In the above pic, I am pointing at a wonky-looking bolt, which I suspect has been screwed into the coolant temp sensor hole ?



not sure what sort of manifold/header I got here, not factory, not like the SS long header on my DD, seems to be steel welded to SS ?

This is a spare '96 engine I picked up locally, had about 170k miles on it,

TPS is broken in half, got the PDC and most of the harness

 

After looking at my '96, the wonky bolt is where the temp sending goes. There should be a terminal for it on your wiring harness close to the fuel rail branch.

 

What, russiebear, said. That is the temp sensor screw hole.

And that header looks like nothing I have seen.

That freeze plug looks pretty good. Are you going to change it anyway?

 

My 96 has the same type of exhaust manifold, I figured someone had repaired it but now that I see yours is the same way I guess it came that way from the factory.

 

That could be someone's home-made manifold or one of the hundred aftermarket...it would be tough to get all the pipes to align if you were making it in your backyard...that bolt in the sender hole is more of an issue...early 96 used it for visual coolant temp...late 96 blocked it off and tapped off the t-stat sender. ...Its a pipe thread so how they got a bolt in there shows the persistence of stupidity... what year jeep are you saving this for...Its a direct fit for everything 98 and older. I see your a 96 also. If you want to keep it stock...machine shop to bore and verify block integrity is your biggest cost...crank-pistons and bearings is a couple of hundred bucks and you got a new motor that lasts almost forever for almost nothing

 

The purpose of obtaining the motor (also got trans and TX case, and many other parts) was mainly in case if any of those items in my DD fail, I can install them immediately, as they came out of a running '96

With the temp sender hole, that is a bit tricky. I know for an absolute fact the sender bulb must be fully immersed in the coolant or they are not accurate
guess I could have to epoxy a temp sender in there, as I dont know whether a helicoil or timesert could be had to repair that thread size

Is anyone aware of the coolant temp sender thread size ?

re the manifold/headers..I havent had a real close up look at factory ones, except I am almost certain there is no SS, they are all iron ?
will measure the outlet OD, its bigger than 1-3/4"

It was a pretty good deal, the fella lived less than 1hr away, prices were low, he had a couple of '96, one super well setup, the other one a spare
Divorce and legal costs had left him unable to pay the rego costs to keep them on the road, or even pay the petrol bills

He was a good honest Jeep guy but I find divorce sales to be one of the best buying opportunities for vehicles and parts, it ended up getting scrapped before I could finish picking it over

 

Before they get eaten up by a bolt...its a 1/8 pipe thread

 

well I'll be danged!..that gold thing in middle of pic is an (broken) coolant temp sensor base screwed into the sender hole in the block

as you can see, its at an angle..and I still had to relieve the lip of the rocker cover to allow it to screw into the undamaged threads.

I know for a fact this is a mongrel of a job on a '96...its jammed in under the firewall, a long socket tends to crack it (as above)..must be done one flat at a time in vehicle with open end spanner

anyway, good news is it holds fine, all that is needed is a new sender, no dollars need to be spent at this stage, as this is a spare motor for my DD, so just swap senders if ever needed

a helicoil kit for that repair is $150, about the same as I paid for the engine

it was handy having that broken old sender, out of my big box of spare OEM sensors

the white plug is for the sender to temp gauge

 

On a separate note, I noticed that not only is there a well known freeze plug in rear of head, but also one in the block

to remove the one in the rear of block, it is 100% needed to remove the flywheel