89build66

Well, of course I’ve finally got my Xj just how I want it and now have a pin how leak at one of the freeze plugs. It towards the rear and thought about cheap fix of JB weld, but just can’t bring myself to cut corners like that.
my question is:
should I go brass freeze plugs? Any brand in particular that is recommended? Also I have read some articles on using permatex aviation gasket seal when installing so would like input on that as well. I plan on doing the plugs down the side as I do not have the tools or physical ability to pull the engine for the plugs on the back. Any suggestions and guidance will be greatly appreciated.

jpz

I had a small pin hole leak on mine a few years back. I tried the JB weld, just to get me through winter. It did not work, never stopped leaking.

I went with brass plugs I bought from Rock Auto. Removal and install was pretty straight forward. used a larger diameter punch to knock them out, then channel locks to pull them out of the block if they slipped all the in. Used a large socket that just barely fit inside the freeze plug and a hammer to install new ones.

I spent a lot of time planning and being nervous about the job, and it turned to be pretty simple. The only tricky part was the removing and installing of the manifolds.

89build66

Thank you for responding jpz, Much appreciated. I also concerned about the plugs on the back of the motor. I would like to change them all as I’m sure they are all in about the same condition after close to 31 years. Have you ever changed the rear plugs? I reading that you either pull the engine or transmission to replace the ones in the back.

awg

the back ones would be very hard to get at, there is one behind the flywheel on a spare '96 engine I have...I presume it is a coolant passage core plug ?

even though it is better to do them all, you may be fortunate to just do one and fix your immediate problem in situ without further ado.

I usually try to get them out with a small slide hammer, with a self tapper on the end, pull it out and knock a new one in, after cleaning up the core hole

I use a light coat of Loctite non-hardening sealant

jpz

I did not do any of the rear ones. I only did the ones on the side of the block, so I can't offer any advice for the rear facing plugs.

BlueRidgeMark

I haven't done the job myself, but I can't see how you could possibly get the back ones without pulling the engine. There's just not much room there.

89build66

That is most likely what I will do for now. Thank you awg.

89build66

I have read that it is also possible to drop the transmission to access the back of the engine to change them out. I actually found a video showing that process on my same year XJ. I’m weighing my options between the two. As Derek from “Vice Grip Garage” would say, “I don’t know.” Thanks for responding BlueRidgeMark.

boxburn

My experience is only with the side ones. My experience is also the Crown Automotive steel plugs went in the bin after delaying the job by a day while I waited for brass ones to arrive. The CA ones measured 2.0xx" on the smallest edge when the hole is 2.000", my brass ones were 1.99x" on the smallest edge going up to 2.00x" on the widest point. I don't remember the exact numbers but they were too big.

I would have liked to do the rear plugs too but didn't have the time to go through the extra work to access them.

89build66

Thanks you Boxburn! I am ordering the plugs today and I was going to order CA plugs. I will go with the brass. Great tip!

boxburn

It probably was a bad batch or something and I only went with the CA as I wanted to be sure I bought them the correct size, but it went wrong. The brass ones were an absolute delight to work with.

awg

I think there is 2 core plugs in the back..the one that is behind the flexplate/flywheel would not be able to be changed without removing the trans and flexplate

The one on my '96 looks perfect...maybe it is not a coolant core plug ??

89build66

I should have all of my side plugs replaced by the end of the month. That includes the leaky plug. I think after that I will wait until winter for the plugs on the back and I’m leaning more towards dropping the transmission and going that route instead of pulling the motor. I just need to be sure there will be enough access to pop the new plugs in with trans out and flex plate off. From some pictures I’ve seen and a video I watched there seems to be plenty of room.
Any recommendations on part brands for brass plugs and manifold gasket? Also on a knock sensor? My knock sensor is coming apart.
I also have to fix a snapped off exhaust manifold stud that the PO snapped off. It doesn’t leak, but since I will have everything apart I’m going to do my best to extract it.

boxburn

My manifold gasket is a CA one, no issues so far. I just bought my core plugs from a core plug seller, Core Plug International, a UK seller though. I'm sure it's easy enough to find a similar US seller.

One other tip for you, get a magnet on an extendable stick. When I removed my plugs, 2 or 3 had flakey rust on the back which dropped into the coolant passage as the plug was hit. I scooped out a small pile of rust flakes.

89build66

Another awesome tip, thank you so much boxburn! It’s a good thing I’m doing the this, almost all of the intake and exhaust manifold bolts were barely finger tight. The bottom bolts are definitely a bear to get to. I will be investing in some swivel head extensions before I reassemble. My regular swivel adapter will be to large to fit in there decent enough to get the proper torque on the bottom bolts.