btw my temp is stable at 210, up very slightly on a hot idle. when i did a new air compressor i left the shroud off a few weeks till i was sure all was well with the air. it made no difference at all so i wouldnt worry about a small leak.
many cut off the bottom so its ezer to do in/out if needed its been said here.
i see your main concern the poor oil treatment the po did.

 

Yup it is a shame, For him it was a car and heard the rumors that jeeps were reliable so he bought it and did no maintenance or preventative maintenance to it whatsoever till it broke and was fed up with it and sold it to me and bought a honda till that blew up. So she put up a good fight from 2002 till 2009. I am positive this is the first time my jeep seen tlc in a LONG time. Sadly i had to put it off around 2011 in repairs since i was infected with mrsa and had to deal with that first then my schooling situation but back to the point. I finally got back to looking over it and getting it road worthy in 2016 till now. So hearing the oil thing what should i do in the future to it to prevent any damage or atleast prolong the life of the engine? Thats why i assumed the pump was maybe clogged from the gunk still and wanted to replace it but since the bearings were mentioned has me slightly worried now. It is at 203k miles at the moment now.

 

You can pick up a good mechanical gauge for less than 20 bucks at most auto parts stores. I got a Bosch for $16 at Pep Boys on sale. It took me all of 10 minutes to remove the electrical sender, and temporarily install the mechanical gauge, fire it up and check the pressure.

Please do that before you mess with the oil pump!


As for cleaning up your sludged engine, just do regular oil changes at shorter intervals, say, 2000 miles, and make sure you change the filter every time. Use the larger Wix filter, # 51515. I buy them in cases of 12.

http://www.discountfleetsupply.com/wix51515.html




Wix makes filters for other folks, including NAPA.


https://www.napaonline.com/en/p/FIL1515


After about a year of that, your engine should be pretty clean.

 

Track record. The oil senders are not very reliable, and the temperature senders are generally reliable.

Neither is perfect, and any diagnostics in either area should include verifying the readings before replacing parts.

 

my 97 has never ran that hot. 90* with ac running it MIGHT get up to 210.

 

The Temperature Gauge is a dirty liar!

I run a scangauge constantly and one of the things I choose to display is engine temp as reported by the ECU.

Your instrument cluster's temp gauge will read mostly-accurately until 210. From 210-235 or so, it will read.....210. At about 240 it will move up a hash mark and you think you're reading 220. That's where your picture is. At 254, the temp gauge will spike to 260 and your check gauges light will come on. When the temp goes back down to 249, the check gauges light turns off and the temp gauge reports 220.

These are observed results, not guesses. Happened to me last week with a combination of a water pump bearing going bad, 97 degree temperatures, and rushhour traffic.

I suggest that anyone who wants accurate engine temp readings get an ultragauge or one of those $12 bluetooth dongles from amazon with an OBD2 application appropriate for your phone.

The instrument cluster lies to you so that you won't immediately go to a mechanic when temps get to 230 or so, even though you really ought to know when that is happening.

 

Alright i will test it when i get the chance... Wix that name is very familiar to me lol but what would the larger filters do? And yes before i changed the electric fan it never budged past that either but i am blaming the weather because when i looked at the weather the number that said feels like was 106 degrees that day. So maybe it was just extremely hot that day ill check when i am running about again since its been cooler today.

 

[QUOTE]engine temp as reported by the ECU.

where does the ecu get its info?

 

The PCM (ecu) gets its information from the Engine Coolant Temperature sensor which is installed on the thermostat housing. It interprets a voltage resistance value from the sensor which correlates to a particular temperature.

The FSM also has a nice write up on why your cabin temperature gauge can not be used for diagnostics. Because they don't even call it a temperature gauge. It is referred to as a temperature status indicator. It receives messages from the computer, not temperature values. Basically, customers got nervous when they saw the temp gauges moving around, so the gauge now has set positions that the computer commands it to go to. 210 area for "normal", then around 220 for "high", and around 260 (red zone) for critical. This is also why you see posts where people claim that the temperature jumped from 220 to the red zone instantly. Because it did.

To be clear...the temperature gauge on the dash is not what people assume it is.

 

on a 97+ there is one temp sensor, the one in the thermostat housing. That sensor is read by the PCM (I know, I said ECU, but PCM is more technically correct). The PCM then sends out the info over the CCD bus, which is where the Instrument Cluster reads from. It sends the same info to the SCI bus, which is where the OBD2 scanners pick it up.

 

That's a bit simplified based on my experience. I monitor my water temps with the aid of an OBD II dongle and, on my 2000, the gauge follows temps with relative accuracy up to the point that the aux fan kicks in at 218 degrees. I agree that there might be set positions for "high" and "critical" from comments I've read on the forums, but mine has never been higher than ~220 degrees while I've monitored it, so I have no experience with that.

It's certainly a better monitoring tool than the Ford "idiot" gauges that literally do have 3 positions: cold, normal, hot. You can at least count on the XJ to show relative temp changes in the "normal" region if it's working properly.

With that said, mine only reads as high as the OP's picture when it is shut off hot and it heat soaks. When that occurs, the aux fan kicks in immediately after starting and brings it back down to around 200 degrees.

 

Tbone289,

Good points.

Even the FSM isn't exactly clear on the entire behavior. It implies that in the normal range that it shows actual temperature, but then in the higher ranges has "preset" positions. But it wasn't completely specific about it. I suppose the key take away is that the gauge is commanded by the computer for position, and is not reading a temperature directly as many people might assume.

 

so the system still depends on the condition of that sensor huh? including obd2 port.

and its a resistor like the oil sender.

 

my sg2 reads 206 when dash gage is just under 210.
the gage needle slowly moves +/- one needle. sg2 goes to 202.
accuracy of it all depends on the temp sensor i guess.
oops i forgot my ir gun, next time

 

OP that's around 225F or so on my Jeep. I'm trying to solve my issue as well. Only thing left to do on my set up is a new radiator.

I use a OBD2 dongle from Amazon and OBD Fusion App.

BTW my Jeep used to be rock solid at 210F hash mark. Even for prolonged idle times in the TX heat.