After replacing my electric fan my car has been pegging just below the N and now more. Now that its a bit hotter...and even at night when it wasn't I get to the top or just above the N.
Nothing has changed.

After parking at night with the needle just above the N I took temp reading all over the engine bay. The stat housing, the coolant pipes, hoses, radiator, valley, heads. The hottest I could find was 167 degrees.

if the stats open at 180 degrees doesn't that mean either my gauge or temp sensor is faulty?

 

Innaccurate gauges and sending units are not unuusal on the XJSs.

Odd, too, though, that you only get a reading of 167ºF with 180ºF thermostats. You should get readings of *at least* 180F

Cheers
DD

 

This is on a 7 mile journey to and from work. I have had it in the middle between N and H before and came home to read 196 degrees.

Maybe its just not warmed up completely or my new fan is doing a good job?

 

What are you using to measure the temperature? How do you know it is accurate?

I have a IR thermometer and I checked it for accuracy at work on our blackbody temperature calibrator and it was nearly 10degC out.

Also IR thermometers need a black surface to measure accurately DO NOT measure on a metal reflective surface. The best place to measure is the black return hose to the radiator. The distance to spot ratio is the distance from an object to hold the thermometer for accurate measurement, it should be written on the unit or in the manual. The red dot is only a laser pointer so make sure it is in the middle of what you are trying to measure.

 

I am using an IR thermometer. As I said I was all over the engine bay with it including the hose your mentioned and other hotspots. Most of the time I am inches away, even though I haven't noticed a change in temp when drawing further away.