Calibrate temp gauge...How to?

[maddzz1]

I just swapped in a cluter and my temp gauge is reading about 160. I have a 195* thermostat. I will check the temp near the temp sender,somehow. But how do i calibrate the gauge to match?

 

Also, should the oil pressure gauge be around 20 at stop and around 42 when driving?

[LocoJeeper]

When you say that you swapped clusters... are you talking about taking the "idiot light" version gauge cluster and swapping in a full analog set from an XJ?

 

If so, you will need to replace the sensor that takes those readings. If I remember correctly, its in the far right corner of the engine block (towards the firewall) on the right hand side.

 

- Ben

[BLHTAZ]

When you say that you swapped clusters... are you talking about taking the "idiot light" version gauge cluster and swapping in a full analog set from an XJ?

 

If so, you will need to replace the sensor that takes those readings. If I remember correctly, its in the far right corner of the engine block (towards the firewall) on the right hand side.

 

- Ben

Actually...the temp sender is on the left (driver side) rear of the head, but I believe he has already done that ;) .

 

I have heard that the guage can be calibrated, but I don't know how and would be interested in that as well.

 

The oil pressure sounds fine to me...possibly reading a little low, but nothing to worry about. Hell, mine stays at 28 all the time with the engine running or not :brows: :nuts: .

[mvusse]

My temp gauge usually runs around 160, with a 195 thermostat. Replaced the thermostat, no difference, so I though my gauge was bad.

 

However, in stop and go traffic on a hot day, or sitting at a rail road crossing it goes up to 210 (no fan shroud, no aux fan), and stop and go offroading on a hot day I overheated. The coolant started boiling about 1/16" into the red zone, so I figure the gauge does read correct.

 

Installed an aux fan, but still need to wire it up, and still looking for a shroud.

[HOrnbrod]

To bench calibrate the XJ/MJ temperature gauges, I use two decade boxes (one to simulate the thermister sender resistance; the other to simulate the cal. resistor on the gauge) and a 12V power supply. The factory tolerance is only ± 7.5% accuracy, and accuracy is affected by even small corrosion resistances between the sender and the gauge terminals and/or by calcification on the sender water probe itself. So even it's spot-on on the bench, there can still be accuracy problems on the vehicle. Most inaccuracy problems can be cured by making sure all wiring connectors are clean from the sender to the gauge terminals on the back of the cluster, and making sure the gauge mounting screws are tight. They seldom go bad, but don't expect them to be right on, because they are very cheaply manufactured units.

[maddzz1]

Thanks for all the replies. Mvusse, I guess i will wait and see what happens when i get stuck in traffic :popcorn: .

 

Thanks, Don. That is way to complicated for me. I will try to take the temp near the sender and see if it reads near the same as the gauge. If it is off I will just add the difference to what the gauge is saying.