Mechanics

INSTALLING THE FREEZE PLUG

2001 Cadillac STS • 99,000 miles

Hi, I have been working on my Caddy 2001 sts for a while now. The problem was that every time I added coolant it quickly drained out from somewhere. I finally figured out the problem. I had to replace the gasket and the thermostat, as well as the lower hose on the thermostat assembly. So, I did all that put it back together and added some coolant. Then I realized it was still dripping out. That's when I noticed that the coolant was now draining out from where the freeze plug goes. It wasn't there anymore. Obviously I wasn't happy. Now I need your help. Do you know where I can find a step by step guide to fix this? Also, are there any other things that I should know about when preforming this? Thank you very much for your time.

Tommy
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Wilsontd2
June 6, 2013.




The step-by-step guide is basically "pound the old one out and pound the new one in". You can get a complete set of core plugs, (aka freeze plugs), for your specific engine at any auto parts store, or they can look up the size you need and sell you just one. Many parts stores now borrow or rent tools and they will have a kit for installing the new plug. It's just a pair of extension handles and a variety of discs. You pick the disc that matches your plug, and use the handle that gives the best access.

Clean the hole out first of any rust or scale. I like to add a little bead of gasket sealer around the new plug but I doubt that helps much. It's not necessary. If you have a straight shot at the hole you might get the new plug in with a socket that just matches the diameter of the lip. Don't insert it too deeply, and don't hit it in the center. That will deform it and shrink it causing it to leak.

Usually core plugs corrode through and don't completely fall out. You might look if there was a block heater in there. It will be hanging nearby by the cord. Sometimes the wing nut that holds them in breaks but the heater won't push out until the system builds pressure.

You can also buy rubber core plugs that tighten down with a wing nut. Those are nice for places you can't reach without removing a lot of other stuff.

Caradiodoc
Jun 6, 2013.
Thank you. But I really meant, How do I get to that spot, freeze plug, starting from scratch. Meaning, I put my engine back together then realized that that was another problem. Do you know a step by step way of what I have to take out first to get to it? I'm relyng on a friends help so I gotta be positive. Thanks.

Tommy
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Tiny
Wilsontd2
Jun 8, 2013.
Hi, So What I meant to ask is, What is a step by step way of getting to the freeze vale from the start? It looks like a very difficult process. Looks like I have to remove half of the right side of the engine. Any other way?

Tiny
Wilsontd2
Jun 8, 2013.
Nope. They're all different. Welcome to our world. Some are real easy to get to because they're right out in the open. Some require the transmission to be removed. You can't get much more difficult than that.

The closest thing to what you want is the manufacturer's service manual but even that won't give you a step-by-step procedure. They only show the engine block after everything has been removed. YOU are actually in a better position to know what to do than the rest of us because you had it apart already. The best I can suggest is if you can slip your hand in there to sneak in a rubber plug, that might be a better option. Some of them have a hex nut to tighten them that you can reach with a wrench.

Caradiodoc
Jun 8, 2013.
Hi again. You guy's have been so very helpful. Thank you, But now, when I start my 2001 caddy sts, there is little leakage from tailpipe, and now leaks from different spot. Now it seems to be leaking somewhere left of the coolant resivour and a little above, I mean north of the front of car. Any ideas? Thanks again.

Tiny
Wilsontd2
Jun 8, 2013.
I'm confused. The tail pipe and coolant reservoir are miles apart. Are you seeing leaking coolant or are you hearing and exhaust leak?

Caradiodoc
Jun 8, 2013.
All I really know is that there is a constant leak just left of the coolant resevouir leaking coolant. I think the tail pie is not true, my friend said it was after he rubbed his finger in it and maybe a litte liqiuid was on the tip but I just want to totally disregaurd that. The main thing is the leak, about a gallon a mile, I tested. I'm lost now. Are there more freeze valves on the right side or else what could it be. Also, do you know where I can find a systematic diagram of the whole engine? Thank you so much again.

Tommy

Tiny
Wilsontd2
Jun 9, 2013.
Water inside the tail pipe or dripping from it is normal. That is a byproduct of a properly working catalytic converter.

Another way to find a leak is to drain all the coolant from the reservoir, (if that's what you suspect), then inject a white, non-toxic smoke from a smoke machine. You might find one of these at an auto parts store that borrows or rents tools. Stick the hose in the reservoir through the cap, and seal it with a rag. The smoke will be under two pounds of pressure and will sneak out any leak so you can see it.

For the engine information you're looking for nothing beats a paper service manual from the manufacturer. You can order one through your local dealer or you may find one on eBay. You can also buy a subscription through one of the online services. There are links on this site to "Mitchell On Demand". "All Data" is another one. DVDs and online services are very miserable for finding stuff in a hurry but you'll get the same stuff that's in the original service manual, plus you'll find listings for related recalls and service bulletins.

Caradiodoc
Jun 9, 2013.

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