Intake manifold drastically different temperatures

Stock FSJ Tech Area

candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: Intake manifold drastically different temperatures

Post by candymancan »

blueday wrote: Sun Mar 12, 2023 9:28 pm Alright so I sucked it up and pulled the pump, tstat and radiator. I did expect to see the water pump impellers rusted off as mentioned but surprised to see everything there. If got replaced anyways. More surprised the previous owner/mechanic left me a broken off wp bolt in the block (even start drilling it). I tried torch and easy out, nope. Ended up drilling larger and larger til I got what was left to come out and cleaned up block threads. PIA by the way.

I just replaced tstat last week and it looked like this. Took about 10 minutes of running water through the passages to get it to run clear. Then moved to the heater core to flush, flushed the radiator too. Pump pump back on and ran it with the water hose on the inlet (don't laugh at my setup, it worked). Took about 12 of those smaller buckets full to get to start running clear even after all the previous flushing. Anyway, buttoned and filled everything up and so far so good.

Also had a rear door handle fall off which seems fairly common. Trying to save some money I made some walls out of tape and poured some epoxy in there good as new.

Still not sure why the "coolant" was so nasty. I'm thinking they filled with just water and no antifreeze could be a reason for all the rust.

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Ryan


Whats wrong with what you did, nothing to laugh at lol? Im the one who suggested you stick a hose in there and flush the crap out if it. Then flush with distilled to get most of the hose water out. Then mix your coolant and done.

Im glad you got it clean. How are the temps looking now ? Onky thing i hate about these amc engines is how the water pump bolts also hold the timing cover on.. if youre not carefull you lose the coolant seal between the block and timing cover.. i did.. and it leaked coolant from there.. had to tighten the bolts to APE tighteness for it to stop.

I would keep that old pump as a spare in case you need something for an emergency.
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

sierrablue
Posts: 1208
Joined: Wed Nov 30, 2022 8:02 pm
Location: MN/CO

Re: Intake manifold drastically different temperatures

Post by sierrablue »

Glad you got it figured out.

Also, clearly yours needed flushed, but it's also possible that your 300°+ reading could have been coming off of the exhaust ports that go back up for the factory choke/AIR system.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

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There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.

Mopar_guy
Posts: 73
Joined: Mon Aug 01, 2022 9:13 am

Re: Intake manifold drastically different temperatures

Post by Mopar_guy »

What I see that usually causes that much rust in a cooling system is a bad head gasket or cracked head that lets exhaust gas into the cooling system. Those gasses are acidic and causes the water passages to rust so to speak. Seeing what your main issue is, I think that's your problem. To check for air bubbles in the system, you need to have the system full when cold with some in the overflow tank, start it, and as it warms up, usually right before the thermostat opens, is when you see bubbles in the overflow tank. Use a flashlight to show in there to see it better. They will continue after the thermostat opens as well. Watching in the radiator with the cap off won't show anything unless your using one of the testers made for that.
83 Cherokee Laredo

candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: Intake manifold drastically different temperatures

Post by candymancan »

Coolant doesnt last forever older stuff was only good for 3-5 years after that it loses its ability to stop corrosion completetly. Its possible it sat for a decade or no one changed the coolant for 10 years
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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