HELP - Core Plug / Freezer Plug Leaking

[83Cherokee]

Hi All,

I am a new member of AJOR.

Recently purchased an 83 Chero SJ - and yes I am very happy with the purchase

However, she has a nasty exhaust leak due a suspected core plug / freezer plug leaking on the right side of the block!

Past owner most likely never attended to the problem as the leak over time has rusted the exhaust pipes pretty bad!(looks like Swiss cheese)

Past owner advised she is "running hot" and when I saw it was leaking coolant I thought it was a head gasket... although it seams to be coming from the core plug...

My questions are:
1) What is an easy fix for a leaking core/freezer plug?
2) Will a really bad exhaust leak make it run like a dog/hot even if its timed and carb is somewhat tuned plus a 16in themo fan running?
3) Exhaust will need to be replaced, any recommendations?

Any help will be greatly appreciated.

Cheers,

[drubie]

They are quite easy to change if you have access to them. First measure it and buy the right size (most auto parts places have them in the common sizes). Get a couple just in case you mess it up.

Next step: remove the old one. If your exhaust is swiss cheese then get it off and out of the way to improve access.

Once you can reach the freeze plug, you need to jimmy it out with something. They are press-fit into the hole so you can normally stick a screwdriver through the middle of the plug (if it's rusted out like they normally are) and just lever it out. Then smear a little Permatex Formagasket on the new one and carefully hit it into place. Generally I would just grab a block of wood and hold the plug in place and hit the wood with a hammer although you can buy a specialty tool if you're feeling saucy. Don't distort the plug (this is why you might want to buy a few if you've never done it before).

It's not a technically difficult job if you can reach the plug. If you can't (like the ones on the back of the head) you are in trouble and the motor/gearbox generally has to come out for access.

edit: My SJ used to only run hot when it was basically out of coolant. I would check/replace the thermostat, thermostat housing (they corrode), the water pump might be leaking and/or ineffective (the impellers corrode). Flush your radiator out while you have the cooling system open, some of the SJ's had a pretty hard life and half of your radiator will likely be blocked with various "mechanic in a can" solutions. A leaking exhaust would not cause overheating.

[83Cherokee]

Thank for the info Drubie.

I'm currently getting my Swiss cheese exhaust repaired.

I will attempt to fit a new welsh plug and take your advice of checking other cooling system components such as thermostat and water pump whilst there.

Did a radiator flush about a week ago (before I'd noticed the leak) and they had been running it on straight water and I didn't notice only until I added coolant.

Quick question: who do/did you use to get SJ parts?

Cheers,

[drubie]

Quick question: who do/did you use to get SJ parts?

Cheers,

bjsoffroad.com pretty much exclusively.

Normally shipping from the US is very expensive but they managed to find a few ways around that.

I did use a few wreckers here for parts but anything new it was much cheaper/easier to get it direct from bjsoffroad.

Local parts places are fine for anything newer than an XJ but have all decided to charge 3X as much for SJ parts as you can buy them overseas yourself.

[83Cherokee]

G'day

Just checked out bjsoffroad.com - comprehensive catalogue and have just added them to web favorites.

Thanks for the info, excited to get the old girl running again.

Cheers!

[drubie]

G'day

Just checked out bjsoffroad.com - comprehensive catalogue and have just added them to web favorites.

Thanks for the info, excited to get the old girl running again.

Cheers!

good luck with it. I ended up selling mine and regretted it 10 minutes later. Such a beast. The ZJ is a lot more practical though.