My 93 olds bravada leaks water out the rear underneath engine when I put water in. Is this a freeze plug or cracked block

If there was no antifreeze , and the water in the block froze and expanded the not only did the freeze plugs blew, but you may have cracked your block. Freeze ports are cast in the engine block when made and the plugs for the holes are usually made of zinc alloy and pressed into the block. When the water does not have the proper mix of antifreeze, it expands and forces out the plugs to prevent block cracking. If it is real cold for extended periods of time it may not be enought room for the water to expand and it cracks the block. water on the ground and sometimes the plug that looks like a over sized bottlecap are evidence. If you attemp to start you car you will permantly damage your engine..

look for water in your oil or transmission fluid

old post.
This is really a suzuki G16 engine question
thats ok,
The G16s are used on Suzuki's and Trackers
Vitara's , Esteems, no others world wide.

I have all the photos and books on those cars.
real books and all parts lists. on them , graphics tool.
the freeze plugs (core plugs on all over.)
IN 1996 only one engine, G16b.
But all G16 blocks these are the same.
sides on all G16 base blocks.
2 left side 1 above filter, one just to rear of that, they are huge.
have to be blind to miss left side, (left means same as left car door)

the problem here is there are 2 engines in 1995, then one in 1996
the heads on both engine are NOT THE SAME>
the head is 8v and 16valves heads
and the 16v has freeze plugs in the top ,next to the cam. inside under valve cover !!!.

why not say where the leak is so we can narrow the search. or state the JOB?????????

i have photos of all parts in any G16.
there are no freeze plug in any 8valve head.
but the 16v yes !!!
the 16v head small inside plugs, if leaking turn the engine oil to milk chocolate fast and worse of driven. (just undid worst)

the blocks are the same, both engines, not pistons,
there are no front or rear engine block freeze plugs only side plugs 4 total.
and sure the right side under intake man will be hard to see. look under car right side to see em.
2 left easy to see and 2 right harder.
the right engine block has 2 freeze plugs one in easy view center , under intake man.
and one tucked behind that water manifold that can leak too.
now the last plugs
the 16valve head has a front freeze plug behind the cam cog wheel. and none on the rear of the head.
so 1 front and 3 inside, top.
My guess, G16b has 8 plugs total.
G16a has 4.

things that go POP in the night (cold night)
the rear water outlet fitting (head) does explode every time one runs this head on pure water, frozen, ask my how I know that, and what clueless girl did that,, heheheheheheheheh

