hi
im new to Jaguar but not fixing things. here is my question.
I have noticed that the electric fan runs all the time once the engine comes up to temp. you cant hear it from inside the cabin (thank god) but I noticed it the other day when my wife came up the drive. I just recently put a new water pump and thermostat in it. im quite sure I was able to get all of the air out of the system. also the temp gauge runs right in the middle.
any info would be great thanks

 

Mmmmm.

I am on a fast S Type learning curve also, now got 2 of them.

The "wife coming up the driveway" had me thinking.

Obviously she had been somewhere in the car. So, with the a/c on the fan will operate. I believe the "S" have an a/c pressure switch for this that actually works, as versus the X300 that required a loop wire modification to ensure fan operation whenever the a/c was on.

Yes, air in system may be a contribution factor, as may be a dud thermo fan switch which would be rare.

Other significantly wiser people will chime in sooner or later.

 

Did you follow bleeding procedure via JTIS? When you say the fan is always running at temp - is it running at a slow speed or hi speed?

 

no on the procedure, where can I find this? it sounded as if on high. it was very loud. i turned off the hvac system and it continued to run.
as far as bleeding the air i ran it until it came up to temp with the rad cap off. i also took off the cap on the thermostat housing and filled with fluid when it was cold and cracked it several times once it was at temp.

 

Download JTIS here on the forum.

Without following the JTIS bleeding procedure you will have trapped air somewhere in the cooling system.

There is a bleed hose right next to the master cylinder. The open radiator cap on the overflow tank is not enough to properly bleed out air from the cooling system.

And the temp gauge is basically an idiot gauge with a needle.

You will find varying temperatures (sometimes bad) and the needle will stay in the 12 O'Clock position.

Just by the fans running high all the time - your temp must be kind of high when full warm.

Download JTIS and follow the bleeding procedure - sometimes you will need to perform it 2 or 3 times to get fully purge the air out of the cooling system.

From what I remember:

cold engine: fill up coolant through thermostat housing cap - close and tighten to 8Nm (whatever the cap says) I believe this is 6.7 ft lbs torque.
start engine w/ heater on full blast.
gently open bleed screw (hose next to master cylinder) w/ a large flat blade screwdriver.
once coolant begins flowing out close the bleeder screw. (be careful closing - over tightening can cause the plastic bleeder to break causing more issues...)
let engine cool down - refill overflow tank (if necessary) and repeat the above...

BUT - like I said - double check JTIS as I haven't done this bleeding procedure in a while...

 

I have not been able to down load the manual as of yet. i have bled the system as was mentioned on the bottom of the last post and the fan is still running on high more than i feel is correct.
i also replaced the thermostat and that got me thinking. 1st i picked one up at the local parts store. it did not have the little ball valve in it but it did have a small vent hole at the top. so do i have a bad/wrong thermostat?
Or the other thing that has me thinking is, did i put the thing back in correctly? it is currently in the housing with the spring and plunger facing rearward/tword the motor. in my haste to finish the job i forgot to note how the old one came out.
i have also noticed that the short connecting hose between the thermostat housing to the large radiator hose needs replaced before it burst,s. my question on that is, the hard plastic line that bolts to the head. how dose that seal on the head? with and o-ring or a gasket.

 

May or may not be right but you'd be wise to get the manual and you'll need especially JTIS.

 

the ball valve on the thermostat needs to be in the 12 o'clock position upon reinstall in the housing. How many times did you perform the bleeding procedure? Also, the spring of the thermostat should go into the housing facing the rear of the motor (from what I remember) what kind of external temperatures are you dealing with?

 

well per your post I have the thermostat correctly, I have bleed the system 3 times just with the small hose next to the brake booster. outside temps have been anywhere from 15 to 50 f. (got to love ohio in winter). I was finely able to get the manual downloaded and I will follow that bleeding procedure and see if this helps.
just to follow up, the temp gauge never goes beyond center but someone said this gauge should not be trusted. is this correct?

 

It stays centre over a wide range so is not much use to an engineer. OBD tools show the actual value. (Later cars also have ETM but not yours.)

 

As JagV8 mentioned - hook up a scanner that shows actual coolant temperature. I have personally seen my temperature range between 195 and 209 - 210 degrees at the highest upon full warm up.

Again, the temp gauge on the dash is of no use...

The only reason why I ask about external temperatures is if it was hot (like let's say 80 - 95 deg F - then the fan running high could very well be normal indeed) - but not at the external temps you mentioned.

I'm in NJ (ext temps - 25 - 40 deg F) my fan runs on low speed at full warm up - around 198 - 203 deg F and this includes city and highway driving.

I would consider continuing the bleeding process to be 100% sure. When you open the bleeder hose - are you getting a steady stream of coolant?