Newbie
Well looks like I need to start tracking down my cooling problems. The PO has replaced the entire cooling system including the HD radiator and I took a quick 90 mile round trip and this is what was happening on the way home. the temp was 93 out.
and yes i need to clean her....
and yes i need to clean her....
BlueRidgeMark
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Nov 4, 2025
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Hmmm. That ain't fun. Do you know if he replaced the water pump?
Newbie
He says water pump, radiator, thermostat, clutch fan was all replaced at the same time. Looks like I am about to start swapping parts. Time to roll the dice.
LOL
LOL
CF Veteran
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Factory dash gauges are "rigged" to point where the designers/engineers want them to point. As long as coolant temps r within predetermined parameters set by said designers/engineers, coolant temps r "normal".
One of those parameters is 160F.....when 160F coolant temp is reached within X amount of time after cold engine start-up, a normal warm-up cycle is counted by the ECM. If 160 is not reached in X amount of time, a CEL is set, at least on OBD-II systems. Another one of those parameters is 218F....the temp when the ECM turns on the efan. 218 is where the designers/engineers decided decided things r getting a little toasty, but not overheating, so that's the temp they want the efan on to cool things down a little.
Think about it this way.....if the dash gauge fluctuated between 160 and 218 a lot, the line of XJs (and other cars as well) at the dealership, along with their furious owners, would be a mile long.........and for no reason at all because the gauge is indicating normal parameters. To prevent the long lines at dealership service departments, designers/engineers "rig" temp gauges to point in a very narrow area on the gauge as long as temps remain within "normal" parameters. Jeep/Chrysler, for what ever reason decided to print the number 210 in the middle of the gauge. Most others just have a "C" and "H" on the gauge and the need points to the middle.....just like the XJ points to the middle.
Use a scan tool (or just about any after market temp gauge) to monitor temps and one will see how temps do "cycle" up/down in various different daily and seaonal driving conditions. The "rigged" factory dash gauge just sits there in the same spot as long as things remain within normal parameters that designers/engineers have predetermined.
Arguing? "Dude's" posting some useful data.Originally Posted by djb383
The ScanGauge plugs into the ALDL under the dash and displays what the ECM is seeing/reading.....similar to the scan tool at the dealership being plugged into the ALDL port under the dash.Factory dash gauges are "rigged" to point where the designers/engineers want them to point. As long as coolant temps r within predetermined parameters set by said designers/engineers, coolant temps r "normal".
One of those parameters is 160F.....when 160F coolant temp is reached within X amount of time after cold engine start-up, a normal warm-up cycle is counted by the ECM. If 160 is not reached in X amount of time, a CEL is set, at least on OBD-II systems. Another one of those parameters is 218F....the temp when the ECM turns on the efan. 218 is where the designers/engineers decided decided things r getting a little toasty, but not overheating, so that's the temp they want the efan on to cool things down a little.
Think about it this way.....if the dash gauge fluctuated between 160 and 218 a lot, the line of XJs (and other cars as well) at the dealership, along with their furious owners, would be a mile long.........and for no reason at all because the gauge is indicating normal parameters. To prevent the long lines at dealership service departments, designers/engineers "rig" temp gauges to point in a very narrow area on the gauge as long as temps remain within "normal" parameters. Jeep/Chrysler, for what ever reason decided to print the number 210 in the middle of the gauge. Most others just have a "C" and "H" on the gauge and the need points to the middle.....just like the XJ points to the middle.
Use a scan tool (or just about any after market temp gauge) to monitor temps and one will see how temps do "cycle" up/down in various different daily and seaonal driving conditions. The "rigged" factory dash gauge just sits there in the same spot as long as things remain within normal parameters that designers/engineers have predetermined.
CF Veteran
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Right where mine runs. Must of made our sending units on the same day.Originally Posted by s346k
omg mine runs between 210 and the first hash to the left.
CF Veteran
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LOL
Have any idea what he meant by "HD radiator"?Originally Posted by clambersky
He says water pump, radiator, thermostat, clutch fan was all replaced at the same time. Looks like I am about to start swapping parts. Time to roll the dice. LOL
BlueRidgeMark
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Nov 4, 2025
- Join DateMay 2012
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Quote:
Originally Posted by EZEARL
Have any idea what he meant by "HD radiator"?
Oh, good catch. All radiators are not created equal. Maybe he got sold a bill of goods on a "heavy duty" radiator and it really isn't getting the job done.
CF Veteran
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Originally Posted by s346k
omg mine runs between 210 and the first hash to the left.
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Something tells me that even though neither of u reach 210, u r probably not doomed.Originally Posted by EZEARL
Right where mine runs. Must of made our sending units on the same day.
FWIW, here's a really cheap digital gauge from Trail Tech that would eliminate guessing which hash mark is what temp.
The sending unit would mount in the 3/4" heater hose close to the stat cover.http://www.trailtech.net/digital-gau...rature/722-eh1
Since u both have OBD-II XJs, the ScanGauge is really neat, plugs in under the dash and move it from one OBD-II vehicle to the next.
Newbie
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I think he was talking about the factory radiator for the tow package. I am not sure.Originally Posted by EZEARL
Maybe just me but I get a little suspicious when a seller starts talking about HD this and HD that.
Think my first step is the swap out the thermostat and water pump.
CF Veteran
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and yes i need to clean her....
Before going too far replacing stuff, try verifying what the gauge displays (222.5) is correct. Replacing all kinds of cooling system components won't do much good if the factory dash gauge is wacked. Then go from there.Originally Posted by clambersky
Well looks like I need to start tracking down my cooling problems. The PO has replaced the entire cooling system including the HD radiator and I took a quick 90 mile round trip and this is what was happening on the way home. the temp was 93 out.and yes i need to clean her....
Quote:
I'll bite on this one...Originally Posted by djb383
TFactory dash gauges are "rigged" to point where the designers/engineers want them to point. As long as coolant temps r within predetermined parameters set by said designers/engineers, coolant temps r "normal".
In early models, the ECT gauge in the cluster is an analog unit driven directly by a thermistor. It is not rigged whatsoever.
I am not sure how models that utilize the CCD bus operate, though I suspect it's the same as I see far too much variance on my own to support the notion of manipulated behaviour.
However, to support djb383's assertion, 195-218°F can be considered the normal operating range. The fact that most XJs run around 210°F isn't actually documented and is more of a defacto standard (even the leakdown test in the FSM says "normal" without elaborating).
Fuel for the fire... bwahahaa
CF Veteran
For me at least,"between" is meaning at 210 and down to what I'm figuring is 195 which puts it just above the hash mark.
the dash gauge on mine is pretty damn accurate. I used a ir temp gun on my Tstat housing and the dash and gun showed almost exactly the same.