Blown head gasket?

[casm]

What Joe said x1000. But, adding to that:

Hey guys, took off the intake and exhaust manifold yesterday. Found that someone previously replaced the rear freeze plug with a rubber piece of junk one. And also that the second one was leaking just minor. I'm stuck trying to decide whether I should replace all five of them on the side or not.

There's a good reason for doing them all: you don't know what happened to the others.

Think of it this way: the water in the block froze, expanded, and knocked one out. OK, that one (and the one that was weeping) were obviously bad - but just because those two happen to be noticeable weak points doesn't mean that the others aren't. The other side of the coin is that freeze plugs can rot out from the inside; given the low coolant mix that was in there, there's a good chance that the others may be rusting on the backside where you can't see it and will eventually perforate and start weeping themselves.

So yes, it's definitely a case of taking care of everything while you're in there, or coming back to revisit it at a much sooner later date than would otherwise be necessary. But hey, it's a good excuse to hit the exhaust & intake manifold gaskets, too

 

[true2blue92]

Ok thanks. I wanted to change them all but then I was like well maybe I shouldn't. But I'm definitely going to. I dont have a cherry picker for the two in the rear of the engine. And kinda don't feel like dropping the trans :/ I'm lazy and run out of beer to quickly. I'm sure of it that the rear driver side one was the major source of the leak. It was replaced with that junk rubber one and it was leaking everywhere.

 

[kastein]

I would replace all of them, preferably with solid brass ones.

If you do end up needing a new motor, you can certainly pick one up for less than 500 dollars. I have good friends in this area and have never spent more than 100. If I went to the you-pull-it near me I could get one for 100, just have to pull it myself.

You can probably drop the motor out enough to get at the rear plugs by putting a board and a bottle jack under the oil pan, then unbolting the motor mounts, removing the fans and radiator, and lowering the motor slowly. Since the transmission is still connected to the vehicle, the motor will tip forward and down. Just keep a close eye on everything and make sure you don't stretch or break anything important while doing this.

 

[true2blue92]

Well I have another jeep. Same year same engine same trans identical just don't have the title. My plan is to pull that motor which already has 50,000 miles less and slowly over time rebuild it with top quality parts. Then drop it in. For now I just wanted to get this one running good for a dd.

So I pulled the radiator and whole front clip. Then removed the fan clutch, water pump, and ps pump. Pulled the exhaust/intake mani. Popped all the plugs out. Took of the driver side motor mount. And took off the valve cover.

I got new water pump, fan clutch, motor mount, valve cover gasket, 5 brass freeze plugs (the middle one is bigger), exhaust/intake gasket, 91+ radiator 3 row, fan temp sensor, thermostat, thermostat housing, and all new radiator hoses. Fixed the leak in my headers, and just gotta put everything back on tomorrow. Can't wait to see how smooth the engine is now with the new mount, the last one was completely missing the top part of the mount. And also won't have to hear that annoying exhaust leak anymore as well as I hope and really shouldnt have any more overheating problems.

 

[gradon]

Good work! I'm a believer of the stant 10244 cap as well. Fully flush out the heater core while you're in there.

 

[true2blue92]

Yeah I actually bought that cap. Then while I was doing the work to replace the plugs I decided to convert to the newer setup ha so never got a chance to use it. My uncle has a 89 as well so I'll probably just give it to him. Does anyone know the size of the freeze plug in the middle on the side it's bigger. I got 2" plugs and got to the middle one and was like WTF. So I went back to the store with the original one and the guy matched it up but when I came home it was just a tiny bit smaller and wasn't fitting right.

 

[joe_peters]

Weird, IIRC all 6 of the plugs are 2".

 

[true2blue92]

That's what I thought. My dad thinks it might have been bored out, but why would you bore that out it's not going to improve anything.

 

[casm]

That's what I thought. My dad thinks it might have been bored out, but why would you bore that out it's not going to improve anything.

If there was ever a prior replacement of the freeze plugs, it's possible that someone ground that one out (particularly if it was rusted in place), slightly enlarging the hole in the process.

Out of curiosity, this wasn't the same hole that had the rubber expansion plug in it, was it? I know you mentioned the one on the rear; just wanted to be sure I'm on the same page.

 

[true2blue92]

Correct this is the middle one the one with the rubber plug was the last one. It didn't look like any had been changed beside the last one but I'm starting to second guess that now. I'm just kinda stuck trying to figure out what to do now. I'm going to go back to car quest tomorrow and hopefully there is one slightly bigger than the last one they gave me but not to big.