Hi,
I read a number of posts regarding no heat but I am hoping that with the symptoms I describe that someone can give me better advice as to what I should be looking at.
Two days ago the heat was fine, but yesterday no heat at all. I felt that the air coming through the vents did not match the outside temperature. Although the air blowing inside the car was not hot at all, it was not as cold as it was outside--it was neutral. If I change the vent settings, where the air is coming out matches the settings. I checked my radiator fluid is it was fine. My thermostat seems to working fine as the temperature gauge rises as usual. I haven't tried/checked anything else yet. I do have time today but am hoping to get some advise before getting into this blinded.
Thanks!
Jomo

 

You need to check the HEATER VALVE and HEATER COOLANT PUMP.
The pump has a relay so check that also.

S95_sed.pdf is the electrical guide for the 1995 X300.

 

The round cylinder part has two hoses going into it. The top one is hot and the lower one is cold. What should I check next? Are these parts the same on my 95 xjs?
Thanks,
Jomo

 

New information. The temp gauge is reading that the fluid in the coolant system has reached operating temperature but the fluid is not moving when I open up the radiator cap. How can this be? The engine is not over heating. One additional piece of information, in the last two weeks it was taking my car about two longer before the temp gauge went to its normal position. Very strange to me but hopefully not to others.

 

Jaguar AJ6/AJ16 WAXSTATS tend to fail OPEN.

You still need to check the Valve and pump.

 

I will check that tomorrow. Is the temp gauge just an idiot gauge that reads normal even if the temp is below normal. I know that the oil light is like that? If it is like that then maybe the thermostat is just bad!? I'm going to borrow my friend's infrared thermometer tomorrow and find out the real temp once and for all.

 

You'll need to get replacement carbon brushes for the pump, its 99% down to them, especially since you clearly never replaced them.
All details here:
Jaguar XJ6; Jaguar X300; Heater Pump
Replacement brushes need to be 4mm x 4mm x 7 or 8mm long. You can file down 5mm ones if you wont have access to 4mm ones. Takes a couple of hours to do it first time.

 

A non running electric pump will still have some flow at higher engine RPMs

The pulleys on the crankshaft harmonic balancer can fail to spin explaining your no coolant flow though the engine block

You can tap on the electric coolant motor with a broom handle to free up what is left of the brushes

There are aged rubber mounts under the electric motor so don't tap too hard

The electric pomp will run at all times in heat mode selection , the solenoid will throttle the coolant flow on and off

The brush # is 33A ( X 2 ) from Eurtonelectric out of California

Double checking that last information

.15" x .15" x .35" BRUSH 33A (eurtonelectric.com)

and

33A Brush - Part Number 49201010 - Bodine Electric (bodine-electric.com)

And maybe for Germany

1 X KOHLEBÜRSTEN - SATZ ( 2STK. ) / CARBON BRUSH SET ( 2PCS. )


B x H x L
8 x 5 x 15,5

MONARK KOHLEBÜRSTEN SET FÜR BOSCH 14V 13 - 33A LICHTMASCHINE VERGL NR 1127014008 | eBay

 

I borrowed my friend's infrared thermometer and the radiator hoses read about 120 F. That much too low, correct?

 

Yes

the fans will kick on a 86 and 100 degree C

If the TSB has been done it will always have low running fan mode

The engine thermostat should keep it slightly over 88 C on the engine side of the main water pump

 

G'day Jomo,

The heater valve is open with power off and closes with power applied so unless it is jammed shut it should open if you disconnect the plug. With the car running and heating selected the heater pump should run and you can check this by feeling it. Often these pumps wear out the electrical brushes and then fail. It is a pretty easy job to open up the pump, if it has failed, and although OEM replacement bushes are no longer available you should be able to get something similar from an auto electrician and then file them to fit your pump. Search the forum and you'll find a lot of info.

The heating in my car was poor when I bought the car and it was a clogged heater matrix but this would not be the cause a sudden failure as you have reported.

Cheers and good luck,
Jeff.

 

If you change the thermostat , it does not take a large O - ring , even if it comes with one

breaks the housing casting on clamp down

 

Great advise. The AJ6 engine needs the 'O'ring, the AJ16 needs the flat gasket.

 

Too low.

I remember trying to perform 'Oxygen Orientation Setup' (warranty recall service for ECM PROMS) when I worked at the dealer and if the engine did not reach 88 degrees Centigrade, the test/setup would not commence.

Customers would decline a thermostat change to remedy so I would 'pinch-off' the radiator hose to get the engine hot enough to complete the Orientation.

I would remove the 'pinch-off' pliers and return the car to the customer after the RECALL was done.

Summertime thermostat faults were not noticed but an 'OPEN' thermostat in WINTER was obvious.

 

I installed a new thermostat. The gun shows that the water is a bit hotter than before the thermostat replacement. What I did observe is that one line at the heater core (the inlet I guess) is much hotter than the other line (the outlet(?)). Does this mean that my heater core is blocked?

 

i went through this a while back, and looked at everything. in the end new brushes in the pump motor is what was needed

 

There is a design flaw in the hoses around the electric coolant pump motor and the heater / matrix hose coolant solenoid

This was corrected on the same heater system on the V8 X308

This was changed with a check valve added to not get strange flows

Thanks Bob on the flat gasket on the thermostat for the X300 / AJ16

A slug blocked heater core / matrix is possible

There was something about different types of coolant can not be mixed and forms sludge

This other than the original sludge blocking with the original coolant type alone

 

Happy New Year.
I pulled the motor, the brushes are intact but the motor doesn't spin when I apply 12v. Bad motor, oh well!
Jomo

 

There is a capacitor involved

To test the capacitor put a meter on resistance check and with the capacitor electrically isolated the resistance should climb in value and then reset

You are in effect charging the capacitor until it cycles , this proves a good capacitor

Have you tested the relays involved , there is one control fuse off the top of my head

But then your direct powering of the motor test

To buy the electric motor can be expensive but there is a alternate motor / pump impellor assembly from Bosch

 

Yes, I did check the resistor when the motor wouldn't spin. Thanks for mentioning that. Can you tell me how to find the model from Bosch that I can use.
Thanks!