Overheating bad temp gauge ?

[Tonyt22]

My 93 with a 4.7 stroker has started to run hot . I think . Have the kids suspension cyclone fan set up
After 5 min of warming up temp shows 200 but ir gun on stat housing shows 165 running a glow shift temp gauge only thing that concerns me is it was ethier so hot or dumb luck the heater mixer valve blew yesterday . Temp on the dash shot up to 240 . Jeep runs fine no milkshake clear exhaust i bypassed the heater core while I trouble shoot

 

[stickandrudder]

everytime i have a bad temp sensor probe i got wild temp swings on the gauge. Maybe try another temp sensor, return it if it's not the issue. Seems like an extreme temp swing all of a sudden.

 

[mewz99]

Bypassing the heater core might throw off your troubleshooting - I was seeing overheating while I had my heater core bypassed, my theory is that almost all the coolant flow was going through the low restriction bypass and I wasn't getting enough flow through the rad to cool it. Adding a ball valve and shutting it most of the way seemed to help a lot in my case.

I had other contributing issues also, so I might be off base, just something to keep in mind while you diagnose.

 

[algebraic429]

Bypassing the heater core might throw off your troubleshooting - I was seeing overheating while I had my heater core bypassed, my theory is that almost all the coolant flow was going through the low restriction bypass and I wasn't getting enough flow through the rad to cool it. Adding a ball valve and shutting it most of the way seemed to help a lot in my case.

I had other contributing issues also, so I might be off base, just something to keep in mind while you diagnose.

Were you seeing these higher temps across all speeds or just at idle / low speeds. Even with the orginal heater core set up i thought coolant flowed through those lines anyways. What kind of ball valve / size did you use on this? I have my heatercore bypassed and never thought about this but its a good point. that coolant running through the bypass would increase flow rate through the bypass heater lines but decrease flow through the radiator?

 

[mewz99]

Were you seeing these higher temps across all speeds or just at idle / low speeds.

I was seeing higher temps at all speeds, but significant overheating at highway speeds. Full disclosure - my torque converter wasn't locking up, which contributed a ton of heat; my transmission fluid was low, which didn't help matters; my e-fan was non-functional and my engine fan was missing the shroud...I mean, if there was a heat related issue I had it. Reducing flow through the heater core bypass seemed to help a lot but it was just one change among many (fixed all the mentioned issues and also added hood hinge spacers for airflow) and I didn't do scientific testing between each.

Even with the orginal heater core set up i thought coolant flowed through those lines anyways.

I don't know how the OG valve worked, if it turned off flow entirely or redirected it in a loop. Either way, I figure the valve and/or heater core must create some restriction compared to an open hose loop.

What kind of ball valve / size did you use on this?

I'm running a residential natural gas ball valve with 90 degree elbows and NPT to barb adapters on either end (please, laugh at me. I deserve it.). I don't recall the size, I just matched to the heater core hose.

I think it's also worth noting that different radiators could cause different results with this. If a radiator has really easy flow, this is probably much less of a factor.

 

[Evan03]

K suspension?

 

[mewz99]

K suspension?

The hood spacers? Yes