the great and honest content!

[elcubano]

In 1983, my 1979 TransAm (403 Olds) was terrible about leaking freeze plugs. I don't know what kept causing it but I sure did learn everything there was to know about "freeze plugs" back then

[russellwaterman]

I appreciate the videos there's a lot of useful information thank you for being diligent about the information you give

[chuckmackenzie]

Dave, they’re casting ‘cup’ plugs and take it from a Canadian they don’t stop the casting from freezing by ‘popping out’.

[chrissnow]

Thanks Dave please keep praying for me and my family in Jesus name brother

[merg]

Always change your radiator fluid when required and use the additive if necessary then you might not have that problem

[Thetreecutter]

The First thing we did before we even STARTED to clean the block was knock out the freeze plugs.

[jabinscepurek]

For us in the north Midwest. Those plugs are important except for. One which decades ago would replace one with a block heater to make cold winter starts easier. Back in the 70's and 80's during the winter fuels had less detergents and additives than now so moisture would be mixed in and freeze, stopping fuel flow. So to prevent problems it was best to never let your fuel tank sit overnight half full or less and every refuel pour in a bottle of HEET to get rid of moisture and keep the engine cleaner. Sometimes I would "forget" to plug in the block heater so my car would not start, just for the excuse to drive Mom or Dad's car to school instead.

[fuzzrobinson]

I would make that a must when rebuilding..

[jimbojimbo]

Dave you're fire. Keeping it real keeping it honest and I love you always pushing for having the best product because you but we all know that the big manufacturers may not make the best product but there are things that we can do to mitigate and I appreciate your sincere.

[wyliecoyote]

Dave knows what he's talking about, I found a cooling system leak on a V8 351/400 Ford engine where there was a micro pinhole in the freeze plug. I removed the old plug, polished or metal sandpaper cleaned the perimeter of the hole and tapped in a new one with a bit of silicone around the edge side of the new plug. Worked out well. Longtime ago but I think I had to remove the starter to get easy access to the plug, ease of hands movement. It was a dually F350, I think it was a 1976 model, 76 or 78....

[OceanusSeafreeze]

Were putting you on the good list of CEOs when the day comes.

[pw_m]

In the UK we call them core plugs. Have seen core plugs that have been pitted .