My car as soon as you drive it gets to the N right away and goes just a little bit after the N.

The mechanic told me the auxiliary fan is not working but did not mention that it would affect the cooling system.

I don't know anything about cars. I have an xjs 1996.

Is the auxiliary fan the reason why my car is overheating?

 

The aux fan is important and should be fixed but if the engine goes from cold to above the "N" in literally one minute, there's something else going on.

Will it keep climbing if you keep driving?

Cheers
DD

 

You might very well need a new radiator core since your engine temperature climbs that rapidly. If yours tests bad then you might as well have them replace the heater core at the same time. When I had mine done on my XJ-SC I had both cores replaced as well as the hoses at the same time. The last thing I need going out on my V12 is the cooling system. As for the aux fan perhaps the sending unit that controls it is malfunctioning.

 

I drive the car everyday for about 15 to 30 minutes. The car gets to the N in about 5 minutes in the morning. When I go back home after the car has been parked for hours in the garage the car in one minute gets to right above the N. I have not been driven for more than 40 minutes because I was afraid it would hit up. Should I test the car for more than one hour driving?

How much would it cost me to replace the radiator core?

Thank you all,

Gin

 

Have you owned the car for quite some time? If so, is this behavior different than previous? I'm assuming this is a 6 cylinder XJS.

The needle going just beyond the "N" is not necessarily overheating. It might be perfectly normal considering that it's probably pretty hot in Florida. I would drive the car a bit more and see what happens. If the needle looks like it's on a runaway trip to the "H" section of the gauge, that's bad.

Is this traffic or higway driving, by the way? Yourelectric fan is most important in city traffic.

Your '96 almost certainly has the type of temperature guage that barely moves away from "N" even over a wide range of actual coolant temperatures. Have a mechanic use a scan tool to determine the *actual* engine temperature. It won't take but two minutes for this check. Report back.

Five minutes to reach "N" after sitting overnight is normal. After shutting the engine off a lot of heat is retained for several hours, though, so it'll rise to "N" more quickly the next time. This is normal. If it went from cold to just over the "N" in one minute after sitting over night, that would be a little strange.

I wouldn't replace anything at this point. Find out the actual temperature and drive the car a bit further to see if it gets any hotter.

Has the coolant level been checked, by the way?

Cheers
DD