If you look on the side of an engine block you will see a line of circular depressions about an inch and a half in diameter and about a quarter of an inch deep. These are actually holes in the side of the engine block which are plugged with a dish shaped metal plug called a "freeze plug" or "expansion plug". WHAT FREEZE PLUGS DO As with many things on a car, there is an "official reason" and a "REAL" reason for freeze plugs. The official reason (and the source of the name) is this: If you run just water with no antifreeze in your car's cooling system the water can freeze. When water freezes, it expands. If water freezes inside your engine block, it can expand and crack the block, destroying the motor. Freeze plugs (or expansion plugs) will "pop out" and supposedly prevent this. In reality this doesn't work all the time: I've seen MANY blocks destroyed by cracking without the freeze plugs popping out, or if they do pop out the block cracks anyway. THE REAL PURPOSE OF FREEZE PLUGS OR EXPANSION PLUGS Engines are "sand cast". A special type of sand is poured into a pair of boxes. A "die" is pressed into the sand, making an impression of the engine block to be cast. The sections of the mold are then put together and molten iron is poured in, forming the engine. This is why engines have a rough texture on most areas: this is the texture of the sand used to cast them.There have to be "cylinders" made of sand in the middle of this mold to create the cylinders of the engine block. These chunks of sand can't just "float" inside the mold: SOMETHING has to hold them in place. There are little columns of sand that connect the cylinder mold to the outer mold half. The mold for the cylinder "sits" on top of these. After the block is cast, these holes are machined smooth and a "freeze plug" or "expansion plug" is put in to plug the hole.
THE PROBLEM WITH FREEZE PLUGS OR EXPANSION PLUGS The problem with freeze plugs or expansion plugs is that they are made of very thin metal, AND THEY RUST!!! From the factory they are made of galvanized steel, and if you always run a 50/50 mix of antifreeze in your cooling system you should never have a problem. Unfortunately many people don't do this, and the freeze plugs rust through, creating a cooling system leak.When I replace freeze plugs or rebuild an engine I always use brass plugs: they only cost a tiny bit more and will not rust through. The manufacturers don't use brass plugs of course: they cost a few cents more, and they will save a penny anywhere they can: pennies add up to millions of dollars!
SIGNS OF BAD FREEZE PLUGS If you have a bad freeze plug your vehicle will leak coolant. If you have a slow cooling system leak that comes and goes, you may have a pinhole freeze plug leak. l Freeze plugs are in different places on different cars, but normally they will be down the side of the block (at least 3 of them) and in the back of the block, between the engine and the transmission. Some are fairly easy to get to, others require removing various parts off the engine, some even require removing the transmission or engine to replace! Some cylinder heads also have smaller plugs in them, often under the intake or exhaust manifold.So if you have water leaking down the side of your engine, or water leaking from the hole in the bell housing between the engine and transmission, you probably have a bad freeze plug. Sometimes the hole in the freeze plug is very small, and can periodically stop when a piece of crud from the cooling system jams in the hole.
FREEZE PLUG REPAIR If the leak is slow and small, a stop leak or block seal compound might work. I have had good luck with K&W Liquid Block Seal: it's good stuff! Of course, as with any "rig" of this sort, it might not work, might not last for long, and could clog up something else in your cooling system. The right way to fix it is to replace the freeze plug. FREEZE PLUG REPLACEMENT To remove a freeze plug, first hammer it into the block with a big screwdriver or a large punch. It won't go far into a modern engine: there isn't much room behind the plug. When it "pops through" you can easily pry it back out of the hole sideways with a pair of pliers or a screwdriver. Be careful not to scratch the surface of the hole where the plug sits, or it could leak around the circumference of the new plug.
After the plug is removed, clean the hole in the block with sandpaper to remove the corrosion and old sealant. Once again, if you don't do this the new one might leak.Normal freeze plugs are hammered in with some sealant around them. I use aviation grade Permatex sealer.
A special tool is made to install freeze plugs: the tool is available at a good auto parts store. In a pinch you can use a large socket that just barely fits inside the rim of the plug, however this can damage the new plug if you aren't careful.
If you can't get to the freeze plug to hammer it in, you have to take off whatever parts are in the way to access the plug. Sometimes it's easier to remove the engine from the car. Another option when access is limited is an expanding replacement freeze plug. These replacement plugs are made of either copper or rubber. A nut on them expands the plug against the block when tightened. These plugs can be installed in areas too tight to hammer in a regular freeze plug. I have had bad luck with the rubber type: they blow back out quite often. I have had good results with the copper type (made by Dorman).
I have not had good results with either type on Ford products: Ford for some reason makes their freeze plugs in "odd" dimensions, like 1 and 51/64 of an inch. You can get the copper type plug in 1/8 th increments, but it won't expand enough to fit the Ford size. The rubber type will SEEM to expand enough, but it will stay in for a week or so then blow out, dumping all your coolant out in a matter of seconds!!!
So on all Fords I just do whatever it takes to pound a regular style brass plug into the block.

Here are some pictures of a Ford F-150 truck freeze plug job I did.

The hard part is taking the exhaust and intake manifolds off: after that the job is easy. CAUTION! I have one issue with this freeze plug video: He uses no sealant on the new freeze plugs, and he's not using brass freeze plugs.
I always use aviation grade permatex sealant on freeze plugs. It's available at any good auto parts store.Don't use RTV silicone: I've seen freeze plugs "pop out" with silicon seal.
Freeze plugs will work when put in "dry", but they might "weep" a small amount of coolant.

The advantage of the rubber expansion plug over a regular freeze plug is they are easier to install when there is very little room to work. But either way, you have to get to the old plug to remove it. You may have to work on it from underneath the car with the car up on jackstands or blocks. If the leak is along the lower side of the engine block, it probably is a freeze plug.

Cracked block? Eh... You can try to have it welded but thats not a promising fix. I think you may have signed your jeeps death certificate. On the bright side you can pick up a used motor from a salvage for around $450. Try welding it. Its worked for me before.

there are freeze plugs on back of block,between tranny and block. there are also ones on each side of block underneath exaust manifold.

You did not mention which engine you have but only three things I can think of that will do that. You need to get underneath and check freeze plugs, head gasket and block itself (for cracks). Leaks aren't that hard to find but you need to look!

should have two on each side of block i think they are three on the very back othe 4.3 and a couple on front 8 or 9 in all

sounds to be it may be the block plug or a cracked block. how old is the engine itself?