Exhaust manifold replacement: what else should I do at the same time? Share some wisdom & save me some time

TimberTim

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Mar 19, 2022
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NorCal
No it's not hard at all .yes the discs, on my "91" the large ones were 2'' AND THE SMALL ONES under the Exhaust Manifold Gasket on the Head were 3/4" . Drain coolant and simply drive a flat screw driver thru the Brass freeze Plug and pry out old plug. Clean the block opening with a wire wheel and sand paper until shinny . Put a light film of RTV Sealant on the edge of the freeze plug ( this will seal any imperfection and act as a lube for installing). Gently tap the plug with a hammer until starts and it stays in the hole by its self. then place a piece of flat stock over the plug that covers all edges of the plug, our use a large socket ( upside down) that covers the whole plug and gently tap, tap, tap, the plug into the whole, Don't Bam, Bam, Bam, the plug. set plug depth to just a hair below the chamfer on the block. this should cost around $20 Bucks....Tim
oops , I posted the wrong info.... the block expansion plugs are 1 3/4 "
 
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TRevs

TRevs

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I decided to wait on the expansion plugs. Removing and reinstalling the manifolds wasn’t too hard and I really need to get the Jeep operational again.

Right now I’m installing the rest of the exhaust pipes. There are 4 separate pieces (down pipe, cat, muffler, tail pipe) that all slide together and clamp. Hopefully I can get all the pieces together…
 

T-Rex Jeepster

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Great to know!

Is throttle body cleaner ok for the entire manifold and fuel injectors? Brake cleaner?

It’s ok to reuse the injector O-rings?
I wouldn't.....Rule of thumb for me....If I'm "In There"...Go ahead and replace all perishable parts/gaskets/O-rings and avoid the infamous....
"Oh Crap" regrets...
 
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TRevs

TRevs

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I got it all back together; ended up reusing all the injector O-rings but there are no leaks, and now that I’ve had them out it won’t be too hard to replace them a little later.

Now there’s no tea-kettle whistling anymore!
 
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Stoopid Jeep

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North Idaho
I got it all back together; ended up reusing all the injector O-rings but there are no leaks, and now that I’ve had them out it won’t be too hard to replace them a little later.

Now there’s no tea-kettle whistling anymore!
My YJ had a bad exhaust manifold gasket when I got it.

Drove it for 2 days before I couldn't take it anymore and ripped it apart. I replaced the gasket and about $450 worth of other miscellaneous parts.

Wife was like "Why are you dumping money into a car you just bought 2 days ago?" 🤪

...this was the first of many bad financial decisions related to that Jeep.

Glad you got it back together 🤘
 
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T-Rex Jeepster

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Middle Tennessee
My YJ had a bad exhaust manifold gasket when I got it.

Drove it for 2 days before I couldn't take it anymore and ripped it apart. I replaced the gasket and about $450 worth of other miscellaneous parts.

Wife was like "Why are you dumping money into a car you just bought 2 days ago?" 🤪

...this was the first of many bad financial decisions related to that Jeep.

Glad you got it back together 🤘

What I've learned about Wives.......

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