when i am driving especially on the highway, my temp gauge seats on the normal point. if i am stuck in traffic the temperature rises. when i get back in motion the temp goes to its spot. i am suspecting my fans are not working and i think its the thermostat. my questions are.
where is the Thermostat located?, can i replace it with out taking it to a shop? and do i have to put the car on stands? thanks

 

Mos, what you are describing is almost certainly the fans not working. Most likely it is the fan controller (black box on the drivers side upper corner of the fan assembly) that has given up the ghost.

As for the thermostat, you will need to remove the plastic cover from under the lip of the front bumper. THen, if you look a little bit on the driver's side, you will see a black bulge in the hose running from the radiator to the motor. That is the thermostat. You undo the 2 clamps, it pops right out. Granted, be ready for most of the coolant system to drain too. So, you may want to drain out all of the coolant using the radiator drain first (bottom passenger side of the radiator).

As for putting the car on jack stands, it would be advisable. There isn't a lot of room between the bumper and ground. So, getting it up another 6" will make a lot of difference.

If you need more info, let me know. I've done this job. Pretty straight forward.

 

so should i start with the Fan controller first before i go to the thermo? if yes what do i need to do? i feel like driving your direction right now lol

 

MOS, the quick check is to open the hood of the car with the motor cold. Now, start the car and immediately put the A/C in the manual mode and crank it down as cold as it will go and the dash fan on as high as it will go. Now, get out of the car and feel for lots of air coming from the fans. If you are getting only a little bit of air or no air at all, then you have a bad fan controller or bad fans. From there you can check the fans via a resistance check, but then, 99% of the time, it is the controller that has failed.

So it is your call.

 

i will try that on the weekend. fyi if i turn on the a/c auto/or manual when i am driving especially on the high way. the air is nice and cold. if i am driving locally with a lot of stops, it is not as cold. say if the fan controller is dead, do i have to buy the whole fan frame thing or just that controller. i am not a mechanic, but i am technically knowledgeable, lol. thanks Thermo

 

Mos, the A/C gets its cooling from the same place the engine does. So, if the motor isn't getting sufficient cooling, then your A/C isn't either.

As for what you have to buy, that will be dependent on where you buy the item(s) from. If you go through Jag, they will have you buy the whole assembly (fans and controller). A lot of wrecking yards will try to sell you the whole complex too (granted, at a lower price, but then you are getting used parts). Some other places are willing to sell you just the module. But, you will probably find that the module is going to be only slightly cheaper than buying the whole assembly.

As for installing, it isn't that tough. As I recall, if you do the whole assembly, you undo the plug on the control module, you undo 4 bolts and then the fan assembly drops out the bottom of the car. Installing is the opposite. If you can get just the controller, then you are looking at undoing 2 plugs, removing 4(?) screws and then the controllers comes off. Install is the reverse. So, if you have any mechanical ability, you can do things either way.

 

thanks Thermo, I will try to check it out tomorrow.
just for my knowledge, i thought the thermostat was responsible for triggering the fans to run or stop. what does the thermostat do?

 

Mos, there are 2 different "thermostats" in the car. There is an electronic one that simply feeds information to the ECU which then uses that information to control the fans, fuel mixture, etc. You then also have a mechanical thermostat. This is what most people think of and this is nothing more than a spring loaded valve that as it gets up in temperature, the valve starts opening up. At some point, the flow through the valve is sufficient to maintain the cooling system at a constant temperature as the cooling effect of the radiator matches the heat addition by the engine at a desired temp. If the engine starts making more heat (ie, stepping on the gas pedal harder), the temp of the coolant rises, the valve opens more, more cooling can occur in the radiator, therefore driving the temp of the engine back to where it needs to be.

 

Thermo can correct me if I'm wrong, but when I shut off the engine the cooling fans remain running for a efw seconds after so I can always tell if they are working correctly. My X (knocking firmly on wood) always runs in the normal heat range, even in traffic at 80 degrees outside. I have yet to have the gauge rise above the fraction below center setting.

 

sidewalkman, some cars will run the fans for awhile afterwards, some won't. This is where the 2 different thermostats come into play. If you have a mechanical thermostat that is running a bit on the cool side (say a few degrees low) and the electrical thermostat is reading a few degrees low (so actual temperature is higher than the indicated, therefore the computer thinks the car is running a little cool), the fans may never run when you turn off the car (as is the case with my car). But, if you have a mechanical thermostat that is running a little on the warm side and the electrical thermostat indicates a little high (actual temp is lower than what the computer thinks it is), you can get the fans to run after the car is turned off. Gotta love tolerances. Part of this also depends on how hard you are running the car right before turning it off. If you live say a block off of a major expressway and you can get to your house in no time, yes, the fans are more likely to come on than say the person that has a mile before their house where the whole drive is around 30 mph going through residential areas (gives the motor time to remove the higher heat from driving on the highway).

So, as you can see, there are a few variables that can play into whether the fans will after turning off the car. But, by putting the A/C system on max, this forces the ECM to run the fans on maximum speed, regardless of the engine temp (as indicated by the electric thermostat).

Hopefully this all makes sense.

 

Over memorial day weeken on I 95 we were stuck due to a bus crash for 3 hours in 100 degrees plus, AC cranked up traveling at well below 5mph. No heating issues. Gauge was slightly below mid way as it always is.

 

i just did the checks you suggested an definitely my fans ain't working. i noticed a silver(heat sink) thing on the top side of the fan assembly, driver's side. it is rectangle and it has spaces in it. looks like its made of aluminum. it has a sticker that says pcd temperature tested regulator. is this the fan controller?

 

Mos, that would be the unit in question.

 

I had/have the same problem, but realized that somehow I am actually a quart of coolant low. Filled it up and haven't had the problem again, but will have to check the fans.

 

can't find a brand new module that is sold separately. i think my only option is to get the whole fan assembly unit. does anyone know where i can get a brand new fan module?

 

so what I am doing is searching in google "jaguar x type fan module site:ebay.com" to find ones that haven't been purchased but the auction just ended. I am then talking to the sellers to try to buy them direct from them. Talk to the seller "tomsforeignautoparts" as he had two for sale awhile back and the auctions just ended. Until I get my new module I am just hard wiring a switch to my battery for the fans to function and I don't overheat in rush hour. Hope that helps

 

I haven't replaced my fan assembly yet, but might have to. FYI Jag dealer says a coolant hose also has to be disconnected to get the assembly out. Not sure if this is necessary or just makes it easier.

 

I looked at it, and you can move the coolant hose out of your way to get to it. It would be easier with the coolant hose all the way off, but I was able to move mine out of the way without disconnecting it and got enough room to be able to get my whole hand in there.