Water pump?

Shouldn't we expect higher than normal operating temperatures with a failing water pump with it not providing enough circulation? Your obd2 reading suggests the dash gauge is accurate so no apparent problem there. Yet we have under 150 degrees operating temperature.This is curious indeed. Are you sure the system is full with the proper coolant, no air in there? Are the hoses going to and from the heater hot? Are you getting heat?
 
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Have you checked the head temp? The YJs have a separate sensor for the gauge toward the back of the head and a second one on the water neck for the PCM. I've always wondered if the TJ one on the water neck would work if the water pump was out or the coolant extremely low.
 
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Flowkooler mainly uses Robert Shaw theromstats. They have a 340 model that dinensionally looks like it would work...however its 180 degrees and its out of stock.

-Mac

This is the one you need https://flowkoolerwaterpumps.com/products/robertshaw-330-160-degree-thermostat?variant=9125073354804 use the drop down to select 195. I put one in my 2000 and the temp holds very steady. Be sure NOT to drill a weep hole in it, see this thread: https://wranglertjforum.com/threads/psa-robert-shaw-thermostat.73241/
 
Shouldn't we expect higher than normal operating temperatures with a failing water pump with it not providing enough circulation? Your obd2 reading suggests the dash gauge is accurate so no apparent problem there. Yet we have under 150 degrees operating temperature.This is curious indeed. Are you sure the system is full with the proper coolant, no air in there? Are the hoses going to and from the heater hot? Are you getting heat?

Getting heat...warm trending hot but not hot hot.

Absolutely sure the air is purged. Have one of those funnels that attaches to the radiator and am squeezing both hoses. Purged all the air to the best of my knowledge.

Guessing the new thermostat is shit. Getting another one tomorrow.

-Mac
 
Are you sure you got a 195-degree Thermostat? What part # did you install? Did you install a failsafe thermostat?

Not a fail safe, Napa good brand...$2 more expensive than the cheap one. 195 printed on the button and package.

-Mac
 
This is the one you need https://flowkoolerwaterpumps.com/products/robertshaw-330-160-degree-thermostat?variant=9125073354804 use the drop down to select 195. I put one in my 2000 and the temp holds very steady. Be sure NOT to drill a weep hole in it, see this thread: https://wranglertjforum.com/threads/psa-robert-shaw-thermostat.73241/

Excellent! Ordered one two day shipping. Putting the drill bit down slowly. Good thing I bought two gaskets the last time I went to the store.

Thanks for the link!

-Mac
 
One variable at a time. Have you removed the thermostat completely to see if you get the same result?
 
FlowKooler sourced Robert Shaw 330 195 degree thermostat worked perfectly.

Shipping was prompt too...got it last night.

Pulled the thermostat housing, cleaned up everything...saw how much RTV junk was around the Napa allegedly 195 more like 160 thermostat and decided to try just a Felpro gasket. Torqued it down perfectly and it leaked profusely. Leaked more when I overtightened it by a 1/4 turn.

Pulled everything apart...dried out the gasket with a heat gun, thin schmear of Right Stuff RTV both sides...torqued...30 minutes to cure while I cursed getting the constant tension clamps back on...no leaks.

Temperature gauge shows a crack to the left of 212. 195ish on the PCM up to 197. 195.8 laser temp gauge on the block just behind the housing. Warned up on about ten minutes... ambient temperature of 44, pouring rain.

Thanks folks... thought I could get away with Napa and no...no I could not.

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-Mac
 
Whenever I've had trouble getting the t-stat to seal I've just re-used the wet gasket. Never had an issue. I will also say that for the amount of time we spend cleaning the block of gasket residue, we might as well just use RTV. It's more foolproof and ends up taking just as much time to remove.
 
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Hey all, just stumbled upon this thread. Getting slow heating code P1281 I think it is. Poor heating in the mornings & temp gauge reading low. So is Robertshaw still the thermostat of choice? Seems I can only find Motorad & brands I've never heard of. '02 TJ 4.0L
 
Hey all, just stumbled upon this thread. Getting slow heating code P1281 I think it is. Poor heating in the mornings & temp gauge reading low. So is Robertshaw still the thermostat of choice? Seems I can only find Motorad & brands I've never heard of. '02 TJ 4.0L

Robert Shaw is a wonderfully engineered, high quality T-stat.
 
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Robert Shaw is a wonderfully engineered, high quality T-stat.

Ok so today everything seemed fine & the engine light went off on the ride home. Kinda bizarre. I think I'll order one anyway, once I thought about it I think it was 2012 when I put a Stant thermostat in it.
Used to drive by a Robertshaw facility everyday back in western Pennsylvania when I was a teenager. Wonder if that one is still around. I don't get back that way much anymore.
 
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Hard to find a real Stant anymore.
I think they're all Motorad now.

I’ve held both a Robert Shaw and a Stant in my hands and there’s no comparison in quality. The crazy thing is a RS is only about $31 last time I checked, and those who order Stant’s get the Motorad crud for about $25
 
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I’ve held both a Robert Shaw and a Stant in my hands and there’s no comparison in quality. The crazy thing is a RS is only about $31 last time I checked, and those who order Stant’s get the Motorad crud for about $25

I bought one from the dodge dealer,had weep hole,new felpro gasket (dry) didn’t leak at all?reinstalled after head change(weep hole at 12.00) with a new dry felpro no leaks .i wonder why some people have terrible time getting these to seal?
 
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I bought one from the dodge dealer,had weep hole,new felpro gasket (dry) didn’t leak at all?reinstalled after head change(weep hole at 12.00) with a new dry felpro no leaks .i wonder why some people have terrible time getting these to seal?

I think maybe the housing castings are not flat. I only had trouble with an aftermarket housing. We ended up going through about four gaskets with no luck. We ended up using The Right Stuff and it sealed.
 
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